8 Famous Social Experiments

A social experiment is a type of research performed in psychology to investigate how people respond in certain social situations. 

In many of these experiments, the experimenters will include confederates who are people who act like regular participants but who are actually acting the part. Such experiments are often used to gain insight into social psychology phenomena.

Do people really stop to appreciate the beauty of the world? How can society encourage people to engage in healthy behaviors? Is there anything that can be done to bring peace to rival groups?

Social psychologists have been tackling questions like these for decades, and some of the results of their experiments just might surprise you.


Robbers Cave Social Experiment

children playing in a forest
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Why do conflicts tend to occur between different groups? According to psychologist Muzafer Sherif, intergroup conflicts tend to arise from competition for resources, stereotypes, and prejudices. In a controversial experiment, the researchers placed 22 boys between the ages of 11 and 12 in two groups at a camp in the Robbers Cave Park in Oklahoma.

The boys were separated into two groups and spent the first week of the experiment bonding with their other group members. It wasn't until the second phase of the experiment that the children learned that there was another group, at which point the experimenters placed the two groups in direct competition with each other.

This led to considerable discord, as the boys clearly favored their own group members while they disparaged the members of the other group. In the final phase, the researchers staged tasks that required the two groups to work together. These shared tasks helped the boys get to know members of the other group and eventually led to a truce between the rivals.


The 'Violinist in the Metro' Social Experiment

man playing violin
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In 2007, acclaimed violinist Josh Bell posed as a street musician at a busy Washington, D.C. subway station. Bell had just sold out a concert with an average ticket price of $100 each.

He is one of the most renowned musicians in the world and was playing on a handcrafted violin worth more than $3.5 million. Yet most people scurried on their way without stopping to listen to the music. When children would occasionally stop to listen, their parents would grab them and quickly usher them on their way.

The experiment raised some interesting questions about how we not only value beauty but whether we truly stop to appreciate the remarkable works of beauty that are around us.


The Piano Stairs Social Experiment

stairs and escalators
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How can you get people to change their daily behavior and make healthier choices? In one social experiment sponsored by Volkswagen as part of their Fun Theory initiative, making even the most mundane activities fun can inspire people to change their behavior.

In the experiment, a set of stairs was transformed into a giant working keyboard. Right next to the stairs was an escalator, so people were able to choose between taking the stairs or taking the escalator. The results revealed that 66% more people took the stairs instead of the escalator.

Adding an element of fun can inspire people to change their behavior and choose the healthier alternative.


The Marshmallow Test Social Experiment

child with marshmallows
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During the late 1960s and early 1970s, a psychologist named Walter Mischel led a series of experiments on delayed gratification. Mischel was interested in learning whether the ability to delay gratification might be a predictor of future life success.

In the experiments, children between the ages of 3 and 5 were placed in a room with a treat (often a marshmallow or cookie). Before leaving the room, the experimenter told each child that they would receive a second treat if the first treat was still on the table after 15 minutes.

Follow-up studies conducted years later found that the children who were able to delay gratification did better in a variety of areas, including academically. Those who had been able to wait the 15 minutes for the second treat tended to have higher SAT scores and more academic success (according to parent surveys).

The results suggest that this ability to wait for gratification is not only an essential skill for success but also something that forms early on and lasts throughout life.


The Smoky Room Social Experiment

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If you saw someone in trouble, do you think you would try to help? Psychologists have found that the answer to this question is highly dependent on the number of other people present. We are much more likely to help when we are the only witness but much less likely to lend a hand when we are part of a crowd.

The phenomenon came to the public's attention after the gruesome murder of a young woman named Kitty Genovese. According to the classic tale, while multiple people may have witnessed her attack, no one called for help until it was much too late.

This behavior was identified as an example of the bystander effect, or the failure of people to take action when there are other people present. (In reality, several witnesses did immediately call 911, so the real Genovese case was not a perfect example of the bystander effect.) 

In one classic experiment, researchers had participants sit in a room to fill out questionnaires. Suddenly, the room began to fill with smoke. In some cases the participant was alone, in some there were three unsuspecting participants in the room, and in the final condition, there was one participant and two confederates.

In the situation involving the two confederates who were in on the experiment, these actors ignored the smoke and went on filling out their questionnaires. When the participants were alone, about three-quarters of the participants left the room calmly to report the smoke to the researchers.

In the condition with three real participants, only 38% reported the smoke. In the final condition where the two confederates ignored the smoke, a mere 10% of participants left to report the smoke. The experiment is a great example of how much people rely on the responses of others to guide their actions.

When something is happening, but no one seems to be responding, people tend to take their cues from the group and assume that a response is not required.


Carlsberg Social Experiment

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Have you ever felt like people have judged you unfairly based on your appearance? Or have you ever gotten the wrong first impression of someone based on how they looked? Unfortunately, people are all too quick to base their decisions on snap judgments made when they first meet people.

These impressions based on what's on the outside sometimes cause people to overlook the characteristics and qualities that lie on the inside. In one rather amusing social experiment, which actually started out as an advertisement, unsuspecting couples walked into a crowded movie theater.

All but two of the 150 seats were already full. The twist is that the 148 already-filled seats were taken by a bunch of rather rugged and scary-looking male bikers. What would you do in this situation? Would you take one of the available seats and enjoy the movie, or would you feel intimidated and leave?

In the informal experiment, not all of the couples ended up taking a seat, but those who eventually did were rewarded with cheers from the crowd and a round of free Carlsberg beers.

The exercise served as a great example of why people shouldn't always judge a book by its cover.


Halo Effect Social Experiment

woman with halo
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In an experiment described in a paper published in 1920, psychologist Edward Thorndike asked commanding officers in the military to give ratings of various characteristics of their subordinates.

Thorndike was interested in learning how impressions of one quality, such as intelligence, bled over onto perceptions of other personal characteristics, such as leadership, loyalty, and professional skill. Thorndike discovered that when people hold a good impression of one characteristic, those good feelings tend to affect perceptions of other qualities.

For example, thinking someone is attractive can create a halo effect that leads people also to believe that a person is kind, smart, and funny. The opposite effect is also true. Negative feelings about one characteristic lead to negative impressions of an individual's other features.

When people have a good impression of one characteristic, those good feelings tend to affect perceptions of other qualities.


False Consensus Social Experiment

man with sign
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During the late 1970s, researcher Lee Ross and his colleagues performed some eye-opening experiments. In one experiment, the researchers had participants choose a way to respond to an imagined conflict and then estimate how many people would also select the same resolution.

They found that no matter which option the respondents chose, they tended to believe that the vast majority of other people would also choose the same option. In another study, the experimenters asked students on campus to walk around carrying a large advertisement that read "Eat at Joe's."

The researchers then asked the students to estimate how many other people would agree to wear the advertisement. They found that those who agreed to carry the sign believed that the majority of people would also agree to carry the sign. Those who refused felt that the majority of people would refuse as well.

The results of these experiments demonstrate what is known in psychology as the false consensus effect.

No matter what our beliefs, options, or behaviors, we tend to believe that the majority of other people also agree with us and act the same way we do.

A Word From Verywell

Social psychology is a rich and varied field that offers fascinating insights into how people behave in groups and how behavior is influenced by social pressures. Exploring some of these classic social psychology experiments can provide a glimpse at some of the fascinating research that has emerged from this field of study.

Frequently Asked Questions

  • What is an example of a social experiment?

    An example of a social experiment might be one that investigates the halo effect, a phenomenon in which people make global evaluations of other people based on single traits. An experimenter might have participants interact with people who are either average looking or very beautiful, and then ask the respondents to rate the individual on unrelated qualities such as intelligence, skill, and kindness. The purpose of this social experiment would be to seek if more attractive people are also seen as being smarter, more capable, and nicer.

  • What was one of the best known social experiments?

    The Milgram obedience experiment is one of the most famous social experiments ever performed. In the experiment, researchers instructed participants to deliver what they believed was a painful or even dangerous electrical shock to another person. In reality, the person pretending to be shocked was an actor and the electrical shocks were simply pretend. Milgram's results suggested that as many as 65% of participants would deliver a dangerous electrical shock because they were ordered to do so by an authority figure.

  • What defines a social experiment?

    A social experiment is defined by its purpose and methods. Such experiments are designed to study human behavior in a social context. They often involved placing participants in a controlled situation in order to observe how they respond to certain situation or events. 

  • What are some social psychology experiment ideas?

    A few ideas for simple social experiments might involve:

    • Stand in a crowd and stare at a random spot on the ground to see if other people will stop to also look
    • Copy someone's body language and see how they respond
    • Stand next to someone in an elevator even if there is plenty of space to stand elsewhere
    • Smile at people in public and see how many smile back
    • Give random strangers a small prize and see how they respond
9 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Sherif M. Superordinate goals in the reduction of intergroup conflict. American Journal of Sociology. 1958;63(4):349-356. doi:10.1086/222258

  2. Peeters M, Megens C, van den Hoven E, Hummels C, Brombacher A. Social Stairs: Taking the Piano Staircase towards long-term behavioral change. In: Berkovsky S, Freyne J, eds. Lecture Notes in Computer Science. Vol 7822. Springer, Berlin, Heidelberg; 2013. doi:10.1007/978-3-642-37157-8_21

  3. Mischel W, Ebbeson EB, Zeiss A. Cognitive and attentional mechanisms in delay of gratification. Journal of Personality and Social Psychology. 1972;21(2):204–218. doi:10.1037/h0032198

  4. Mischel W, Shoda Y, Peake PK. Predicting adolescent cognitive and self-regulatory competencies from preschool delay of gratification: Identifying diagnostic conditions. Developmental Psychology. 1990;26(6):978-986. doi:10.1037/0012-1649.26.6.978

  5. Benderly, BL. Psychology's tall tales. gradPSYCH Magazine. 2012;9:20.

  6. Latane B, Darley JM. Group inhibition of bystander intervention in emergencies. Journal of Personality and Social Psychology. 1968;10(3):215-221. doi:10.1037/h0026570

  7. Thorndike EL. A constant error in psychological ratings. Journal of Applied Psychology. 1920;4(1):25-29. doi:10.1037/h0071663

  8. Talamas SN, Mayor KI, Perrett DI. Blinded by beauty: Attractiveness bias and accurate perceptions of academic performance. PLoS One. 2016;11(2):e0148284. doi:10.1371/journal.pone.0148284

  9. Ross, L, Greene, D, & House, P. The "false consensus effect": An egocentric bias in social perception and attribution processes. Journal of Experimental Social Psychology. 1977;13(3):279-301. doi:10.1016/0022-1031(77)90049-X

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