The Most Unbelievable Social Experiments Ever Conducted

Scientists have long felt the need to try and make sense of human behavior. This quest for knowledge about what makes humans tick led to a whole host of psychological experiments from the beginning of the 20th century onwards. The studies included in this list revealed surprising truths about us, but those findings — and the way they were arrived at — are not without some controversy. So without further ado, here are 13 of the most fascinating, controversial, and unbelievable psychological experiments in human history.

1. The Monopoly Experiment

A few years ago, psychologists led by a man named Paul Piff conducted the Monopoly Experiment at the University of California, Irvine. This experiment aimed to explore how accumulating wealth changes people.

As the name clearly suggests, the experiment required a Monopoly board, as well as pairs of strangers to play the game. But this was Monopoly with a difference: the game itself was totally rigged.

Disparity of rewards

Firstly, the strangers were made to flip a coin to decide who would be poor and who would be rich. Piff and his cohorts then provided the “rich” players with double the amount of money as their “poor” opponents at the start of the game.

Not only that, the “rich” players were allowed to throw the dice twice rather than once, enabling them to get around the board much faster than their “poor” opponents. They also received $200 when they passed “Go”, whilst their destitute opponents only collected $100.

Audible boasting about wealth

So, how did the “rich” players react to having more money and opportunities via the rigged game of monopoly? Dr. Piff told website Marketplace, “One possibility is that rich players are kind of embarrassed by the situation, doing what they can to help out this other person, who undeservedly is a poor player.”

Yet, as the academic noted from observing the game, the opposite was actually true. The undeserving rich were far from embarrassed, and actually lorded it over their “poor” opponents. This was illustrated through both their body language and audible boasting about their much-greater wealth.

Worrying findings

Yes, the “rich” players were observed mocking their “poor” opponents’ misfortune, at various points smacking their pieces down more aggressively against the board. Not only that, the “rich” players generally clearly acted as though they were deserving of their extra wealth, and essentially believed the good fortune was merited and because of their dice rolling. Tellingly, none of them attributed their success to luck in post-game interviews.

The Monopoly Experiment appeared to reveal a few startling things. Dr. Piff’s exploration of the empathy gap showed that having more money through good fortune didn’t tend to make that person more likely to share their wealth with others. Rather, the opposite was likely to be the case. As Dr. Piff told Marketplace, “When something good happens to you, we think about the things that we did that contributed to that success. That can be a problem when it comes to inequality, which has skyrocketed in advanced economies in recent decades.”

2. The Stanford Prison Experiment

The Stanford Prison Experiment is one of the most infamous psychological experiments ever conducted. As its name suggests, was conducted by Stanford University in California, and the year that it took place was 1971. The aim of the experiment was to examine the psychological effects of perceived power, with a specific focus on the struggle between prison officers and the prisoners under their watch.

Would the people given a significant degree of control over others eventually start to abuse that power? And would those put in a powerless situation become submissive? Philip Zimbardo led the research group that conducted the experiment; the psychology professor used college students as his subjects.

Treated like real prisoners

The volunteers who agreed to partake in the experiment were randomly split into two groups: one was given the role of the guards and the other comprised the inmates at a mock prison constructed at Stanford. Dr. Zimbardo’s experiment sought to test the theory that the principal cause of abusive behavior in a prison setting was the inherent personality traits of prisoners and guards.

Dr. Zimbardo needed it to be as realistic as possible, so the students who made up the prisoners were treated like genuine criminals. For instance, upon arrival at the mock penitentiary, they had all their personal possessions taken from them. They were stripped and deloused, and they had to don prison clothes and sleep in a prison bed. What’s more, the prisoners were only referred to by an ID number, to make them feel effectively anonymous.

Abuse of "prisoners"

It only took a few hours of the experiment elapsing to see the new power dynamic take effect. The students who had been made into guards began to harass the “prisoner” students with verbal insults, and started assigning them with mundane or pointless tasks. Close to a week in, several of the guards had become even crueler, abusing the prisoners to a greater and greater degree.

Meanwhile, several of the students who’d comprised the prisoners had emotional or physical breakdowns. The cruelty exhibited was so extreme that the study was abandoned before its scheduled end date.

Social roles

The conclusion of Dr. Zimbardo’s study — which was later criticized for its unscientific methodology, such as telling participants how to behave — was that humans tended to conform to the social roles that they were given, particularly if those were widely stereotyped ones.

Ultimately, then, the main driver of behavior was the social role or situation that groups found themselves in, rather than their individual personalities. For instance, none of the students who’d comprised the guards had exhibited any psychopathic or sadistic personality traits before they’d joined the experiment, nor had the “prisoners” shown any signs of being submissive.

3. The Brain-hacking Experiment

A few years back, academics from the University of California at Berkeley linked up with the University of Oxford, U.K., and the University of Geneva, Switzerland, for a unique study. The resulting academic paper — which was published in 2012 — was titled On the Feasibility of Side-Channel Attacks with Brain-Computer Interfaces.

Now, to the layman, that title might sound like complete gobbledygook. Don’t worry if you can’t make head nor tail of it: we were just as perplexed as you! So, to simplify things, we are going to call it what it essentially was: a brain-hacking experiment.

Brain-Computer Interfaces

What, then, was its main purpose? The short answer to that is to analyze the possible nefarious uses of Brain-Computer Interfaces (BCIs). But of course, there were other aspects to it too, and the study ultimately highlighted the potential of the technology used in it for communicating with people who cannot engage in speech or sign language, such as the severely paralyzed.

In the experiment, volunteers had to don an electroencephalogram headset or cap, often called an EEG. These 30 individuals — who were all in good health — then had to watch a screen which the aforementioned academics had programmed to display images of ATM machines, debit cards, maps, people, and finally the numbers 0 to 9 in a mixed-up order.

Upticks in neural activity

Whilst their participants were wearing the headsets and gazing at these separate images, the academic researchers examined the EEG data for any peaks they could detect in their neural activity.

If there was an uptick in such activity — which is sometimes called a P300 response — then that would suggest the person was most likely to be familiar with an image shown, or had a connection to a particular number. But what is the significance of that, you ask?

Potential to steal PINs and passwords

Well, the study showed that from those peaks in neural activity, it was possible to deduct some important things. Yes, with the help of some software, the researchers could extract personal information from the participants, including their date of birth and their debit or credit card’s ATM PIN code.

Just by reviewing the neural spikes, the academics were able to guess these personal secrets with worrying accuracy: they gots dates of birth right about 60 percent of the time and guessed PINs accurately at a rate of between 20 and 30 percent. This means that someone could potentially use this technology to steal your PIN, and perhaps your passcodes and passwords too. Let’s hope criminals don’t find ways of exploiting this technology any time soon!

4. The Robbers Cave Experiment

The infamous Robbers Cave Experiment took place in 1954. It was overseen by Muzafer Sherif and his wife Carolyn Wood Sherif; it remains one of the best-known experiments in what is called Realistic Conflict Theory (RCT).

To conduct the experiment, the doctors had to recruit 22 boys aged between 11 and 12, all of whom had never previously met. All the same, the boys selected were all from similar backgrounds and of the same ethnicity: white, Protestant, middle-class, and from a two-parent home.

Boys split into two groups

After those 11- and 12-year-old boys had been selected, they were brought to the place that gives the experiment its name: Robbers Cave State Park in Oklahoma. Once at that 200-acre “summer camp” the two groups of boys were split into two, the academics making sure that they never met or were even aware of those designated to the other group.

The boys in each faction were given a range of activities to do with one another, including swimming and hiking. They proceeded to bond with the others in their group during those first few days.

Separate bonding then manipulated competition

After those first few days of the separate groups of boys bonding, the Dr.s Sherif brought them all back together. Almost straightaway, there was evidence of mutual dislike, which was enhanced considerably when the groups were deliberately pitted against one another by the conductors of the experiment.

The researchers organized four days of games between the two groups, in which they deliberately manipulated the results to make the scores appear extremely close. This led to the development of a readily noticeable prejudice between the two groups.

No consent or awareness

The academics then allowed the boys to have a two-day period away from the other group, and during that time the boys tended to portray their own group very favorably and the other one in unfavorable terms. Lastly, in the third week, the groups were brought together to solve common problems, such as a drinking-water issue. After they had worked together on various things, the groups began to bond across their lines.

The Robbers Cave Experiment illustrated how negative attitudes and behaviors can arise between groups when there is a fierce competition over limited resources. It also demonstrated that inter-group socialization and working together to solve common problems can greatly reduce prejudice and discrimination. Yet the experiment was very controversial because it used unwitting children as its test subjects without consent or awareness of what was going on.

5. The Violinist In The Metro Experiment

The Violinist In The Metro Experiment took place on the morning of January 12, 2007. With no prior warning or advertising, one of the world’s best-regarded violin players performed a free-mini concert as around 1,000 people traipsed through a Washington, DC, metro station.

That violinist was Joshua Bell, a Grammy Award-winning virtuoso who has enjoyed a nearly four-decade career in music. The American has performed with nearly all of the world’s major orchestras, and continues to play today.

High-level 45-minute set

On that January morning, Bell proceeded to play an extremely technical and high-level 45 minute set. On his handcrafted 1713 Stradivarius violin worth millions, he performed six complicated classical pieces, two of which were composed by German great Johann Sebastian Bach.

The set by Bell was of course being observed by researchers. The Washington Post writer Gene Weingarten had set it all up “as an experiment in context, perception, and priorities — as well as an unblinking assessment of public taste: in a banal setting at an inconvenient time, would beauty transcend?”

Little fanfare

The experiment yielded some interesting results. During the 45-minute virtuoso performance, only six subway users stopped for a significant period to take it in and enjoy it; in some cases, parents grabbed their children who had stopped to listen. Approximately 20 people dropped some money in his case; the sum amounted to a measly $32.

After Bell had finished, there was no applause or fanfare: one the world’s premier classical musicians had barely been noticed by passersby. Weingarten’s experiment raised numerous thought-provoking questions about how much we truly value beauty and talent, and how advertising, promotion, setting and presentation alter our perceptions. Just three days earlier Bell had played to a full house at Boston’s Symphony Hall. Maybe the experiment lays bare a degree of musical snobbery?

6. The Facebook Experiment

In 2012 an experiment took place on social media site Facebook; it has since become widely known as simply “The Facebook Experiment.” The study would cause a great deal of controversy, but we will get to that shortly.

As revealed in a scientific paper published in the Proceedings of the National Academy of Sciences, The Facebook Experiment involved tampering with the news feeds of approximately 70,000 unwitting users.

Manipulation of posts

Those Facebook users were shown an atypically low amount of either positive or negative posts. This data was collated, and their responses to this manipulation were monitored, if there were any. So, we are talking about positive or negative updates and comments on their page, or elsewhere on the site.

The Facebook Experiment was essentially a psychological test to measure the effects of positive and negative posts on users, and their subsequent behavior on the social network. Could the site alter the emotional state of its users simply by determining what kind of posts they saw?

Results and manipulation controversy

The data collected showed unequivocally that the site’s users were susceptible to “emotional contagion.” That means that they tended to mimic the type of content of others whose content was posted on their feed. An example would be that users who were shown more negative comments tended to post more negative comments themselves.

 When word got out about The Facebook Experiment via the published paper, many people felt a sense of outrage that they might have been secretly manipulated by the social-media company. There were also Orwellian Big-Brother style concerns over users being watched and controlled, with critics slamming Facebook’s actions as “terrifying” and “creepy.”

7. Surrogate Mother Experiment

The Surrogate Mother Experiment was the brainchild of Harry Harlow. Across the late 1950s and early 1960s he decided to conduct an academic study on the perceived importance of a mother’s love on a child’s development. Instead of getting humans involved though, Dr. Harlow instead conducted a number of experiments on one of our closest evolutionary relatives: monkeys.

So, after getting hold of several female rhesus monkeys and their infant children, he got to work on observing how they would react to situations of isolation and separation. To begin with, he separated biological mothers from their infant monkeys just 6-12 hours after birth. Those newborn infants were then put in a nursery with two fake “surrogate” mothers of the same size, one made from wire mesh and the other constructed out of wood and covered in a soft and cuddly cloth.

Choice vs. no choice

The first phase of the experiment that Dr. Harlow conducted saw both “surrogates” placed in the enclosure with some the infant monkeys. This effectively gave them a choice of which one to go to, the wire-mesh mom or the wood-and-cloth one. Both of those fake moms were set up to supply nourishment in the form of milk to the baby monkeys.

The second experiment saw the element of choice eliminated for the monkeys. This time around, they were split into two separate groups, one of which went in with a wire-mesh mom and the other with the soft-cloth “surrogate.” An occasional threat was posed to them too, to see if they went to their “mother” for comfort.

Different reactions to perceived threats

Dr. Harlow observed the baby monkeys for a significant period, and he came to some clear conclusions. Firstly, though the wire-mesh mom also provided nourishment, the monkeys preferred to spend their time with the soft-cloth one: they cuddled and were affectionate with that “surrogate,” seemingly proving that their interactions were not merely for nourishment.

The second experiment, meanwhile, showed that the infant monkeys from both groups consumed the same amount of milk from their designated “surrogate” mother. Yet the infants who grew up with the soft-cloth mother showed a level of emotional attachment and expected behavior to that “surrogate” mom when threatened, going to cuddle it and seek protection. The monkeys in with the wire-cloth surrogate did not do this: they instead threw themselves to the ground in a defensive manner.

8. The Divided Class Experiment

The assassination of civil rights leader Martin Luther King Jr. in 1968 had a profound effect on a lot of people. Among those deeply saddened by the death of Dr. King was teacher Jane Elliott.

Elliott of Riceville, Iowa, had a third-grade class at the time; she tried to breach important social issues such as racism, discrimination, and prejudice with them. But Elliott found that she was struggling to make any impression on them.

Lesson about discrimination

Elliott discovered that the students in her class did not have any regular interaction with the minorities that resided in Riceville. So, she decided to conduct an experiment on them, one that we have dubbed The Divided Class Experiment.

Elliott aimed to teach her class the innate injustice and inequality that racism and discrimination bring to the table. So she spearheaded a two-day experiment for her blue-eyed and brown-eyed children.

Thought-provoking results

So, for one of the two days, Elliott consciously gave students with blue eyes preferential treatment. She provided them with ample positive reinforcement, and endeavored to make them feel superior over those with brown eyes. The next day, she completely reversed the experiment.

What did Mrs. Elliott discover? Well, the Iowa-based teacher found out that whichever group was favored by her on their given day were more active in class, answering questions accurately and speedily. Not only that, they actually did better in tests too. On the flip side, those discriminated against on one of the days performed worse in tests, were less actively engaged in lessons and were uncertain in their answers.

9. The Invisible Gorilla Experiment

Researchers Dan Simons and Christopher Chabris organized what has now become widely known as The Invisible Gorilla Experiment back in 1999. Their study took place on a basketball court at Harvard University.

To begin with, Simons and Chabris recruited six willing volunteers. They were required to make some passes with players wearing the same color shirt as them on the basketball court. Three of the six volunteers were made to wear white shirts, and the other three black.

Gorilla arrives on court

Beforehand, the players had been tasked with silently keeping track of how many times the opposition basketball players tossed the basketball between themselves. As they concentrated on the game and this task, a person dressed in a black gorilla suit suddenly wandered onto the basketball court.

The gorilla-suited person walked not around the periphery of the court, but right into the middle of the action for up to nine seconds: it even beat its chest. But many of the black- and white-shirted volunteers failed even to notice its presence!

Sustained inattentional blindness

How could this be possible, you ask? Well, the experiment brought to light something that has been called “sustained inattentional blindness.” At least half of the people who were made to watch the video of the experiment and count passes missed the gorilla, too!

The Invisible Gorilla Experiment essentially revealed that when humans are focusing very closely on one thing, we can often miss other events that are occurring in our field of vision: even large gorillas beating their chests! Perhaps this experiment revealed a flaw in our evolution: what if that gorilla had been intending to attack us?

10. The Bobo Doll Experiment

Back in 1961 The Bobo Doll Experiment was carried out by Albert Bandura, a Canadian–American psychologist who held the post of Professor of Social Science in Psychology at Stanford University.

Dr. Bandura ran The Bobo Doll Experiment to test his hypothesis that all human behavior was in fact learned from others, largely via social imitation and copying. This belief opposed the school of thought that put it down to inheritance and genetic factors.

Three different groups

In order to prove his hypothesis that children essentially copied adult role models’ behavior’, Dr. Bandura separated his young participants into three distinct groups. One of these groups was exposed to an adult who displayed aggression towards a Bobo doll. The second saw a passive adult playing normally with that particular doll, while the third was a control group that had no exposure to any adults.

The young participants were then directed to a room on their own, in which there were various toys, including the Bobo doll. Yet Dr. Bandura instructed them not to play with the toys, saying that they had been reserved for other kids. The psychologist did this to ramp up the frustration in his young subjects.

Dr. Bandura’s findings

So, what were the results? Well, the experiment discovered that children who had been exposed to the aggressive adult were more likely to display aggressive behavior towards the Bobo doll themselves. Conversely, the other two groups who had been exposed to a placid adult or had seen no adult at all exhibited little signs of aggression or what most would deem bad behavior.

And there was a difference highlighted between the sexes with regard to the aggressive-adult group: boys showed a much higher tendency to copy the adult’s physically aggressive behavior. The experiment clearly showed that children learn not only by being rewarded or punished themselves, but by observing others being rewarded or punished.

11. The Monster Study Experiment

The Monster Study Experiment was carried out in 1939. Its leader was Wendell Johnson, an American psychologist and speech pathologist. Dr. Johnson was trying to figure out why people stutter, so he came up with an experiment to try and identify a root cause.

Dr. Johnson was sure in his mind that the widely held belief about stuttering being an inborn trait that could not be corrected was wrong. So the American psychologist enlisted a group of children who were in an orphanage in Davenport, Iowa, to try to prove he was right.

Stuttering and non-stuttering groups

For the experiment, Dr. Johnson enlisted 22 orphans from the Davenport orphanage, and divided them into two groups, ostensibly composed of stutterers and non-stutterers. In fact, only half of the orphaned children placed in the stuttering group were actually sufferers.

As Dr. Johnson conducted his experiment, the non-stutterers were given substantial praise for their ability to speak conventionally. Conversely, those orphans who were in the stuttering group received constant negative reinforcement, their anxiety greatly increased by reminders not to stutter.

Developmental, not innate

What were the results? Well, Dr. Johnson discovered that the orphaned children in the stuttering group who had originally been sufferers actually found it even harder not to stutter. And the kids in the stuttering group who hadn’t been afflicted prior to the experiment actually began stuttering themselves by the end of it.

Dr. Johnson deduced from his experiment that stuttering was a developmental problem, rather than an innate trait. But the academic not unnaturally received heavy criticism for the way he’d conducted his research: it had effectively left many of the children with a lifelong speech problem.

12. The Smoke-filled Room Experiment

The Smoke Filled Room Experiment — a.k.a. the Smoke Room Study — was carried out in 1968 at the behest of Bibb Latané and John M. Darley. The American social psychologists wanted to create an apparently dangerous scenario to test whether people would report the situation or not when others who were witnessing it too remained passive.

Dr. Darley and Dr. Latané spearheaded the study in response to the real-life case of Kitty Genovese. This Italian-American woman had been murdered in New York in March 1964 despite there being 38 people who had either witnessed or heard her trying to fight off her attacker.

Naïve participants

How was the experiment carried out? Well, the academics had a few different setups. They essentially recruited three sets of naïve participants — who didn’t know what was going to happen — and a few actors who did. So, the naïve participants were put in a room and told to start filling out a questionnaire.

Soon after they were in there, smoke would begin to seep in and fill the room from under the door. The first set of participants were each left in the room solo; the second set comprised one naïve participant and two actors who had been told to completely ignore the smoke. Finally, the third set featured three naïve participants together.

Group behavior influence

The researchers watched and recorded through a one-way mirror exactly how long it took for each participant to leave the room in order to report the danger of the smoke. The experiment’s results showed that the naïve participants who had been left to their own devices had quit the room 75 percent of the time in order to report the smoke.

Yet the participants placed with the two unconcerned actors had only left to report it 10 percent of the time, whilst the room with three participants together had recorded 38 percent by the same metric. What does this all mean? Well, the study clearly suggested that when humans are faced with an ambiguous or dangerous situation, then group behavior can influence a single bystander. This can lead to a misinterpretation of dangerous situations since dubbed “pluralistic ignorance.” In other words, sometimes we mistakenly rely on others’ actions rather than our own instincts.

13. The Milgram Experiment

Stanley Milgram oversaw one of the most infamous academic reports on obedience back in 1963. The Yale University psychologist led The Milgram Experiment; it was one which produced some literally shocking findings.

Dr. Milgram had become interested in the topic of obedience in 1963 after reading the justifications made by people — predominantly Nazis — accused of committing acts of genocide during World War II. Typically, they’d sought to defend or lower their culpability based on the notion of “obedience,” essentially arguing that they were just following the orders of their superiors. Dr. Milgram wondered whether Germans were somehow innately obedient, or whether there had been other psychological reasons behind the Nazis’ hideous cruelty.

Recruiting participants and confederates

Dr. Milgram decided to conduct a psychological experiment to analyze obedience to authority and personal conscience, and the conflict between the two. He put out an ad in a newspaper asking for people to take part in a study at Yale University.

Once he’d got enough people, the academic paired each recruit with another participant, who was actually an actor or confederate there to help Dr. Milgram with his experiment. The genuinely recruited participants were designated as “teachers” whilst the confederates played the role of the “learners.”

Conducting the electricity and experiment

Dr. Milgram then directed “learners” into one room, and “teachers” into another. Within each “teacher’s” room was an electric shock device, plus a row of switches ranging from a low of 15 volts to a high of 450 volts.

The academic then instructed the “teacher” to press the “shock” switches numerous times, at increasingly high voltages. The “teachers,” though, were unaware that they were not real, and that the “learners” had been faking electric shock reactions.

Results and conclusions

In fact, had the electric shocks at the higher end of the scale been genuine, they would have easily killed the “learners.” But that didn’t stop the “teachers” from pressing the switches that would have delivered fatal shocks, had they been real.

The results of the experiment were arguably not great as far as humanity and future ethnocentric or religious conflicts were concerned. The Milgram Experiment had unexpectedly shown that a high proportion of participants would fully obey the instructions to administer fatal electric shocks, even if they did so with reservations.