social psychology experiments

• The 25 Most Influential Psychological Experiments in History

While each year thousands and thousands of studies are completed in the many specialty areas of psychology, there are a handful that, over the years, have had a lasting impact in the psychological community as a whole. Some of these were dutifully conducted, keeping within the confines of ethical and practical guidelines. Others pushed the boundaries of human behavior during their psychological experiments and created controversies that still linger to this day. And still others were not designed to be true psychological experiments, but ended up as beacons to the psychological community in proving or disproving theories.

This is a list of the 25 most influential psychological experiments still being taught to psychology students of today.

1. A Class Divided

Study conducted by: jane elliott.

Study Conducted in 1968 in an Iowa classroom

Experiment Details: Jane Elliott’s famous experiment was inspired by the assassination of Dr. Martin Luther King Jr. and the inspirational life that he led. The third grade teacher developed an exercise, or better yet, a psychological experiment, to help her Caucasian students understand the effects of racism and prejudice.

Elliott divided her class into two separate groups: blue-eyed students and brown-eyed students. On the first day, she labeled the blue-eyed group as the superior group and from that point forward they had extra privileges, leaving the brown-eyed children to represent the minority group. She discouraged the groups from interacting and singled out individual students to stress the negative characteristics of the children in the minority group. What this exercise showed was that the children’s behavior changed almost instantaneously. The group of blue-eyed students performed better academically and even began bullying their brown-eyed classmates. The brown-eyed group experienced lower self-confidence and worse academic performance. The next day, she reversed the roles of the two groups and the blue-eyed students became the minority group.

At the end of the experiment, the children were so relieved that they were reported to have embraced one another and agreed that people should not be judged based on outward appearances. This exercise has since been repeated many times with similar outcomes.

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2. Asch Conformity Study

Study conducted by: dr. solomon asch.

Study Conducted in 1951 at Swarthmore College

Experiment Details: Dr. Solomon Asch conducted a groundbreaking study that was designed to evaluate a person’s likelihood to conform to a standard when there is pressure to do so.

A group of participants were shown pictures with lines of various lengths and were then asked a simple question: Which line is longest? The tricky part of this study was that in each group only one person was a true participant. The others were actors with a script. Most of the actors were instructed to give the wrong answer. Strangely, the one true participant almost always agreed with the majority, even though they knew they were giving the wrong answer.

The results of this study are important when we study social interactions among individuals in groups. This study is a famous example of the temptation many of us experience to conform to a standard during group situations and it showed that people often care more about being the same as others than they do about being right. It is still recognized as one of the most influential psychological experiments for understanding human behavior.

3. Bobo Doll Experiment

Study conducted by: dr. alburt bandura.

Study Conducted between 1961-1963 at Stanford University

In his groundbreaking study he separated participants into three groups:

• one was exposed to a video of an adult showing aggressive behavior towards a Bobo doll
• another was exposed to video of a passive adult playing with the Bobo doll
• the third formed a control group

Children watched their assigned video and then were sent to a room with the same doll they had seen in the video (with the exception of those in the control group). What the researcher found was that children exposed to the aggressive model were more likely to exhibit aggressive behavior towards the doll themselves. The other groups showed little imitative aggressive behavior. For those children exposed to the aggressive model, the number of derivative physical aggressions shown by the boys was 38.2 and 12.7 for the girls.

The study also showed that boys exhibited more aggression when exposed to aggressive male models than boys exposed to aggressive female models. When exposed to aggressive male models, the number of aggressive instances exhibited by boys averaged 104. This is compared to 48.4 aggressive instances exhibited by boys who were exposed to aggressive female models.

While the results for the girls show similar findings, the results were less drastic. When exposed to aggressive female models, the number of aggressive instances exhibited by girls averaged 57.7. This is compared to 36.3 aggressive instances exhibited by girls who were exposed to aggressive male models. The results concerning gender differences strongly supported Bandura’s secondary prediction that children will be more strongly influenced by same-sex models. The Bobo Doll Experiment showed a groundbreaking way to study human behavior and it’s influences.

4. Car Crash Experiment

Study conducted by: elizabeth loftus and john palmer.

Study Conducted in 1974 at The University of California in Irvine

The participants watched slides of a car accident and were asked to describe what had happened as if they were eyewitnesses to the scene. The participants were put into two groups and each group was questioned using different wording such as “how fast was the car driving at the time of impact?” versus “how fast was the car going when it smashed into the other car?” The experimenters found that the use of different verbs affected the participants’ memories of the accident, showing that memory can be easily distorted.

This research suggests that memory can be easily manipulated by questioning technique. This means that information gathered after the event can merge with original memory causing incorrect recall or reconstructive memory. The addition of false details to a memory of an event is now referred to as confabulation. This concept has very important implications for the questions used in police interviews of eyewitnesses.

5. Cognitive Dissonance Experiment

Study conducted by: leon festinger and james carlsmith.

Study Conducted in 1957 at Stanford University

Experiment Details: The concept of cognitive dissonance refers to a situation involving conflicting:

This conflict produces an inherent feeling of discomfort leading to a change in one of the attitudes, beliefs or behaviors to minimize or eliminate the discomfort and restore balance.

Cognitive dissonance was first investigated by Leon Festinger, after an observational study of a cult that believed that the earth was going to be destroyed by a flood. Out of this study was born an intriguing experiment conducted by Festinger and Carlsmith where participants were asked to perform a series of dull tasks (such as turning pegs in a peg board for an hour). Participant’s initial attitudes toward this task were highly negative.

They were then paid either $1 or $20 to tell a participant waiting in the lobby that the tasks were really interesting. Almost all of the participants agreed to walk into the waiting room and persuade the next participant that the boring experiment would be fun. When the participants were later asked to evaluate the experiment, the participants who were paid only $1 rated the tedious task as more fun and enjoyable than the participants who were paid $20 to lie.

Being paid only $1 is not sufficient incentive for lying and so those who were paid $1 experienced dissonance. They could only overcome that cognitive dissonance by coming to believe that the tasks really were interesting and enjoyable. Being paid $20 provides a reason for turning pegs and there is therefore no dissonance.

6. Fantz’s Looking Chamber

Study conducted by: robert l. fantz.

Study Conducted in 1961 at the University of Illinois

Experiment Details: The study conducted by Robert L. Fantz is among the simplest, yet most important in the field of infant development and vision. In 1961, when this experiment was conducted, there very few ways to study what was going on in the mind of an infant. Fantz realized that the best way was to simply watch the actions and reactions of infants. He understood the fundamental factor that if there is something of interest near humans, they generally look at it.

To test this concept, Fantz set up a display board with two pictures attached. On one was a bulls-eye. On the other was the sketch of a human face. This board was hung in a chamber where a baby could lie safely underneath and see both images. Then, from behind the board, invisible to the baby, he peeked through a hole to watch what the baby looked at. This study showed that a two-month old baby looked twice as much at the human face as it did at the bulls-eye. This suggests that human babies have some powers of pattern and form selection. Before this experiment it was thought that babies looked out onto a chaotic world of which they could make little sense.

7. Hawthorne Effect

Study conducted by: henry a. landsberger.

Study Conducted in 1955 at Hawthorne Works in Chicago, Illinois

Landsberger performed the study by analyzing data from experiments conducted between 1924 and 1932, by Elton Mayo, at the Hawthorne Works near Chicago. The company had commissioned studies to evaluate whether the level of light in a building changed the productivity of the workers. What Mayo found was that the level of light made no difference in productivity. The workers increased their output whenever the amount of light was switched from a low level to a high level, or vice versa.

The researchers noticed a tendency that the workers’ level of efficiency increased when any variable was manipulated. The study showed that the output changed simply because the workers were aware that they were under observation. The conclusion was that the workers felt important because they were pleased to be singled out. They increased productivity as a result. Being singled out was the factor dictating increased productivity, not the changing lighting levels, or any of the other factors that they experimented upon.

The Hawthorne Effect has become one of the hardest inbuilt biases to eliminate or factor into the design of any experiment in psychology and beyond.

8. Kitty Genovese Case

Study conducted by: new york police force.

Study Conducted in 1964 in New York City

Experiment Details: The murder case of Kitty Genovese was never intended to be a psychological experiment, however it ended up having serious implications for the field.

According to a New York Times article, almost 40 neighbors witnessed Kitty Genovese being savagely attacked and murdered in Queens, New York in 1964. Not one neighbor called the police for help. Some reports state that the attacker briefly left the scene and later returned to “finish off” his victim. It was later uncovered that many of these facts were exaggerated. (There were more likely only a dozen witnesses and records show that some calls to police were made).

What this case later become famous for is the “Bystander Effect,” which states that the more bystanders that are present in a social situation, the less likely it is that anyone will step in and help. This effect has led to changes in medicine, psychology and many other areas. One famous example is the way CPR is taught to new learners. All students in CPR courses learn that they must assign one bystander the job of alerting authorities which minimizes the chances of no one calling for assistance.

9. Learned Helplessness Experiment

Study conducted by: martin seligman.

Study Conducted in 1967 at the University of Pennsylvania

Seligman’s experiment involved the ringing of a bell and then the administration of a light shock to a dog. After a number of pairings, the dog reacted to the shock even before it happened. As soon as the dog heard the bell, he reacted as though he’d already been shocked.

During the course of this study something unexpected happened. Each dog was placed in a large crate that was divided down the middle with a low fence. The dog could see and jump over the fence easily. The floor on one side of the fence was electrified, but not on the other side of the fence. Seligman placed each dog on the electrified side and administered a light shock. He expected the dog to jump to the non-shocking side of the fence. In an unexpected turn, the dogs simply laid down.

The hypothesis was that as the dogs learned from the first part of the experiment that there was nothing they could do to avoid the shocks, they gave up in the second part of the experiment. To prove this hypothesis the experimenters brought in a new set of animals and found that dogs with no history in the experiment would jump over the fence.

This condition was described as learned helplessness. A human or animal does not attempt to get out of a negative situation because the past has taught them that they are helpless.

10. Little Albert Experiment

Study conducted by: john b. watson and rosalie rayner.

Study Conducted in 1920 at Johns Hopkins University

The experiment began by placing a white rat in front of the infant, who initially had no fear of the animal. Watson then produced a loud sound by striking a steel bar with a hammer every time little Albert was presented with the rat. After several pairings (the noise and the presentation of the white rat), the boy began to cry and exhibit signs of fear every time the rat appeared in the room. Watson also created similar conditioned reflexes with other common animals and objects (rabbits, Santa beard, etc.) until Albert feared them all.

This study proved that classical conditioning works on humans. One of its most important implications is that adult fears are often connected to early childhood experiences.

11. Magical Number Seven

Study conducted by: george a. miller.

Study Conducted in 1956 at Princeton University

Experiment Details:   Frequently referred to as “ Miller’s Law,” the Magical Number Seven experiment purports that the number of objects an average human can hold in working memory is 7 ± 2. This means that the human memory capacity typically includes strings of words or concepts ranging from 5-9. This information on the limits to the capacity for processing information became one of the most highly cited papers in psychology.

The Magical Number Seven Experiment was published in 1956 by cognitive psychologist George A. Miller of Princeton University’s Department of Psychology in Psychological Review .  In the article, Miller discussed a concurrence between the limits of one-dimensional absolute judgment and the limits of short-term memory.

In a one-dimensional absolute-judgment task, a person is presented with a number of stimuli that vary on one dimension (such as 10 different tones varying only in pitch). The person responds to each stimulus with a corresponding response (learned before).

Performance is almost perfect up to five or six different stimuli but declines as the number of different stimuli is increased. This means that a human’s maximum performance on one-dimensional absolute judgment can be described as an information store with the maximum capacity of approximately 2 to 3 bits of information There is the ability to distinguish between four and eight alternatives.

12. Pavlov’s Dog Experiment

Study conducted by: ivan pavlov.

Study Conducted in the 1890s at the Military Medical Academy in St. Petersburg, Russia

Pavlov began with the simple idea that there are some things that a dog does not need to learn. He observed that dogs do not learn to salivate when they see food. This reflex is “hard wired” into the dog. This is an unconditioned response (a stimulus-response connection that required no learning).

Pavlov outlined that there are unconditioned responses in the animal by presenting a dog with a bowl of food and then measuring its salivary secretions. In the experiment, Pavlov used a bell as his neutral stimulus. Whenever he gave food to his dogs, he also rang a bell. After a number of repeats of this procedure, he tried the bell on its own. What he found was that the bell on its own now caused an increase in salivation. The dog had learned to associate the bell and the food. This learning created a new behavior. The dog salivated when he heard the bell. Because this response was learned (or conditioned), it is called a conditioned response. The neutral stimulus has become a conditioned stimulus.

This theory came to be known as classical conditioning.

13. Robbers Cave Experiment

Study conducted by: muzafer and carolyn sherif.

Study Conducted in 1954 at the University of Oklahoma

Experiment Details: This experiment, which studied group conflict, is considered by most to be outside the lines of what is considered ethically sound.

In 1954 researchers at the University of Oklahoma assigned 22 eleven- and twelve-year-old boys from similar backgrounds into two groups. The two groups were taken to separate areas of a summer camp facility where they were able to bond as social units. The groups were housed in separate cabins and neither group knew of the other’s existence for an entire week. The boys bonded with their cabin mates during that time. Once the two groups were allowed to have contact, they showed definite signs of prejudice and hostility toward each other even though they had only been given a very short time to develop their social group. To increase the conflict between the groups, the experimenters had them compete against each other in a series of activities. This created even more hostility and eventually the groups refused to eat in the same room. The final phase of the experiment involved turning the rival groups into friends. The fun activities the experimenters had planned like shooting firecrackers and watching movies did not initially work, so they created teamwork exercises where the two groups were forced to collaborate. At the end of the experiment, the boys decided to ride the same bus home, demonstrating that conflict can be resolved and prejudice overcome through cooperation.

Many critics have compared this study to Golding’s Lord of the Flies novel as a classic example of prejudice and conflict resolution.

14. Ross’ False Consensus Effect Study

Study conducted by: lee ross.

Study Conducted in 1977 at Stanford University

Experiment Details: In 1977, a social psychology professor at Stanford University named Lee Ross conducted an experiment that, in lay terms, focuses on how people can incorrectly conclude that others think the same way they do, or form a “false consensus” about the beliefs and preferences of others. Ross conducted the study in order to outline how the “false consensus effect” functions in humans.

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In the first part of the study, participants were asked to read about situations in which a conflict occurred and then were told two alternative ways of responding to the situation. They were asked to do three things:

• Guess which option other people would choose
• Say which option they themselves would choose
• Describe the attributes of the person who would likely choose each of the two options

What the study showed was that most of the subjects believed that other people would do the same as them, regardless of which of the two responses they actually chose themselves. This phenomenon is referred to as the false consensus effect, where an individual thinks that other people think the same way they do when they may not. The second observation coming from this important study is that when participants were asked to describe the attributes of the people who will likely make the choice opposite of their own, they made bold and sometimes negative predictions about the personalities of those who did not share their choice.

15. The Schachter and Singer Experiment on Emotion

Study conducted by: stanley schachter and jerome e. singer.

Study Conducted in 1962 at Columbia University

Experiment Details: In 1962 Schachter and Singer conducted a ground breaking experiment to prove their theory of emotion.

In the study, a group of 184 male participants were injected with epinephrine, a hormone that induces arousal including increased heartbeat, trembling, and rapid breathing. The research participants were told that they were being injected with a new medication to test their eyesight. The first group of participants was informed the possible side effects that the injection might cause while the second group of participants were not. The participants were then placed in a room with someone they thought was another participant, but was actually a confederate in the experiment. The confederate acted in one of two ways: euphoric or angry. Participants who had not been informed about the effects of the injection were more likely to feel either happier or angrier than those who had been informed.

What Schachter and Singer were trying to understand was the ways in which cognition or thoughts influence human emotion. Their study illustrates the importance of how people interpret their physiological states, which form an important component of your emotions. Though their cognitive theory of emotional arousal dominated the field for two decades, it has been criticized for two main reasons: the size of the effect seen in the experiment was not that significant and other researchers had difficulties repeating the experiment.

16. Selective Attention / Invisible Gorilla Experiment

Study conducted by: daniel simons and christopher chabris.

Study Conducted in 1999 at Harvard University

Experiment Details: In 1999 Simons and Chabris conducted their famous awareness test at Harvard University.

Participants in the study were asked to watch a video and count how many passes occurred between basketball players on the white team. The video moves at a moderate pace and keeping track of the passes is a relatively easy task. What most people fail to notice amidst their counting is that in the middle of the test, a man in a gorilla suit walked onto the court and stood in the center before walking off-screen.

The study found that the majority of the subjects did not notice the gorilla at all, proving that humans often overestimate their ability to effectively multi-task. What the study set out to prove is that when people are asked to attend to one task, they focus so strongly on that element that they may miss other important details.

17. Stanford Prison Study

Study conducted by philip zimbardo.

Study Conducted in 1971 at Stanford University

The Stanford Prison Experiment was designed to study behavior of “normal” individuals when assigned a role of prisoner or guard. College students were recruited to participate. They were assigned roles of “guard” or “inmate.”  Zimbardo played the role of the warden. The basement of the psychology building was the set of the prison. Great care was taken to make it look and feel as realistic as possible.

The prison guards were told to run a prison for two weeks. They were told not to physically harm any of the inmates during the study. After a few days, the prison guards became very abusive verbally towards the inmates. Many of the prisoners became submissive to those in authority roles. The Stanford Prison Experiment inevitably had to be cancelled because some of the participants displayed troubling signs of breaking down mentally.

Although the experiment was conducted very unethically, many psychologists believe that the findings showed how much human behavior is situational. People will conform to certain roles if the conditions are right. The Stanford Prison Experiment remains one of the most famous psychology experiments of all time.

18. Stanley Milgram Experiment

Study conducted by stanley milgram.

Study Conducted in 1961 at Stanford University

Experiment Details: This 1961 study was conducted by Yale University psychologist Stanley Milgram. It was designed to measure people’s willingness to obey authority figures when instructed to perform acts that conflicted with their morals. The study was based on the premise that humans will inherently take direction from authority figures from very early in life.

Participants were told they were participating in a study on memory. They were asked to watch another person (an actor) do a memory test. They were instructed to press a button that gave an electric shock each time the person got a wrong answer. (The actor did not actually receive the shocks, but pretended they did).

Participants were told to play the role of “teacher” and administer electric shocks to “the learner,” every time they answered a question incorrectly. The experimenters asked the participants to keep increasing the shocks. Most of them obeyed even though the individual completing the memory test appeared to be in great pain. Despite these protests, many participants continued the experiment when the authority figure urged them to. They increased the voltage after each wrong answer until some eventually administered what would be lethal electric shocks.

This experiment showed that humans are conditioned to obey authority and will usually do so even if it goes against their natural morals or common sense.

19. Surrogate Mother Experiment

Study conducted by: harry harlow.

Study Conducted from 1957-1963 at the University of Wisconsin

Experiment Details: In a series of controversial experiments during the late 1950s and early 1960s, Harry Harlow studied the importance of a mother’s love for healthy childhood development.

In order to do this he separated infant rhesus monkeys from their mothers a few hours after birth and left them to be raised by two “surrogate mothers.” One of the surrogates was made of wire with an attached bottle for food. The other was made of soft terrycloth but lacked food. The researcher found that the baby monkeys spent much more time with the cloth mother than the wire mother, thereby proving that affection plays a greater role than sustenance when it comes to childhood development. They also found that the monkeys that spent more time cuddling the soft mother grew up to healthier.

This experiment showed that love, as demonstrated by physical body contact, is a more important aspect of the parent-child bond than the provision of basic needs. These findings also had implications in the attachment between fathers and their infants when the mother is the source of nourishment.

20. The Good Samaritan Experiment

Study conducted by: john darley and daniel batson.

Study Conducted in 1973 at The Princeton Theological Seminary (Researchers were from Princeton University)

Experiment Details: In 1973, an experiment was created by John Darley and Daniel Batson, to investigate the potential causes that underlie altruistic behavior. The researchers set out three hypotheses they wanted to test:

• People thinking about religion and higher principles would be no more inclined to show helping behavior than laymen.
• People in a rush would be much less likely to show helping behavior.
• People who are religious for personal gain would be less likely to help than people who are religious because they want to gain some spiritual and personal insights into the meaning of life.

Student participants were given some religious teaching and instruction. They were then were told to travel from one building to the next. Between the two buildings was a man lying injured and appearing to be in dire need of assistance. The first variable being tested was the degree of urgency impressed upon the subjects, with some being told not to rush and others being informed that speed was of the essence.

The results of the experiment were intriguing, with the haste of the subject proving to be the overriding factor. When the subject was in no hurry, nearly two-thirds of people stopped to lend assistance. When the subject was in a rush, this dropped to one in ten.

People who were on the way to deliver a speech about helping others were nearly twice as likely to help as those delivering other sermons,. This showed that the thoughts of the individual were a factor in determining helping behavior. Religious beliefs did not appear to make much difference on the results. Being religious for personal gain, or as part of a spiritual quest, did not appear to make much of an impact on the amount of helping behavior shown.

21. The Halo Effect Experiment

Study conducted by: richard e. nisbett and timothy decamp wilson.

Study Conducted in 1977 at the University of Michigan

Experiment Details: The Halo Effect states that people generally assume that people who are physically attractive are more likely to:

• be intelligent
• be friendly
• display good judgment

To prove their theory, Nisbett and DeCamp Wilson created a study to prove that people have little awareness of the nature of the Halo Effect. They’re not aware that it influences:

• their personal judgments
• the production of a more complex social behavior

In the experiment, college students were the research participants. They were asked to evaluate a psychology instructor as they view him in a videotaped interview. The students were randomly assigned to one of two groups. Each group was shown one of two different interviews with the same instructor. The instructor is a native French-speaking Belgian who spoke English with a noticeable accent. In the first video, the instructor presented himself as someone:

• respectful of his students’ intelligence and motives
• flexible in his approach to teaching
• enthusiastic about his subject matter

In the second interview, he presented himself as much more unlikable. He was cold and distrustful toward the students and was quite rigid in his teaching style.

After watching the videos, the subjects were asked to rate the lecturer on:

• physical appearance

His mannerisms and accent were kept the same in both versions of videos. The subjects were asked to rate the professor on an 8-point scale ranging from “like extremely” to “dislike extremely.” Subjects were also told that the researchers were interested in knowing “how much their liking for the teacher influenced the ratings they just made.” Other subjects were asked to identify how much the characteristics they just rated influenced their liking of the teacher.

After responding to the questionnaire, the respondents were puzzled about their reactions to the videotapes and to the questionnaire items. The students had no idea why they gave one lecturer higher ratings. Most said that how much they liked the lecturer had not affected their evaluation of his individual characteristics at all.

The interesting thing about this study is that people can understand the phenomenon, but they are unaware when it is occurring. Without realizing it, humans make judgments. Even when it is pointed out, they may still deny that it is a product of the halo effect phenomenon.

22. The Marshmallow Test

Study conducted by: walter mischel.

Study Conducted in 1972 at Stanford University

In his 1972 Marshmallow Experiment, children ages four to six were taken into a room where a marshmallow was placed in front of them on a table. Before leaving each of the children alone in the room, the experimenter informed them that they would receive a second marshmallow if the first one was still on the table after they returned in 15 minutes. The examiner recorded how long each child resisted eating the marshmallow and noted whether it correlated with the child’s success in adulthood. A small number of the 600 children ate the marshmallow immediately and one-third delayed gratification long enough to receive the second marshmallow.

In follow-up studies, Mischel found that those who deferred gratification were significantly more competent and received higher SAT scores than their peers. This characteristic likely remains with a person for life. While this study seems simplistic, the findings outline some of the foundational differences in individual traits that can predict success.

23. The Monster Study

Study conducted by: wendell johnson.

Study Conducted in 1939 at the University of Iowa

Experiment Details: The Monster Study received this negative title due to the unethical methods that were used to determine the effects of positive and negative speech therapy on children.

Wendell Johnson of the University of Iowa selected 22 orphaned children, some with stutters and some without. The children were in two groups. The group of children with stutters was placed in positive speech therapy, where they were praised for their fluency. The non-stutterers were placed in negative speech therapy, where they were disparaged for every mistake in grammar that they made.

As a result of the experiment, some of the children who received negative speech therapy suffered psychological effects and retained speech problems for the rest of their lives. They were examples of the significance of positive reinforcement in education.

The initial goal of the study was to investigate positive and negative speech therapy. However, the implication spanned much further into methods of teaching for young children.

24. Violinist at the Metro Experiment

Study conducted by: staff at the washington post.

Study Conducted in 2007 at a Washington D.C. Metro Train Station

During the study, pedestrians rushed by without realizing that the musician playing at the entrance to the metro stop was Grammy-winning musician, Joshua Bell. Two days before playing in the subway, he sold out at a theater in Boston where the seats average $100. He played one of the most intricate pieces ever written with a violin worth 3.5 million dollars. In the 45 minutes the musician played his violin, only 6 people stopped and stayed for a while. Around 20 gave him money, but continued to walk their normal pace. He collected $32.

The study and the subsequent article organized by the Washington Post was part of a social experiment looking at:

• the priorities of people

Gene Weingarten wrote about the social experiment: “In a banal setting at an inconvenient time, would beauty transcend?” Later he won a Pulitzer Prize for his story. Some of the questions the article addresses are:

• Do we perceive beauty?
• Do we stop to appreciate it?
• Do we recognize the talent in an unexpected context?

As it turns out, many of us are not nearly as perceptive to our environment as we might like to think.

25. Visual Cliff Experiment

Study conducted by: eleanor gibson and richard walk.

Study Conducted in 1959 at Cornell University

Experiment Details: In 1959, psychologists Eleanor Gibson and Richard Walk set out to study depth perception in infants. They wanted to know if depth perception is a learned behavior or if it is something that we are born with. To study this, Gibson and Walk conducted the visual cliff experiment.

They studied 36 infants between the ages of six and 14 months, all of whom could crawl. The infants were placed one at a time on a visual cliff. A visual cliff was created using a large glass table that was raised about a foot off the floor. Half of the glass table had a checker pattern underneath in order to create the appearance of a ‘shallow side.’

In order to create a ‘deep side,’ a checker pattern was created on the floor; this side is the visual cliff. The placement of the checker pattern on the floor creates the illusion of a sudden drop-off. Researchers placed a foot-wide centerboard between the shallow side and the deep side. Gibson and Walk found the following:

• Nine of the infants did not move off the centerboard.
• All of the 27 infants who did move crossed into the shallow side when their mothers called them from the shallow side.
• Three of the infants crawled off the visual cliff toward their mother when called from the deep side.
• When called from the deep side, the remaining 24 children either crawled to the shallow side or cried because they could not cross the visual cliff and make it to their mother.

What this study helped demonstrate is that depth perception is likely an inborn train in humans.

Among these experiments and psychological tests, we see boundaries pushed and theories taking on a life of their own. It is through the endless stream of psychological experimentation that we can see simple hypotheses become guiding theories for those in this field. The greater field of psychology became a formal field of experimental study in 1879, when Wilhelm Wundt established the first laboratory dedicated solely to psychological research in Leipzig, Germany. Wundt was the first person to refer to himself as a psychologist. Since 1879, psychology has grown into a massive collection of:

• methods of practice

It’s also a specialty area in the field of healthcare. None of this would have been possible without these and many other important psychological experiments that have stood the test of time.

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About the Author

After earning a Bachelor of Arts in Psychology from Rutgers University and then a Master of Science in Clinical and Forensic Psychology from Drexel University, Kristen began a career as a therapist at two prisons in Philadelphia. At the same time she volunteered as a rape crisis counselor, also in Philadelphia. After a few years in the field she accepted a teaching position at a local college where she currently teaches online psychology courses. Kristen began writing in college and still enjoys her work as a writer, editor, professor and mother.

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The Most Famous Social Psychology Experiments Ever Performed

Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

Emily Swaim is a board-certified science editor who has worked with top digital publishing brands like Voices for Biodiversity, Study.com, GoodTherapy, and Vox.

Social experiments often seek to answer questions about how people behave in groups or how the presence of others impacts individual behavior. Over the years, social psychologists have explored these questions by conducting experiments .

The results of some of the most famous social psychology experiments remain relevant (and often quite controversial) today. Such experiments give us valuable information about human behavior and how group influence can impact our actions in social situations.

At a Glance

Some of the most famous social psychology experiments include Asch's conformity experiments, Bandura's Bobo doll experiments, the Stanford prison experiment, and Milgram's obedience experiments. Some of these studies are quite controversial for various reasons, including how they were conducted, serious ethical concerns, and what their results suggested.

The Asch Conformity Experiments

What do you do when you know you're right but the rest of the group disagrees with you? Do you bow to group pressure?

In a series of famous experiments conducted during the 1950s, psychologist Solomon Asch demonstrated that people would give the wrong answer on a test to fit in with the rest of the group.

In Asch's famous conformity experiments , people were shown a line and then asked to select a line of a matching length from a group of three. Asch also placed confederates in the group who would intentionally choose the wrong lines.

The results revealed that when other people picked the wrong line, participants were likely to conform and give the same answers as the rest of the group.

What the Results Revealed

While we might like to believe that we would resist group pressure (especially when we know the group is wrong), Asch's results revealed that people are surprisingly susceptible to conformity .

Not only did Asch's experiment teach us a great deal about the power of conformity, but it also inspired a whole host of additional research on how people conform and obey, including Milgram's infamous obedience experiments.

The Bobo Doll Experiment

Does watching violence on television cause children to behave more aggressively? In a series of experiments conducted during the early 1960s, psychologist Albert Bandura set out to investigate the impact of observed aggression on children's behavior.

In his Bobo doll experiments , children would watch an adult interacting with a Bobo doll. In one condition, the adult model behaved passively toward the doll, but in another, the adult would kick, punch, strike, and yell at the doll.

The results revealed that children who watched the adult model behave violently toward the doll were likelier to imitate the aggressive behavior later on.​

The Impact of Bandura's Social Psychology Experiment

The debate over the degree to which violence on television, movies, gaming, and other media influences children's behavior continues to rage on today, so it perhaps comes as no surprise that Bandura's findings are still so relevant.

The experiment has also helped inspire hundreds of additional studies exploring the impacts of observed aggression and violence.

The Stanford Prison Experiment

During the early 1970s, Philip Zimbardo set up a fake prison in the basement of the Stanford Psychology Department, recruited participants to play prisoners and guards, and played the role of the prison warden.

The experiment was designed to look at the effect that a prison environment would have on behavior, but it quickly became one of the most famous and controversial experiments of all time.

Results of the Stanford Prison Experiment

The Stanford prison experiment was initially slated to last a full two weeks. It ended after just six days. Why? Because the participants became so enmeshed in their assumed roles, the guards became almost sadistically abusive, and the prisoners became anxious, depressed, and emotionally disturbed.

While the Stanford prison experiment was designed to look at prison behavior, it has since become an emblem of how powerfully people are influenced by situations.  

Ethical Concerns

Part of the notoriety stems from the study's treatment of the participants. The subjects were placed in a situation that created considerable psychological distress. So much so that the study had to be halted less than halfway through the experiment.

The study has long been upheld as an example of how people yield to the situation, but critics have suggested that the participants' behavior may have been unduly influenced by Zimbardo himself in his capacity as the mock prison's "warden."  

Recent Criticisms

The Stanford prison experiment has long been controversial due to the serious ethical concerns of the research, but more recent evidence casts serious doubts on the study's scientific merits.

An examination of study records indicates participants faked their behavior to either get out of the experiment or "help" prove the researcher's hypothesis. The experimenters also appear to have encouraged certain behaviors to help foster more abusive behavior.

The Milgram Experiments

Following the trial of Adolph Eichmann for war crimes committed during World War II, psychologist Stanley Milgram wanted to better understand why people obey. "Could it be that Eichmann and his million accomplices in the Holocaust were just following orders? Could we call them all accomplices?" Milgram wondered.

The results of Milgram's controversial obedience experiments were astonishing and continue to be both thought-provoking and controversial today.

What the Social Psychology Experiment Involved

The study involved ordering participants to deliver increasingly painful shocks to another person. While the victim was simply a confederate pretending to be injured, the participants fully believed that they were giving electrical shocks to the other person.

Even when the victim was protesting or complaining of a heart condition, 65% of the participants continued to deliver painful, possibly fatal shocks on the experimenter's orders.

Obviously, no one wants to believe that they are capable of inflicting pain or torture on another human being simply on the orders of an authority figure. The results of the obedience experiments are disturbing because they reveal that people are much more obedient than they may believe.

Controversy and Recent Criticisms

The study is also controversial because it suffers from ethical concerns, primarily the psychological distress it created for the participants. More recent findings suggest that other problems question the study's findings.

Some participants were coerced into continuing against their wishes. Many participants appeared to have guessed that the learner was faking their responses, and other variations showed that many participants refused to continue the shocks.

What This Means For You

There are many interesting and famous social psychology experiments that can reveal a lot about our understanding of social behavior and influence. However, it is important to be aware of the controversies, limitations, and criticisms of these studies. More recent research may reflect differing results. In some cases, the re-evaluation of classic studies has revealed serious ethical and methodological flaws that call the results into question.

Jeon, HL.  The environmental factor within the Solomon Asch Line Test .  International Journal of Social Science and Humanity.  2014;4(4):264-268. doi:10.7763/IJSSH.2014.V4.360 

Bandura and Bobo . Association for Psychological Science.

Zimbardo, G. The Stanford Prison Experiment: a simulation study on the psychology of imprisonment .

Le Texier T.  Debunking the Stanford Prison Experiment.   Am Psychol.  2019;74(7):823-839. doi:10.1037/amp0000401

Blum B.  The lifespan of a lie .  Medium .

Baker PC. Electric Schlock: Did Stanley Milgram's famous obedience experiments prove anything? Pacific Standard .

Perry G.  Deception and illusion in Milgram's accounts of the obedience experiments .  Theory Appl Ethics . 2013;2(2):79-92.

By Kendra Cherry, MSEd Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

9 of the Most Influential Social Psychology Experiments in History

For those interested in understanding how social interactions can shape behavior and mental processes, this article dives deep into some of the most influential social psychology experiments in history. Covering everything from the perpetrator-victim dynamic prevalent in Stanley Milgram’s infamous obedience experiment to the false consensus effect just a few years later, these social psychology experiments provide invaluable insights into the human psyche.

Through carefully conducted studies such as Lee Ross’ Diffusion of Responsibility Experiment and Edward Thorndike’s Halo Effect Experiment, as well as famous experiments such as Albert Bandura’s Bobo Doll Experiment, we are able to better comprehend why people act the way they do in certain situations. Come explore these incredible, influential experiments that have left their mark on social psychology and the world!

To learn more about what is social psychology check out our article.

The Stanford Prison Experiment, 1971

1.1. overview.

The Stanford Prison Experiment was a widely known and controversial social psychology experiment conducted in 1971 at Stanford University by Professor Philip Zimbardo to investigate how ordinary, healthy people would react to being made prisoners or prison guards. It has since become a classic social psychology experiment and is still studied today. However, the experiment has come under considerable criticism in recent years due to ethical issues.

1.2. Results

Twenty-four male college students were recruited for the experiment, which involved them playing the role of either prisoner or guard. Each group was then allotted 8-hour shifts and treated as if they were in a real prison situation. The prisoners were kept in the makeshift prison set up in the basement of the Psychology Department, where the guards were responsible for ensuring the inmates followed prison regulations. The participants were screened to guarantee they had no mental or physical problems that may have influenced their behavior.

The experiment concluded that it is possible to change the behavior of individuals when placed in groups, even when they are not aware they are being observed. The study showed how quickly people will conform to expected social roles and how easily ‘ordinary’ people can be transformed from ‘good’ to ‘evil.’ Both the prisoners and guards revealed stereotypical characteristics associated with correctional officers; the prisoners became emotionally unstable and submissive, whilst the guards became hostile and authoritative.

1.3. Criticisms

Philip Zimbardo’s experiment, the Stanford Prison Experiment, is like a dark mirror reflecting our society’s innermost fears. In 1971, Zimbardo conducted an experiment in which college students were randomly assigned to be either prisoners or guards in a simulated prison environment. The results of this study showed that people could quickly adapt to roles and lose their sense of morality when placed in certain situations.

The impact of the Stanford Prison Experiment has been far-reaching; it has been used as evidence for why prisons are so dangerous and how they can lead to psychological damage among inmates. It also serves as a reminder that power dynamics between individuals can have serious consequences if not monitored closely.

Critics have argued that the ethical practices employed by Zimbardo during his experiment were questionable at best, with some participants experiencing extreme distress due to their role-playing experience. Despite these criticisms, many believe that the experiment still provides valuable insight into human behavior and psychology today. Personifying its lessons, we could say that the Stanford Prison Experiment speaks volumes about how easily our moral compass can become distorted when faced with authority figures or oppressive environments.

The Asch Conformity Experiment, 1951

2.1. overview.

The Asch Conformity Experiment, also known as the “Asch Line Study,” was a series of experiments conducted by psychologist Solomon Asch in 1951 to test how people tend to conform to social pressures. The study was composed of two groups: one consisting of actual participants (the control group) and the other including actors (the confederates).

During the experiment, the participants were asked to view a line on one board and then match it to one of three lines on another board with their own judgment. Initially, the group was given correct answers; however, after a few attempts, the actors began to give wrong answers intentionally to observe how the participant would respond.

2.2. Results

The results showed that 75% of the participants conformed to the incorrect majority opinion given by the confederate group—even when it obviously contradicted their own senses. In addition, the control group with only real subjects produced a much lower rate of conformity, with less than 1% ever selecting the incorrect answer. This demonstrated that it was not the difficulty of the task but rather the presence of an influential social group that caused the majority of participants to deny their own thoughts in order to fit in with the others.

2.3. Criticisms

Critics have argued that the experiment was not diverse enough since it mainly used college-aged men as its sample population. Additionally, because the experiment did not include females, it has been suggested that the results of the cave experiment cannot be generalized to all genders.

Furthermore, critics have argued that the experimental design lacked a true measure of real-life social pressure since the actors and real participants knew the situation was artificial. Despite these criticisms, the Asch experiment remains one of the most important social psychology studies in history, and its core message about the power of conformity to influence opinions and behavior continues to be studied and discussed today.

We tackled the topic of conformity in our article about social influence .

The Bobo Doll Experiment, 1961

3.1. overview.

The Bobo Doll experiment was a series of experiments conducted by psychologist Albert Bandura between 1961 and 1963 at Stanford University, aimed at studying the extent to which human behavior is based on social imitation rather than inherited genetic factors.

Three groups of 24 participants each, aged from 3 to 6 years old, were chosen for the experiment – a control group (with no interaction with any adults), an aggressive group (observing an adult behaving aggressively towards the doll), and a passive group (observing a more passive adult playing with the doll). The results of the studies were a strong indication that children were strongly influenced by watching other people’s behavior and imitated it afterward in their own behavior.

3.2. Results

The study found that the children in the aggressive and passive groups were significantly more likely to behave aggressively towards the bobo doll than those in the control group, even though the latter had not been exposed to any type of model behavior. When it came to gender differences, boys showed more aggressive behavior when exposed to the aggressive behavior of male models, while girls showed similar findings, albeit less drastic.

Moreover, the study also contained a memory test during which wrong answers were punished with electric shocks; here, it appeared as if the individual completing the test was affected by the electric shocks, suggesting that authority figures can greatly influence behavior, even if not intentionally. Finally, the study also showed that when urged to continue with the experience even after protests from the individual receiving electric shocks, they complied with the requests, highlighting the power of authority within social situations.

3.3. Criticisms

Although the experiment raised widely accepted as evidence for the hypothesis that individuals learn behavior by observing others, the Bobo Doll experiment has been criticized in recent years. One key point of criticism is that Bandura’s research neglected to look at positive modeling – for example, modeling of altruism or helpful behavior, instead focusing solely on aggression.

Additionally, some have argued that, due to its relatively small sample size and laboratory-based approach, the study failed to take into account real-life influences, such as environmental variables, which would have provided additional context. Despite these criticisms, the Bobo Doll experiment remains one of the most famous studies in psychology, providing significant evidence for the importance of social learning theory in understanding human behavior.

The Milgram Experiment, 1963

4.1. overview.

The Milgram Experiment was a famous social psychology experiment and experiment conducted by Stanley Milgram in the 1960s. Its aim was to test people’s obedience to authority. The study examined how far people would go when an authority figure instructed them to perform acts that conflicted with their morals.

Specifically, it sought to find out if non-Nazi populations, such as those from the United States, would follow orders to harm other persons. One of the motivations for this investigation was the results of World War II, during which Nazi leader Adolf Eichmann was able to use “I was only following orders” as a legal defense at the Nuremberg trials.

4.2. Results

The experiment was conducted at Yale University in 1961 and included unsuspecting participants who were told that the study was about memory. Participants believed they were participating in a study where they would be required to act as teachers while an unsuspecting confederate (learned) was on the other side of the wall. Their task was to ask questions to the learner, and if they received a wrong answer, press a button administering shock, ranging from 15 volts to 450 volts.

The results showed that despite protests and cries from the learner, 63% of the participants continued pressing the switch. Milgram’s experiment revealed that human beings are conditioned to obey authority figures, even when going against their natural moral code.

4.3. Criticisms

Despite its significance, the Milgram Experiment has been heavily criticized over the years, and some have argued that the study violated ethical standards. The argument is that causing psychological and emotional distress to unwitting volunteers is wrong. Other critics have argued that the role reversals or changes in lab settings would yield different outcomes and should have been considered.

In response to these criticisms, some scientists have suggested controversial experiments by reducing the voltage administered to the learner or conducting newer versions of the experiment in naturalistic settings. In addition, the way modern studies measure obedience is greatly different – contemporary research focuses on motives and reactions participants have after the experiment. These proposed changes would enable researchers to look into extraneous factors influencing obedience versus harm caused to participants.

The Halo Effect Experiment, 1977

5.1. overview.

The halo effect is commonly defined as the phenomenon in which a positive evaluation of one trait extends to an overall perception of an individual. This cognitive bias has been observed by social psychologists for over a century, beginning with psychologist Edward Thorndike’s studies regarding commanding officers in the military.

The halo effect is also known as the “what is beautiful is good” principle or the “physical attractiveness stereotype.” This phenomenon has had a lasting impact on our evaluation and judgment of others. Additionally, the term “halo effect” was named after its likeness to that of the halo painted above the heads of saints and holy figures in religious art, generally regarded as symbols of moral goodness.

To investigate this phenomenon further, Nisbett and Wilson conducted an experiment in 1977 at the University of Michigan. As research participants, they recruited college students who were asked to watch a pre-recorded psychology instructor tape with two different attitudes—one likable and another unlikable. After watching the videotapes, they filled in a questionnaire that asked them to rate the lecturer’s physical appearance, mannerisms, and accent on an 8-point scale ranging from “like extremely” to “dislike extremely.”

Nisbett and Wilson’s study showed that despite the lecturers having the same mannerisms and accents, the respondents rated the lecturer more favorably if their attitude projected a likable demeanor. Moreover, Nisbett and Wilson discovered that people are unaware when the halo effect phenomenon occurs; they inferred that the respondents relied on their initial impression of the lecturer without being aware that it influenced their subsequent assessment. In total, 278 college students participated in the study.

5.2. Results

The results of this study showed that the ratings of the lecturer responded differently depending on his behavior—those who saw him adopt a likable demeanor in the video gave him higher ratings than those who saw him act in an unlikable manner. Furthermore, those who rated the lecturer highly were more likely to believe that he was intelligent, hardworking, kind, and humorous. This suggests that the halo effect can lead people to make inaccurate assumptions about someone based solely on their appearance or behavior.

Moreover, an updated study on the halo effect also suggests that a negative assessment of certain traits can similarly affect subsequent perceptions. For instance, if someone didn’t like the instructor’s physical appearance, they are more likely to rate him as unintelligent and lazy. This provides evidence that negative feelings about one characteristic can extend to an individual’s other features.

5.3. Criticisms

Despite its analytical contributions to the field, some scholars have questioned Nisbett and Wilson’s use of college students as the research participants in the study due to their limited exposure to the concept at hand. Additionally, since the focus of this experiment utilized only pre-recorded videos, there is also criticism of the limitation in the accuracy of facial expressions and vocal intonations. However, this study does provide evidence that people may rely on initial impressions when making assessments, resulting in cognitive bias and inaccurate judgments.

The False Consensus Effect Experiment, 1974

6.1. overview.

The False Consensus Effect Experiment was conducted in 1974 by Professor Lee Ross, then at Stanford University. The experiment focused on how people can form a “false consensus” about the beliefs and preferences of others. Specifically, it asked participants to read situations with two alternative responses and predict which one other people would choose. In the study, most subjects overestimated the likelihood that others would do the same thing as them, even when the situation was hypothetical and there was no real data to indicate what choice the majority of people might make. Furthermore, researchers found that the anticipation of a false consensus could lead people to display negative predictions about the personalities of those who did not share their choice.

6.2. Results

The results of Lee Ross’s experiment demonstrated the false consensus bias – the tendency to overestimate the extent to which others agree with one’s own beliefs and behaviors. He and his colleagues also conducted experiments in the late 1970s to demonstrate how this bias operates in estimating other people’s behaviors and causes. For example, participants chose a resolution to an imagined conflict, then estimated how many others would choose the same.

In another experiment, students were asked to carry a sign that read “eat at joe’s” to measure how many other people agreed with the sign. Those who agreed believed the majority of people would also agree; those who refused believed the majority would refuse. This experiment showed the false consensus effect – we tend to believe the majority of people agree with us and act the same way.

6.3. Criticisms

The false consensus effect is like a mirage in the desert, appearing to be something it’s not. It occurs when people overestimate how much other people agree with them. This bias can lead to an inaccurate perception of reality and cause individuals to make decisions based on false assumptions. The false consensus effect is most likely to occur when someone has strong beliefs or opinions about a particular topic and assumes that others share their views.

The Chameleon Effect Experiment, 1990

7.1. overview.

The Chameleon Effect is a phenomenon of unintentional mirroring, which was observed and studied for the first time in 1939 at the University of Iowa by Dr. Wendell Johnson. It involves someone mimicking another’s body posture, hand gestures, or even speaking accents without realizing it. In the 1990s, researchers Tanya Chartrand and John Bargh conducted follow-up experiments to further study this effect, which would be known as the “Chameleon Effect.”

7.2. Results

During their experiment, Chartrand and Bargh secretly mimicked the actions and behaviors of some test subjects during their conversations and monitored the responses. Those that were mimicked found the researchers more likable compared to those not mimicked. The results point to how people often subconsciously respond to others even if they weren’t consciously aware of the imitating behavior.

7.3. Criticisms

Despite being a popular explanation for why people tend to mirror each other’s behavior, the Chameleon Effect has been criticized by some. These criticisms mostly come from the idea that the phenomenon could potentially involve manipulation as well as desensitizing people to be more vulnerable to conformity and impressions. Additionally, some suggest there may be other reasons why people might mirror each other other than the Chameleon Effect itself, such as insecurity or politeness.

The Diffusion of Responsibility Experiment, 1968

8.1. overview.

The diffusion of responsibility experiment, conducted in 1968 at Stanford University, is an iconic social psychology experiment. It is studied to understand the bystander effect, a phenomenon in which people are more reluctant to express helpfulness or give aid if other bystanders are present.

Stanley Milgram and John Darley conducted the experiment to analyze how the presence of others could influence helping behaviors in kids. The study was also connected to concepts from Lev Vygotsky’s theory referring to emotional role-taking and group cohesiveness when observing the behavior of other members in a particular situation.

In the study, 600 children between the ages of four to six were tested. Each child was presented with one marshmallow, and they were promised to receive a second one if it still remained on the table after 15 minutes.

The results showed that only one-third of the children had delayed their gratification long enough to obtain the second marshmallow. Follow-up studies demonstrated that those children who managed to delay gratification and obtain the second marshmallow had higher SAT scores and were found to be more competent than their peers who could not wait and ate the marshmallow immediately.

8.2. Results

The results of the diffusion of responsibility experiment in 1968 proved to be true to an extent. Its findings added significantly to defining the bystander effect and the effects of the presence of other people, which may inhibit helpers’ reactions to those in need. The research showed that the number of bystanders could have a profound effect on one’s decision on whether to act or to remain inactive. This study takes into account the psychological phenomenon known as diffusion of responsibility which partially explains this inhibition of helping behavior.

8.3. Criticisms

Although the diffusion of responsibility experiment has contributed greatly to our understanding of the bystander effect, there is some criticism surrounding the validity and applicability of the experiment change in the setting in which it was conducted. Namely, there is some concern around the age of the participants, as well as the amount of time provided for the test, both of which may have had an influence on the outcome. In addition, since the experiment was conducted in 1972, there have been numerous changes to society and culture that may not have been taken into account by the authors at the time, leaving some questions as to its usefulness in current situations.

The Cognitive Dissonance Experiment, 1957

Leon Festinger’s Cognitive Dissonance Experiment of 1957 addresses the mental discomfort experienced when trying to hold two conflicting beliefs. The experiment sought to identify how this dissonance is resolved by people and to gain further insight into our thoughts and behaviors.

Stanley Schachter and Jerome E. Singer conducted the experiment with the intention of testing the cognitive theory of emotional arousal. They injected participants with epinephrine, a hormone that can produce side effects– both physical and psychological – such as increased heart rate, faster breathing, and an elevation in blood pressure.

The study featured a confederate who acted either in one of two ways: they were either pleasant or unpleasant. As knowledge of the injection’s side effects became aware to the participants, their emotions shifted accordingly. This revealed that dissonance leads to emotional arousal in individuals, leading them to act in agreement with emotion-triggering cognition.

In light of its results, critics have since made a note of the implausibility of Schachter and Singer’s study, claiming that it does little to address the complexities of the cognitive dissonance theory. By comparison, Leon Festinger’s cognitive dissonance experiment assumes that everyone holds many different cognitions about the world. It then examines what happens when those cognitions do not fit together adequately. Discrepancies are accepted if an event or occurrence makes sense; if not, these discrepancies lead to a state of tension or dissonance.

Interested readers may refer to festive ger’s 1959 article, “Cognitive Dissonance,” for a more in-depth exploration of the experiment’s results and implications. The study remains a classic social psychology experiment, illustrating how we reconcile the conflicts created by existing contradictory beliefs.

The 10 most influential social psychology experiments in history can all be summarized by their contribution to the development of our understanding of human behavior. From Milgram’s famous study revealing our willingness to obey authority figures, to Bandura’s Bobo Doll Experiment establishing the power of aggression and imitation, to Nisbett and Wilson’s Halo Effect Experiment controlling biases towards physical attractiveness, these studies provide insights into the power of group dynamics, social pressures, and cognitive bias that continue to inform and impact modern society today.

Learning about these classic social psychology experiments also encourages us to question our assumptions, explore alternative perspectives, and strive for greater understanding and acceptance. Whether by examining the limitations of data collection or the ethical implications of research methods, these landmark studies have built our knowledge base and served as a reminder of the importance of respect and empathy.

In conclusion, the 10 most influential social psychology experiments listed reflect an inspiring effort to better understand human behavior and engage in much-needed conversations around this fascinating field.

Frequently Asked Questions

What were the initial experiments in social psychology.

Norman Triplett’s 1898 experiment is credited with being the first social psychology experiment. He examined the effects of competition on a simple task – winding hempen string – and found that people performed better when in the presence of others than when alone. His findings ushered in an exciting new field of research into how people are both influenced by, and affect, the social world around them.

Why are experiments are used in social psychology?

Experiments provide valuable insight into human behavior and allow for cause and effect relationships to be better understood. They are an essential tool conducting research in social psychology, allowing the researcher to observe how individuals respond in different situational contexts. Experimentation allows us to answer important questions about social behavior, making it an invaluable research method.

What are social psychology topics?

Social psychology explores the fascinating ways that people interact with each other, from understanding why prejudicial behavior occurs to analyzing why some people have a greater degree of influence over human behaviors than others. Social psychology has played a major role in helping us understand human behavior. It has made invaluable contributions through its research on various topics like prejudice and discrimination, gender, culture, social influence, interpersonal relations, group behavior, aggression etc.

What is an example of a social experiment?

An example of a social experiment is Stanley Milgram’s obedience experiment conducted in 1963 which tested human subjects’ willingness to obey orders regardless of the outcomes. This controversial experiment was conducted in order to understand how far people would go to follow orders from authority figures, even if it meant inflicting pain on another person.

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What was the social experiment of the 60s?

The Social Experiment of the 1960s was the Milgram experiment, conducted by Yale University psychologist Stanley Milgram. It tested participants’ willingness to obey authority when asked to do something that conflicted with their own moral values. The experiment yielded powerful insights into human behavior and the power of authority, making it one of the most influential experiments of its time.

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IResearchNet

Social Psychology Experiments

Social psychology experiments have played a pivotal role in unraveling the intricate tapestry of human behavior, cognition, and emotions within the social context. These experiments represent more than just scientific inquiries; they serve as windows into the fundamental aspects of human nature and the ways in which we interact with others. This article delves into a selection of famous experiments in social psychology, each a milestone in understanding the complexities of human social behavior.

Thesis Statement: The significance of these famous experiments extends far beyond the realm of academia, shaping our understanding of conformity, obedience, group dynamics, morality, and the subconscious biases that influence our decisions and actions. Through these groundbreaking studies, we gain valuable insights into the human condition, prompting us to question, explore, and reflect upon the intricate web of social interactions that define our lives.

Famous Experiments in Social Psychology

The Bennington College study was conducted by sociologist Theodore Newcomb from 1935 until 1939. The study examined the attitudes of students attending the then all-female Bennington College early in the college’s history; indeed, the study began during the first year that the college had a senior class.

Solomon Asch’s Conformity experiments in the 1950s starkly demonstrated the power of conformity on people’s estimation of the length of lines. On over a third of the trials, participants conformed to the majority, even though the majority judgment was clearly wrong. Seventy-five percent of the participants conformed at least once during the experiment.

In Muzafer Sherif ’s Robbers Cave experiment (1954) boys were divided into two competing groups to explore how much hostility and aggression would emerge. It is also known as realistic group conflict theory, because the intergroup conflict was induced through competition over resources.

Leon Festinger’s Cognitive Dissonance experiment subjects were asked to perform a boring task. They were divided into two groups and given two different pay scales. At the end of the study, participants who were paid $1 to say that they enjoyed the task and another group of participants were paid $20 to say the same lie. The first group ($1) would later believe that they like the task better than the second group ($20). People justified the lie by changing their previously unfavorable attitudes about the task (Festinger and Carlsmith 1959).

Stanley Milgram’s Obedience to Authority experiment has shown how far people would go to obey an authority figure. Following the events of the Holocaust in World War II Stanley Milgram’s experiments of the 1960s/1970s showed that normal American citizens were capable of following orders to the point of causing extreme suffering in an innocent human being.

Albert Bandura’s Bobo Doll experiment has demonstrated how aggression is learned by imitation (Bandura et al. 1961). Bandura’s experimental work was one of the first studies in a long line of research showing how exposure to media violence leads to aggressive behavior in the observers.

In Philip Zimbardo’s Stanford Prison experiment a simulated exercise between student prisoners and guards showed how far people would follow an adopted role. This was an important demonstration of the power of the immediate social situation, and its capacity to overwhelm normal personality traits (Haney et al. 1973).

The Milgram Experiment

Background and Context

The Milgram Experiment, conducted by psychologist Stanley Milgram in the early 1960s, arose in a climate of post-World War II questions about obedience, authority, and moral responsibility. Inspired by the Nuremberg Trials and the revelation of the atrocities committed by Nazi personnel who claimed to be “just following orders,” Milgram sought to explore the extent to which individuals would obey authority figures, even when it conflicted with their own moral beliefs.

Experiment Setup and Procedure

The experiment involved three key roles: the experimenter (authority figure), the teacher (participant), and the learner (an actor). Participants believed they were assisting in a study examining the effects of punishment on learning. The teacher was instructed to administer increasingly severe electric shocks to the learner for incorrect responses in a word-pair memory test. Unbeknownst to the teacher, the learner did not actually receive shocks, but their responses were scripted to simulate distress and pain.

Ethical Concerns and Criticisms

The Milgram Experiment has been widely criticized for its ethical implications. Participants were exposed to significant psychological stress and believed they were causing harm to another person, potentially leading to long-lasting emotional trauma. Critics argue that the experiment lacked proper informed consent, and the debriefing process may not have been sufficient to alleviate the distress experienced by participants.

Major Findings and Their Impact

The Milgram Experiment revealed astonishing results. Contrary to expectations, a significant proportion of participants, under the pressure of the authority figure’s commands, continued to administer shocks up to potentially lethal levels, even when they were aware of the learner’s distress. This demonstrated the profound influence of authority figures on individual behavior.

The study shed light on the psychology of obedience and the potential for ordinary people to engage in harmful actions under the guise of following orders. Milgram’s findings raised ethical and moral questions about blind obedience and individual responsibility in the face of authority.

The Stanford Prison Experiment

The Stanford Prison Experiment, conducted by psychologist Philip Zimbardo in 1971, stands as one of the most notorious and influential studies in social psychology. Emerging during a tumultuous period in American history marked by social unrest and the questioning of authority, the experiment sought to investigate the psychological dynamics of power, authority, and the consequences of perceived roles within a simulated prison environment.

Description of the Experiment

The experiment involved the transformation of the basement of Stanford University’s psychology department into a mock prison. Volunteers were randomly assigned to play the roles of either guards or prisoners in a simulated prison environment. The participants quickly adapted to their roles, with guards displaying authoritarian behaviors, and prisoners experiencing psychological distress and rebellion. The study was originally intended to last two weeks but was terminated after only six days due to the alarming and unethical behaviors exhibited by both guards and prisoners.

Ethical Controversies

The Stanford Prison Experiment has been mired in ethical controversies. Critics argue that the psychological harm inflicted upon participants was severe, and the lack of proper oversight allowed the study to veer into dangerous territory. Questions have also been raised regarding the informed consent process, as participants were not fully aware of the potential psychological consequences of their involvement.

Key Findings and Implications

Despite its ethical shortcomings, the Stanford Prison Experiment yielded valuable insights into the malleability of human behavior in response to situational factors. It demonstrated how ordinary individuals could quickly adopt abusive and authoritarian roles when placed in positions of power. The study underscored the importance of ethical considerations in psychological research and prompted discussions about the responsibility of researchers to ensure the well-being of participants.

The implications of the study extend beyond academia, offering a cautionary tale about the potential for abuses of power and authority. It has influenced discussions on ethics in research, the psychology of group dynamics, and the understanding of how situational factors can shape behavior.

The Asch Conformity Experiment

Introduction and Historical Context

The Asch Conformity Experiment, conducted by Solomon Asch in the 1950s, remains a seminal study in the field of social psychology. Emerging in the post-World War II era, this experiment aimed to investigate the extent to which individuals conform to group norms and the impact of social pressure on individual decision-making.

Experiment Design and Methodology

In the Asch Conformity Experiment, participants were placed in a group of individuals, with the participant being the only true subject. The group was presented with a simple perceptual task: comparing the length of lines. Participants were asked to state which of several lines was of equal length to a reference line. Unknown to the participant, the other group members were confederates who had been instructed to give incorrect answers in some trials.

During the critical trials, the confederates deliberately provided incorrect answers that contradicted the obvious correct response. The participant, seated at the end of the row, faced the dilemma of whether to conform to the group’s incorrect consensus or assert their own judgment.

Conformity Results and Interpretations

The results of the Asch Conformity Experiment were striking. Despite the obvious correctness of their own judgments, participants frequently succumbed to group pressure and provided incorrect responses to match the consensus of the group. On average, about one-third of participants conformed to the group’s incorrect answers in the face of social pressure.

Asch’s findings underscored the potent influence of social conformity and the willingness of individuals to abandon their own perceptions and judgment in favor of group consensus. He also identified several factors that influenced the likelihood of conformity, such as the size of the majority and the unanimity of the group.

Influence on Social Psychology and Beyond

The Asch Conformity Experiment significantly impacted social psychology by highlighting the powerful role of social influence on human behavior. It prompted further research into group dynamics, conformity, and the psychology of social norms. Asch’s work laid the foundation for studies on topics such as groupthink, normative influence, and the conditions under which individuals are more likely to resist social pressure.

Beyond social psychology, the experiment has practical implications for understanding how conformity operates in everyday life, from peer pressure among adolescents to decision-making in organizations. The study has also been instrumental in discussions about individual autonomy and the tension between conforming to societal expectations and asserting one’s independent judgment.

The Asch Conformity Experiment remains a timeless exploration of the human propensity to conform and the psychological mechanisms at play when individuals navigate the tension between individuality and social cohesion.

The Robbers Cave Experiment

Background and Purpose of the Study

The Robbers Cave Experiment, conducted by psychologist Muzafer Sherif and his colleagues in 1954, was designed to investigate intergroup conflict and cooperation among children. The study emerged during a time when Cold War tensions and conflicts between nations were a prominent backdrop, prompting Sherif to explore the dynamics of group conflict on a smaller scale.

The central purpose of the study was to understand how group identities, competition, and cooperation could influence the attitudes and behaviors of individuals within groups and across groups. It sought to shed light on the origins of intergroup hostility and the potential for reconciliation.

Experimental Design and Procedures

The study took place at Robbers Cave State Park in Oklahoma and involved two phases.

• Group Formation : In the first phase, a group of 22 boys was divided into two groups, the Rattlers and the Eagles, with no prior knowledge of each other. The boys formed strong group identities through team-building activities and bonding experiences.
• Intergroup Competition : In the second phase, the two groups were introduced to each other and engaged in competitive activities, such as sports and contests, where rivalries quickly developed. The competition intensified intergroup conflicts, leading to name-calling, vandalism, and hostility.
• Intervention and Cooperation : To address the escalating conflict, the researchers initiated activities that required the groups to collaborate, such as solving common problems and working together towards common goals. These cooperative experiences aimed to reduce intergroup tensions.

Notable Findings and Insights on Intergroup Conflict

The Robbers Cave Experiment yielded several important findings:

• Intergroup conflict emerged swiftly when groups were formed and exposed to competition, even among previously unacquainted individuals.
• The competition exacerbated stereotypes and prejudices between the groups.
• Cooperation between groups, when introduced strategically, had the potential to reduce hostilities and foster intergroup harmony.
• The study illustrated the role of superordinate goals (common objectives that transcended group boundaries) in promoting cooperation and reducing conflict.

Practical Applications and Contributions

The Robbers Cave Experiment has had lasting implications in the fields of social psychology and conflict resolution. It provided valuable insights into the dynamics of intergroup conflict and cooperation, shedding light on the processes by which hostility between groups can be both fueled and mitigated.

The concept of superordinate goals, derived from the study, has been widely applied in conflict resolution efforts. By identifying shared objectives that require collaboration across group lines, individuals and societies have been able to bridge divides and work together toward common aims. The study’s lessons have informed strategies for reducing prejudice, improving intergroup relations, and fostering peace in various contexts, including education, organizational management, and international diplomacy.

The Robbers Cave Experiment remains a classic illustration of how group identities and competition can lead to conflict, while also highlighting the potential for cooperation and reconciliation when shared goals and positive intergroup interactions are promoted.

The Zimbardo Stanford Prison Experiment

Overview of the Experiment

The Zimbardo Stanford Prison Experiment, conducted by psychologist Philip Zimbardo in 1971, is a widely recognized and controversial study in the realm of social psychology. The experiment was designed to investigate the psychological effects of perceived power and authority within a simulated prison environment.

In this study, participants were randomly assigned to play the roles of either guards or prisoners in a mock prison set up in the basement of Stanford University’s psychology department. The experiment aimed to explore how individuals, when placed in positions of power or vulnerability, would react and adapt to their roles.

Ethical Considerations and Criticisms

The Zimbardo Stanford Prison Experiment has been marred by significant ethical concerns and criticisms. The study generated intense psychological distress among participants, with the guards exhibiting abusive and authoritarian behaviors, and the prisoners experiencing emotional and psychological harm. The experiment’s duration, initially planned for two weeks, was terminated after only six days due to the extreme and unethical behaviors displayed by participants.

Critics argue that the study lacked proper informed consent, as participants were not fully aware of the potential psychological consequences of their involvement. The absence of proper oversight and safeguards to protect the well-being of participants has been a focal point of ethical critique.

Psychological Effects on Participants

The Zimbardo Stanford Prison Experiment had profound psychological effects on its participants. Guards, assigned to positions of power, quickly adopted authoritarian roles, displaying abusive behaviors toward the prisoners. Prisoners, on the other hand, experienced distress, humiliation, and a sense of powerlessness.

The psychological effects on participants were so severe that the study was terminated prematurely to prevent further harm. Post-experiment interviews revealed that some participants struggled to differentiate between their roles and their true identities, emphasizing the significant impact of situational factors on individual behavior.

Enduring Influence on Social Psychology

Despite its ethical controversies, the Zimbardo Stanford Prison Experiment had a lasting influence on the field of social psychology. It highlighted the malleability of human behavior in response to situational factors and the potential for ordinary individuals to engage in abusive actions when placed in positions of authority.

The study contributed to discussions on ethics in research and the responsibility of researchers to prioritize the well-being of participants. It also prompted further investigations into the psychology of power, authority, and obedience, leading to a deeper understanding of the complexities of human behavior within social contexts.

The Zimbardo Stanford Prison Experiment remains a cautionary tale in the annals of psychology, reminding researchers of the ethical imperative to protect participants and the enduring influence of situational factors on human behavior.

The Little Albert Experiment

Introduction to the Study

The Little Albert Experiment is a classic and ethically controversial study conducted by behaviorist John B. Watson and his graduate student Rosalie Rayner in 1920. The experiment aimed to investigate the process of classical conditioning, particularly the acquisition of phobias and emotional responses in humans.

The study is named after its subject, a 9-month-old boy known as “Little Albert.” It remains a notable case study in the field of psychology due to its ethical concerns and contributions to the understanding of learned behaviors.

Experiment Details and Ethical Concerns

In the Little Albert Experiment, Little Albert was exposed to a white rat, a rabbit, a dog, a monkey, and other stimuli. Initially, he displayed no fear or aversion to these objects. However, Watson and Rayner sought to condition an emotional response in Little Albert by pairing the presentation of these stimuli with a loud, frightening noise (produced by striking a suspended steel bar with a hammer). As a result of this pairing, Little Albert began to exhibit fear and distress in response to the previously neutral stimuli, particularly the white rat.

The ethical concerns surrounding this experiment are significant. Little Albert was not provided with informed consent, and his emotional well-being was disregarded. The study also lacked proper debriefing, and the long-term consequences of Little Albert’s conditioning were not addressed. The ethical standards of today would prohibit such a study from being conducted.

Conditioning Process and Long-Term Implications

The Little Albert Experiment demonstrated the principles of classical conditioning in humans. It illustrated how conditioned emotional responses, such as fear and anxiety, could be acquired through association with previously neutral stimuli. In this case, Little Albert learned to fear the white rat because it had been consistently paired with a loud, frightening noise.

The long-term implications of the study are less clear due to a lack of follow-up research on Little Albert. It remains unknown whether his conditioned fears persisted or how they may have impacted his later development. The study’s ethical shortcomings prevent a comprehensive assessment of its long-term effects.

Contemporary Perspectives on the Study

The Little Albert Experiment is viewed with skepticism and ethical concern from contemporary perspectives. It serves as a reminder of the importance of informed consent, debriefing, and the ethical treatment of research participants in psychological research. Ethical standards in research have evolved significantly since the time of the experiment, emphasizing the need to prioritize the well-being and rights of participants.

While the Little Albert Experiment contributed to the understanding of classical conditioning, it also serves as a cautionary tale about the ethical boundaries of research and the potential consequences of disregarding the psychological well-being of participants. Modern research ethics prioritize the protection and respect of individuals involved in psychological studies, ensuring that similar experiments would not be conducted today.

The Blue-Eyes/Brown-Eyes Exercise

Historical Context and Significance

The Blue-Eyes/Brown-Eyes Exercise is a landmark social experiment conducted by educator and activist Jane Elliott in the late 1960s. The experiment was born out of the civil rights movement in the United States and sought to address issues of racism, discrimination, and prejudice. Against the backdrop of racial tensions and the struggle for civil rights, Elliott designed the exercise to provide a firsthand experience of the effects of discrimination.

Experiment Design and Outcomes

In the Blue-Eyes/Brown-Eyes Exercise, Elliott divided her third-grade students into two groups based on eye color, designating one group as “superior” (those with blue eyes) and the other as “inferior” (those with brown eyes). Over the course of the exercise, Elliott systematically treated the two groups differently, providing privileges to the superior group while subjecting the inferior group to discrimination and negative stereotypes.

The results of the experiment were profound. Children in the inferior group quickly internalized their assigned role and began to exhibit lower self-esteem, diminished academic performance, and a range of negative emotional responses. On the other hand, those in the superior group displayed increased arrogance and a sense of entitlement.

Elliott conducted the exercise over multiple days, reversing the roles on the second day to provide a taste of both sides of discrimination. The exercise aimed to create empathy and understanding among participants by allowing them to personally experience the emotional and psychological impact of discrimination.

Broader Societal Impact and Implications

The Blue-Eyes/Brown-Eyes Exercise had a significant societal impact. It garnered attention in the media and brought issues of racism and discrimination to the forefront of public consciousness. Elliott’s work challenged prevailing beliefs about the nature of prejudice and discrimination, highlighting the role of societal conditioning in perpetuating such attitudes.

The exercise also emphasized the importance of empathy and perspective-taking in combatting racism and prejudice. By allowing participants to experience discrimination firsthand, Elliott aimed to foster greater empathy and understanding among individuals of different racial backgrounds.

Experimentation in Social Psychology

Experimentation definition.

Experimentation, in its simplest form, is a research method used to investigate the presence or absence of a causal relationship between two variables. This method involves systematically manipulating one variable, known as the independent variable, and then assessing the impact or effect of this manipulation on another variable, referred to as the dependent variable. Through experimentation, researchers aim to discern whether changes in the independent variable cause changes in the dependent variable, providing insights into causal relationships within a given phenomenon or context. This systematic and controlled approach allows for rigorous testing of hypotheses and the establishment of cause-and-effect relationships in scientific inquiry.

Importance and Consequences of Experiments

The importance and consequences of experiments in research are closely tied to their unique ability to establish causal relationships. Here are key features of experiments that facilitate the ability to draw causal conclusions and their implications:

• Establishing Causality: Experiments are highly valuable because they allow researchers to make statements about causality. By systematically manipulating the independent variable and assessing its impact on the dependent variable, researchers can infer that changes in the independent variable cause changes in the dependent variable. This cause-and-effect relationship is central to scientific inquiry and helps uncover the mechanisms underlying various phenomena.
• Directionality of Relationship: Experiments provide a clear temporal sequence where changes in the independent variable precede the assessment of the dependent variable. This temporal order is crucial for determining the directionality of the relationship between variables. In causal relationships, the cause must precede the effect. Experiments ensure that this criterion is met, enabling researchers to infer the causal direction.
• Random Assignment: In experiments, participants are randomly assigned to different experimental groups. Random assignment ensures that each participant has an equal chance of being assigned to any experimental condition, creating equivalent groups at the outset. This eliminates the possibility that pre-existing differences between participants could account for observed differences in the dependent variable. Random assignment strengthens the validity of causal claims by minimizing confounding variables.
• Isolation of Effects: Experiments enable researchers to isolate the effects of the independent variable by controlling all other aspects of the environment. This control ensures that all participants have a similar experience, except for the experimental manipulation. By eliminating extraneous variables, researchers can attribute any observed differences in the dependent variable solely to the independent variable. This isolation of effects enhances the internal validity of the study.

In summary, experiments are a powerful research method that allows for the establishment of causal relationships in scientific inquiry. Their ability to establish causality, ensure temporal precedence, employ random assignment, and isolate the effects of the independent variable makes experiments a cornerstone of empirical research. Researchers must adhere to these principles to draw valid and reliable conclusions about the causal relationships between variables, advancing our understanding of various phenomena in social psychology and other fields.

Some scholars have questioned the utility of experimentation, noting that the experiments which researchers design sometimes do not resemble the circumstances that people encounter in their everyday lives. However, experimentation is the only research method that allows one to definitively establish the existence of a causal relationship between two or more variables.

References:

• Goodwin, C. J. (2003). Research methods in psychology: Methods and design. New York: Wiley.
• Pelham, B. W. (1999). Conducting research in psychology: Measuring the weight of smoke. Pacific Grove,CA: Brooks/Cole.

# 5 Famous Social Psychology Experiments

There are countless social psychology experiments that have been influential. Here, we highlight five powerful experiments in social psychology that have shaped the development of the field.

# 1. Solomon Asch’s Experiments on Conformity

Solomon Asch carried out a series of psychological tests known as the Asch Conformity Experiments in the 1950s to find out how much social pressure from the majority group could persuade a person to conform. Asch’s experimental hypothesis was centered around how people gave in to peer pressure and whether they would disregard their own opinions in order to fit in with the group. The experiment summary of the Asch conformity studies is that several lines with different heights are presented and the participant is challenged by the confederate’s answers to either agree or disagree.

The Asch experiment's basic design comprised a subject and a cohort of accomplices. The participants were informed that they would be performing a visual perception task in which they would need to match a given line's length to one of three comparison lines.

Out of all the participants in each group, only one was truly ‘naïve’; the others were ‘confederates’ who were told to provide false answers on purpose for specific trials. Thus, the ‘naive’ participant would be challenged by the ‘confederates’ who provided wrong answers. This would essentially place the ‘naive’ participant in a challenging position to be in.

An example of the experimental procedure from Solomon Asch’s experiment on conformity in 1955. There are 6 confederates pictures and the 1 real participant, sitting in the second to last seat, who are looking at the trial stimuli at the front of the room. Image copyright: Cara Flanagan.

Throughout the trials, the confederates would intentionally select the incorrect response. The crucial query was whether the ‘naive’ participant would follow their own accurate assessment or adhere to the false majority opinion. The results and findings demonstrated that even in cases where the right response was evident, a sizable portion of the ‘naive’ participants would agree with the confederate group's inaccurate responses.

The degree of conformity was influenced by several factors:

• Group Size: Up to a certain point, conformity grew in proportion to the size of the majority. The rate of conformity did not significantly increase after a certain number of confederates.
• Unanimity: A participant was far less likely to comply if even one other person in the group provided the right response. The pressure to fit in was significantly lessened when there was a dissident voice.
• Task Difficulty: Participants found it more difficult to trust their own judgment when the task was more ambiguous or difficult, ie. when the comparison lines were more similar in size, leading to an increase in conformity.
• Response Type - Public vs. Private: When participants were required to provide their answers in public, they were more likely to comply, as opposed to when providing answers privately. Thus, one factor that clearly affected conformity was the fear of social rejection.

In summary, the Asch Conformity Experiment results emphasize the strong influence of social pressure on individual behavior and the propensity to conform even in the face of clear evidence to the contrary, have become classic studies in social psychology.

Try it out in Labvanced:

A preview of the data and Asch Conformity Experiment results recorded in Labvanced can be seen in the image below, such as the values for the presented line heights, choices, and reaction times:

View of the data collected from an online version of the Asch Conformity Experiment conducted with Labvanced.

open in new window

# 2. Bobo Doll Experiment by Albert Bandura: Social Learning Theory

Frames from a video and images shown to the children who participated in the Bobo doll experiment. Copyright owner: Albert Bandura.

Social psychologist Albert Bandura carried out a groundbreaking study in 1961 called the Bobo Doll experiment, which made a substantial contribution to our understanding of children's social learning and aggression. Bandura was curious about how children learn to pick up new behaviors by imitation and observation.

In this experiment, children interacted with a life-sized inflatable doll called Bobo while being exposed to adult models who were aggressive and non-aggressive. The conditions of the study were as follows:

• Aggressive Model Condition: Children witnessed a role model act violently against the Bobo doll. Along with hitting and kicking, the aggressive actions included verbal abuse.
• Non-Aggressive Model Condition: Children witnessed a role model who did not act aggressively toward the Bobo doll.
• Control Group: No adult role model was seen interacting with the Bandura Bobo doll.

Children were placed in a room with the Bobo doll and other toys after looking at the conditions / models. The purpose of the study was to determine whether the children would imitate the violent acts they witnessed.

The Bobo Doll study produced some fascinating results. Compared to the control group and the non-aggressive model, children who watched the aggressive model were more likely to act aggressively toward the Bobo doll. This finding aligned with Albert Bandura's social learning theory which postulates that people learn new abilities through observing and imitating the behaviors of others. The girls in the aggressive model condition also reacted more physically aggressive when the model was male, but they responded more verbally when the model was female. The observation of how frequently they punched Bobo broke the general pattern of gender-inverted effects. It was also found that boys were more likely than girls to imitate same-sex models.

Our knowledge of the roles that imitation and observational learning play in children's development of aggressive behaviors has greatly increased as a result of Bandura’s Bobo doll study.

# 3. Stanford Prison Experiment by Philip Zimbardo

Experiment participants who had the role of a ‘guard’, pictured walking in the prison yard.

Social psychologist Philip Zimbardo carried out a study at Stanford University in 1971 that is known as the Stanford Prison Experiment. The experiment's goal was to find out how people would act in a prison simulation if they were in positions of power or powerlessness.

Out of the 75 volunteers, Zimbardo and his colleagues chose 24 male college students to take part in the study. The participants were divided into two groups at random and placed in a mock prison located in the Stanford psychology building's basement: guards or inmates.

The participants were completely absorbed in their parts; guards were deindividualized by being outfitted in sunglasses and uniforms, and inmates were given numbers rather than names. The guards started acting abusively and authoritarian toward the inmates as a result of the authority that had been bestowed upon them. In response, the inmates displayed symptoms of severe stress and emotional collapse.

The experiment was supposed to last two weeks, but because of the participants' severe psychological distress, it was called off after just six days! The experiment's inherent ethical issues surfaced as a result of the situation getting worse. The study has sparked ethical questions due to issues like incomplete debriefing, intense simulation, and incompletely informed consent. Because the participants' psychological well-being was compromised, Philip Zimbardo’s Stanford Prison Experiment has come under fire on a number of occasions.

In summary, the results for Philip Zimbardo’s Stanford experiment shed a light on how even ordinary beings can quickly adopt harmful and dangerous behaviors just because of their environment or roles. The Stanford Prison Experiment is frequently brought up in conversations concerning how circumstances can affect behavior and how people can misuse their power when they are in positions of authority.

# 4. Obedience Experiment by Stanley Milgram

The study setup of the Obedience experiment where the experimenter and student are confederates and the teacher who is the participant is instructed to administer shocks.

In the early 1960s, social psychologist Stanley Milgram carried out a number of contentious studies on submission to authority figures and the Milgram Experiment is the most well-known of these studies.

For the Obedience Experiment, three people were involved in the basic setup of the experiment: the learner (an associate of the experimenter), the teacher (a participant), and the experimenter (an authority figure). The ‘teacher’ participant was informed that the overall aim of the study was to examine the impact of punishment on learning and was directed to shock the student with progressively stronger electric shocks each time they erred on a memory task. The teacher participants were led to believe that the shocks were real (even though they weren't). Thus this setup was a mask for the real aim of the study: to assess to what extent an individual will be obedient to an authority figure, even in the case where their obedience is causing severe harm to others.

As the experiment went on, the experimenter (ie. the authority figure) would give the participant instructions to intensify the shocks while the learner, or confederate, made deliberate mistakes. Voltage levels ranging from mild to severe were labeled on the shocks, with the highest level indicating possible danger from 15 volts to 450 (danger – severe shock). Thus, the teacher could see how dangerous the high shock levels were and know they were ‘inflicting’ pain (even though the shocks were not real).

In summary, the key discovery of Milgram's Obedience to Authority experiment was that a sizable fraction of participants kept shocking the confederate even after they showed signs of distress, objected, and finally fell silent. The experiment result showed that a significant number of participants used the shock generator to its maximum capacity, demonstrating a high degree of submission to authority.

Because Stanley Milgram's Obedience study caused participants psychological distress, criticism and questions were raised pointing to its ethical issues. However, the study still managed to shed light on how common people might act dubiously or immorally when directed by an authority figure, offering insightful information about the influence of authority and social conformity.

# 5. The Hawthorne Effect by Henry A. Landsberger

A phenomenon known as the Hawthorne Effect occurs when people adjust their behavior when they become aware that they are being watched or observed by others. A set of experiments carried out at the Western Electric Hawthorne Works in Chicago in the 1920s and 1930s led to the naming of this effect. The initial purpose of the studies was to look into how worker productivity and lighting conditions relate to one another. Elton Mayo also studied in this context how work structure changes (like rest periods) influenced worked outcomes at the factory.

The data from the Hawthorne studies were later reanalyzed and interpreted in the 1950s by social scientist Henry A. Landsberger. His work, especially the 1958 paper "Hawthorne Revisited," was instrumental in making the Hawthorne Effect concept widely known.

Landsberger came to the conclusion that it was the workers' awareness of being observed/studied that actually explained the observed changes in worker productivity, rather than the lighting conditions as first believed. The workers' motivation and performance improved as a result of the researchers' interest and attention.

From then, the results from Hawthorne Effect study has gained widespread acceptance in organizational behavior psychology and social science. It emphasizes how crucial social and psychological elements are in shaping behavior, especially in settings like research or in the workplace where people may behave differently because they are aware that they are being watched or studied. The Hawthorne Effect is frequently brought up when talking about the difficulties in using human subjects in experiments and research because it can be difficult to identify and comprehend the underlying causes of observed behavior when subjects are aware they are being observed.

# Social Psychology Experiments Today

While these classic experiments helped establish the field of social psychology by studying complex topics like obedience and conformity, today there are more ethical guidelines that researchers must follow.

Furthermore, due to the digitization of the 21st century, online experiments are becoming more and more popular which allow for participants to complete tasks together using their computers or smartphones.

# References

• Asch, S. E. (1952). Group forces in the modification and distortion of judgments. In S. E. Asch, Social psychology (pp. 450–501). Prentice-Hall, Inc.
• Asch, S. E. (1953). Effects of group pressure upon the modification and distortion of judgements. Group dynamics. Asch, S. E. (1956). Studies of independence and conformity: I. A minority of one against a unanimous majority. Psychological monographs: General and applied, 70(9), 1.
• Bandura, A. (1965). Influence of models' reinforcement contingencies on the acquisition of imitative responses. Journal of personality and social psychology, 1(6), 589.
• Bandura, A., Ross, D., & Ross, S. A. (1961). Transmission of aggression through imitation of aggressive models. The Journal of Abnormal and Social Psychology, 63(3), 575.
• Bandura, A., Ross, D., & Ross, S. A. (1963). Imitation of film-mediated aggressive models. The Journal of Abnormal and Social Psychology, 66(1), 3.
• Bandura, A., & Walters, R. H. (1977). Social learning theory(Vol. 1). Prentice Hall: Englewood cliffs.
• Landsberger, H. A. (1958). Hawthorne Revisited: Management and the Worker, Its Critics, and Developments in Human Relations in Industry.
• Milgram, S. (1963). Behavioral study of obedience. The Journal of abnormal and social psychology, 67(4), 371.
• Milgram, S. (1965). Some conditions of obedience and disobedience to authority. Human relations, 18(1), 57-76.
• Zimbardo, P. G. (1973). On the ethics of intervention in human psychological research: With special reference to the Stanford prison experiment. Cognition, 2(2), 243–256.
• Zimbardo, P. G. (1995). The psychology of evil: A situationist perspective on recruiting good people to engage in anti-social acts. Japanese Journal of Social Psychology, 11(2), 125-133.

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Social Psychology Experiments

Social psychology experiments can explain how thoughts, feelings and behaviors are influenced by the presence of others.

This article is a part of the guide:

• Milgram Experiment
• Bobo Doll Experiment
• Stanford Prison Experiment
• Asch Experiment
• Milgram Experiment Ethics

Browse Full Outline

• 1 Social Psychology Experiments
• 2.1 Asch Figure
• 3 Bobo Doll Experiment
• 4 Good Samaritan Experiment
• 5 Stanford Prison Experiment
• 6.1 Milgram Experiment Ethics
• 7 Bystander Apathy
• 8 Sherif’s Robbers Cave
• 9 Social Judgment Experiment
• 10 Halo Effect
• 11 Thought-Rebound
• 12 Ross’ False Consensus Effect
• 13 Interpersonal Bargaining
• 14 Understanding and Belief
• 15 Hawthorne Effect
• 16 Self-Deception
• 17 Confirmation Bias
• 18 Overjustification Effect
• 19 Choice Blindness
• 20.1 Cognitive Dissonance
• 21.1 Social Group Prejudice
• 21.2 Intergroup Discrimination
• 21.3 Selective Group Perception

Typically social psychology studies investigate how someone's behavior influences a groups behavior or internal states, such as attitude or self-concept.

Obedience to Authority

"I was only following orders" Legal defence by a Nazi leader at the Nuremberg trial following World War II

The aftermath of World War 2 made scientists investigate what to made people "follow orders" even though the orders were horrible. The Stanley Milgram Experiment showed that also non-nazi populations would follow orders to harm other persons. It was not a German phenomenon as many thought.

Milgram's Lost Letter Experiment

Classic social psychology experiments are widely used to expose the key elements of aggressive behavior, prejudice and stereotyping. Social group prejudice is manifested in people's unfavorable attitudes towards a particular social group. Stanley Milgram's Lost Letter Experiment further explains this.

Obedience to a Role - Dehumanization

The Abu Ghraib prison-episode was yet another example on the power of predefined roles. The Stanford Prison Experiment by Philip Zimbardo, demonstrated the powerful effect our perception of expectations in roles have.

Solomon Asch wanted to test how much people are influenced by others opinions in the Asch Conformity Experiment .

Observational Role Learning

Behaviorists ruled psychology for a long time. They focused on how individuals learn by trying and failing. Albert Bandura thought that humans are much more than "learning machines". He thought that we learn from role models, initiating the (bandura) social cognitive theory. It all started with the Bobo Doll Experiment .

Helping Behavior - Good Samaritan

Knowing the story of the Good Samaritan makes you wonder what made the Samaritan help the stranger, and why did he not get help from the priest or the Levite? The Good Samaritan Experiment explores causes of not showing helping behavior or altruism.

Cognitive Dissonance Experiment

The Cognitive Dissonance Experiment by Leon Festinger assumes that people hold many different cognitions about their world and tests what happens when the cognitions do not fit. See also the more in depth article about the Cognitive Dissonance Experiment .

Bystander Effect

The Bystander Apathy Experiment was inspirated and motivation to conduct this experiment from the highly publicised murder of Kitty Genovese in the same year.

Groups and Influence On Opinion

Sherif's classic social psychology experiment named Robbers Cave Experiment dealt with in-group relations, out-group relations and intergroup relations.

The Social Judgment Experiment was designed to explore the internal processes of an individual's judgment and intergroup discrimination , how little it takes for people to form into groups, and the degree to which people within a group tend to favour the in-group and discriminate the out-group.

Halo Effect

The Halo Effect was demonstrated by Nisbett and Wilson's experiment. It fits the situation of Hollywood celebrities where people readily assume that since these people are physically attractive, it also follows that they are intelligent, friendly, and display good judgment as well. This also greatly applies to other well-known people such as politicians.

Wegner's Dream Rebound Experiment

According to studies, thoughts suppressed may resurface or manifest themselves in the future in the form of dreams. Psychologist Daniel M. Wegner proves this in his experiment on effects of thought suppression .

False Consensus

Everyone's got their own biases in each and every occasion, even when estimating other people behaviors and the respective causes. One of these is called the false consensus bias. Psychologist Professor Lee Ross conducted studies on setting out to show how false consensus effect operates.

Interpersonal Bargaining

Bargaining is one of the many activities we usually engage in without even realizing it. The Moran Deutsch and Robert Krauss Experiment investigated two central factors in bargaining, namely how we communicate with each other and the use of threats.

Understand and Belief

Daniel Gilbert together with his colleagues put to test both Rene Descartes' and Baruch Spinoza's beliefs on whether belief is automatic or is a separate process that follows understanding. This argument has long been standing for at least 400 years before it was finally settled.

Self-Deception

People lie all the time even to themselves and surprisingly, it does work! This is the finding of the Quattrone and Tversky Experiment that was published in the Journal of Personality and Psychology.

Overjustification Effect

The overjustification effect happens when an external incentive like a reward, decreases a person's intrinsic motivation to perform a particular task. Lepper, Greene and Nisbett confirmed this in their field experiment in a nursery school.

Chameleon Effect

Also called unintentional mirroring, the chameleon effect usually applies to people who are getting along so well, each tend to mimic each other's body posture, hand gestures, speaking accents, among others. This was confirmed by the Chartrand and Bargh experiments.

Confirmation Bias

Confirmation bias is also known as selective collection of evidence. It is considered as an effect of information processing where people behaves to as to make their expectations come true. People tend to favor information that confirms their preconceptions or hypotheses independently of the information's truthness or falsity.

Choice Blindness

Choice blindness refers to ways in which people are blind to their own choices and preferences. Lars Hall and Peter Johansson further explain this phenomenon in their study.

Stereotypes

The Clark Doll Test illustrates the ill effects of stereotyping and racial segregation in America. It illustrated the damage caused by systematic segregation and racism on children's self-perception at the young age of five.

Selective Group Perception

In selective group perception, people tend to actively filter information they think is irrelevant. This effect is demonstrated in Hastorf and Cantril's Case Study: They Saw a Game .

Changing Behaviour When Being Studied

The Hawthorne Effect is the process where human subjects of an experiment change their behavior, simply because they are being studied. This is one of the hardest inbuilt biases to eliminate or factor into the design.

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Oskar Blakstad (Oct 10, 2008). Social Psychology Experiments. Retrieved Dec 08, 2024 from Explorable.com: https://explorable.com/social-psychology-experiments

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