[Trending] 28 Psychological Experiments That Forever Changed The Way We See The World

Although as humans we have always been fascinated with the workings of the mind and the reasons behind our behavior, it wasn’t until the beginning of the 20^th century that Experimental psychology really took off.

Encompassing a range of areas, from behavioural studies to social dynamics and the complex biological processes occurring in the brain, the carefully controlled studies carried out in the name of experimental psychology have taught us so much about the human condition and given us a deeper understanding of why we act the way that we do.

Bored Panda has compiled a list of some of the most famous and thought-provoking psychology experiments that have been carried out in the last century. From simple social experiments to complex behavioural patterns that expose the workings of the subconscious and push the boundaries of ethics, these weird and wonderful experiments are sure to make you think twice about what you really know about yourself as a human being. Maybe we are all just a little less in control of ourselves than we really think… Check out the list below and don’t forget to vote for your favourite!

The Piano Stairs Experiment

A Volkswagen initiative called The Fun Theory set out to prove that people’s behavior can be changed for the better by making mundane activities fun. In this experiment, they set up musical piano steps on the staircase of a Stockholm, Sweden subway station to see if more people would be more willing to choose the healthier option and take the stairs instead of the escalator. The results revealed that 66 percent more people took the stairs than usual that day, proving that fun is the best way to get people to change their ways.

Image credits: thefuntheory

Robbers Cave Experiment

Image credits: Sherif

Smoke filled room experiment

In this experiment, researchers had participants sit in a room to fill out questionnaires. Suddenly, the room began to fill with smoke. In some cases the participants were alone, in others there were three unsuspecting participants with them. In the final iteration there was one participant and two actors who 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, a little under 40 percent reported the smoke. In the final condition where the two colleagues ignored the smoke, a mere 10 percent 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.

Image credits: Bibb Latane and John M. Darley

False Consensus Experiment

In this study, the researchers asked students on a college 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.

Image credits: Lee Ross

The Asch Conformity Experiment

The Asch Experiment is another famous example of the temptation to conform during group situations. This series of experiments conducted in the 1950s placed one subject in a room full of actors. The person conducting the experiment held up an image with three numbered lines and asked each person in the room to identify the longest line. The actors purposely chose the incorrect line in order to determine whether the subject would answer honestly or simply go along with the group answer. The results showed that people tend to conform in group situations.

Image credits: Solomon Asch

The Milgram Experiment

This experiment, conducted in 1961 by Yale University psychologist Stanley Milgram measured the willingness to obey authority figures by instructing people to perform acts that conflicted with their morals. Participants were told to play the role of teacher and administer electric shocks to the learner, who was supposedly in a different room, every time they answered a question incorrectly. In reality, no one was actually being shocked. Instead, Milgram played recordings to make it sound like the learner was in a great deal of pain and wanted to end the experiment. Despite these protests, many participants continued the experiment when the authority figure urged them to, increasing the voltage after each wrong answer until some eventually administered what would be lethal electric shocks.

Similar experiments conducted since the original have provided nearly identical results, indicating that people are willing to go against their consciences if they are being told to do so by authority figures.

Image credits: Stanley Milgram

The “Violinist in the Metro” Experiment

In 2007, acclaimed violinist Joshua 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 interested questions about how we not only value beauty but whether we truly stop to appreciate the remarkable works of beauty that are around us.

Image credits: Joshua Bell

The Marshmallow Test Experiment

In these experiments conducted by Walter Mischel in the late 1960s and early 1970s, children between the ages of four and six 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 higher educational levels. 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.

Image credits: IgniterMedia

Carlsberg Social Experiment

In this 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.

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.

Image credits: Carlsberg

Halo Effect Experiment

In this experiment, 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 honesty.

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 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.

Image credits: wiki

Stanford prison experiment

Zimbardo (1973) was interested in finding out whether the brutality reported among guards in American prisons was due to the sadistic personalities of the guards (i.e., dispositional) or had more to do with the prison environment (i.e., situational). Participants were randomly assigned to either the role of prisoner or guard in a simulated prison environment. Prisoners were treated like every other criminal. They were blindfolded and driven to the psychology department of Stanford University, where Zimbardo had had the basement set out as a prison, with barred doors and windows, bare walls and small cells. When the prisoners arrived at the prison they were stripped naked, deloused, had all their personal possessions removed and locked away, and were given prison clothes and bedding. They were issued a uniform, and referred to by their number only. The use of ID numbers was a way to make prisoners feel anonymous.

Within hours of beginning the experiment some guards began to harass prisoners. The prisoners soon adopted prisoner-like behavior too. The prisoners were taunted with insults and petty orders, they were given pointless and boring tasks to accomplish, and they were generally dehumanized. In less than a week the prisoners broke down emotionally and physically, while some guards became sadistic as they were escalating their abuse of prisoners in the middle of the night when they thought no researchers were watching and the experiment was “off.”

Zimbardo concluded that people will readily conform to the social roles they are expected to play, especially if the roles are as strongly stereotyped as those of the prison guards. The “prison” environment was an important factor in creating the guards’ brutal behavior (none of the participants who acted as guards showed sadistic tendencies before the study).

Image credits: Zimbardo

A Class Divided experiment

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 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.

Image credits: Jane Elliott

Bobo Doll Experiment

Albert Bandura conducted the Bobo Doll Experiment to prove that human behavior is largely based upon social imitation rather than inherited genetic factors.
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; and 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, while 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.

Image credits: Albert Bandura

Car Crash Experiment

Loftus and Palmer set out to prove just how deceiving memories can be. The 1974 Car Crash Experiment was designed to evaluate whether wording questions a certain way could influence a participant’s recall by twisting their memories of a specific event.
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.

Image credits: Loftus and Palmer

Cognitive Dissonance Experiment

The concept of cognitive dissonance refers to a situation involving conflicting attitudes, beliefs or behaviors. 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.

Festinger and Carlsmith conducted an experiment 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 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.

Image credits: Festinger, L., & Carlsmith, J. M.

Fantz’s Looking Chamber

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 to figure out this puzzle 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 and 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.

Image credits: Robert L. Fantz

Hawthorne Effect experiment

The Hawthorne Effect came from a 1955 study conducted by Henry Landsberger. This effect is a simple premise that human subjects in an experiment change their behavior simply because they are being studied.
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 within a building changed the productivity of the workers. What Mayo found was that the level of light made no difference in productivity, as 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, and 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.

Image credits: Henry A. Landsberger

Kitty Genovese Case

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 forty neighbors witnessed the event of Kitty Genovese being savagely attacked and murdered in Queens, New York in 1964, but 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.

Image credits: wiki

Learned Helplessness Experiment

In 1965, Martin Seligman and his colleagues were conducting research on classical conditioning, the process by which an animal or human associates one thing with another.
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 and 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, where a human or animal does not attempt to get out of a negative situation because the past has taught them that they are helpless.

Image credits: Martin Seligman

Little Albert experiment

The Little Albert experiment is considered to be among the most unethical psychological experiments of all time. The experiment was conducted in 1920 by John Watson and Rosalie Rayner at Johns Hopkins University. The hypothesis was that through a series of pairings, they could condition a nine-month-old child to develop an irrational fear.
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 the most important implications this finding has is that adult fears are often connected to early childhood experiences.

Image credits: John B. Watson and Rosalie Rayner

Pavlov’s Dog Experiment

Pavlov began with the simple idea that there are some things that a dog does not need to learn. Specific to his study he observed that dogs do not learn to salivate when they see food. This reflex is “hard wired” into the dog. In what became “behaviorist terms,” 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 (meaning it does not elicit any innate response). 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 and 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.

Image credits: Ivan Pavlov

The Invisible Gorilla Experiment

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.

Image credits: Daniel Simons and Christopher Chabris

Surrogate Mother Experiment

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. What the researcher found was 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 be more healthy.
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.

Image credits: Harry Harlow

The Good Samaritan Experiment

In 1973, an experiment was created by John Darley and Daniel Batson, to investigate the potential causes that underlie altruistic behavior. Student participants were given some religious teaching and instruction and 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, showing 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 a noticeable impact on the amount of helping behavior shown.

Image credits: John Darley and Daniel Batson

The “Monster” Study

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 twenty-two orphaned children, some with stutters and some without. The children were in two groups and 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, making them examples of the significance of positive reinforcement in education.
While the initial goal of the study was to investigate positive and negative speech therapy, the implication spanned much further into methods of teaching for young children.

Image credits: Wendell Johnson

The Third Wave experiment

When Ron Jones, a teacher at Palo Alto’s Cubberley High School, was struggling to answer “How was the Holocaust allowed to happen?” for his sophomore students in 1967, he resolved to show them instead. On the first day of his experiment, Jones created an authoritarian atmosphere in his class, positioning himself as a sort of supreme leader. But as the week progressed, Jones’ one-man brand of fascism turned into a school-wide club. Students came up with their own insignia and adopted a Nazi-style salute. They were taught to firmly obey Jones’ commands and become anti-democratic to the core, even “informing” on one another. Jones’ new ideology – dubbed “The Third Wave” – spread like wildfire. By the fourth day, the teacher was concerned that the Nazi-like movement he’d unleashed was getting out of hand, and he brought the experiment to a halt. On the fifth day, he told the students that they had invoked a similar feeling of supremacy to that of the German people under the Nazi regime.

Image credits: Ron Jones

Landis’ Facial Expressions Experiment

Psychology graduate student Carney Landis conducted an experiment at the University of Minnesota in 1924 to see whether all people have common facial expressions when feeling various emotions. The participants were made to smell ammonia, put their hands into a bucket of frogs, and watch pornography. The study took a turn for the worse when students were forced to decapitate a live rat. The study showed that humans do not have a common set of facial expressions tied to each emotion.

Image credits: Carney Landis

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