25 Mind Blowing Psychology Experiments

Posted by , Updated on April 23, 2024

Have you ever wondered why people act the way they do? It’s likely that you’ve pondered this question before. The field of psychology has been delving into this issue for decades, resulting in many revelations about the human mind from research over the last century. While some of these studies have raised ethical questions, they’ve all had a significant impact on improving human life. Ranging from Asch’s Conformity Experiment to Zimbardo’s Stanford Prison Experiment, the psychologists mentioned in this list have made considerable contributions to our growing knowledge and comprehension of human behavior and cognition that often seems unpredictable. Here are 25 Remarkable Psychology Experiments!


Selective Attention Test


Do you think you’re pretty observant? There’s one way to find out. Click on the video link above. Did you get the correct answer? If you did, congratulations! But the more important question is: Did you notice the man in the gorilla suit? In Simons and Chabris’ famous awareness test, subjects were asked to count how many passes occurred between basketball players on the white team. 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 didn’t notice the gorilla at all, proving that humans often overestimate their ability to effectively multi-task.


Violinist in the Metro Station

street performer

Do you take the time to stop and appreciate the beauty around you? According to an experiment conducted in 2007, chances are you don’t. World famous violinist Josh Bell posed as a street musician in a Washington D.C. metro station to see how many people would stop and listen. Despite the fact that he was playing a $3.5 million handcrafted violin and had just sold out a concert in Boston where ticket prices averaged $100 each, very few people stopped to appreciate his beautiful performance. He made a measly $32 that day.


Piano Stairs

piano stairs

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 a recent 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. That day, 66 percent more people took the stairs than usual, proving that fun is the best way to get people to change their ways.


The Milgram Experiment

milgram experiment

Humans are trained to take direction from authority figures from very early in life. An experiment conducted in 1961 by Yale University psychologist Stanley Milgram measured this 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.


The Marshmallow Test


Can deferred gratification be an indicator of future success? This is what Walter Mischel of Stanford University sought to determine in his 1972 Marshmallow Experiment. Children ages four to six were taken into a room where a marshmallow was placed on the table in front of them. Before leaving each of the children alone in the room, the examiner told them they would receive a second marshmallow if the first was still on the table after 15 minutes. The examiner recorded how long each child resisted eating the marshmallow and later noted whether it correlated with the child’s success in adulthood. A minority of the 600 children ate the marshmallow immediately and one-third deferred 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, meaning that this characteristic likely remains with a person for life.


The Bystander Effect


In case of an emergency, most people would probably want to be in a busy area so they have a higher chance of receiving help. Contrary to popular belief, being surrounded by people doesn’t guarantee anything. A psychological phenomenon called the Bystander Effect states that people are more likely to help someone in distress if there are few or no other witnesses. If there are more people around, one usually thinks someone else will stop to help. Scientists call this the diffusion of responsibility. The Bystander Effect was recently tested out on a busy London street and it turns out perceived social status plays a role in whether a person will receive help, but most people still continue on their way without stopping.


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 1950’s 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 once again showed that people tend to conform in group situations.


The Stanford Prison Experiment

standford prison

Considered to be one of the most unethical psychological experiments of all time, the Stanford Prison experiment studied the psychological effects a prison setting could have on behavior. In 1971, a mock prison was constructed in the basement of the psychology building of Stanford University and 24 male students were randomly selected to play the role of either a prisoner or prison guard for two weeks. The students adapted to their roles a little too well, becoming aggressive to the point of inflicting psychological torture. Even psychology professor Philip Zimbardo, who acted as superintendent of the experiment, proved susceptible to its effects by allowing the abuse to continue. The study was called off after only six days due to its intensity, but it proved that situations could provoke certain behaviors in spite of an individual’s natural tendencies.


The Bobo Doll Experiment

bobo doll

During the 1960’s, much debate arose about how genetics, environmental factors, or social learning shaped children’s development. Albert Bandura conducted the Bobo Doll Experiment in 1961 to prove that human behavior stemmed from social imitation rather than inherited genetic factors. He set up three groups: one was exposed to adults showing aggressive behavior towards a Bobo doll, another was exposed to a passive adult playing with the Bobo doll, and the third formed a control group. The results showed 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.


Pavlov’s Dogs


Does the name Pavlov ring a bell? If not, you’ve probably been living under a rock. This famous experiment made the concept of the conditioned reflex widespread. Pavlov examined the rate of salivation among dogs when presented with food. He noticed the dogs would salivate upon seeing their food, so he began ringing a bell every time the food was presented to the dogs. Over time, the dogs began to associate the ringing of the bell with food and would salivate upon hearing the bell, demonstrating that reflexes can be learned.


Little Albert


The Little Albert experiment is like the human equivalent of Pavlov’s dogs. Probably one of the most unethical psychological studies of all time, this experiment conducted in 1920 by John B. Watson and his partner Rosalie Rayner at Johns Hopkins University conditioned a nine-month-old boy to develop irrational fears. Watson began by placing a white rat in front of the infant, who showed no fear at first. He then produced a loud sound by striking a steel bar with a hammer every time little Albert touched the rat. After a while, 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 until Albert feared them all, proving that classical conditioning works on humans.


Carlsberg Social Experiment


In this hilarious advertisement turned social experiment, unsuspecting couples walked into a 150-seat movie theater filled with 148 bad-ass bikers and discovered that the only two empty seats were smack-dab in the middle. Some of the couples exited the theater to avoid having to shuffle past the bikers, but those who stayed were rewarded with Carlsberg beers and a whole lot of cheering. What would you do in that situation? Would you leave knowing your life would still be intact or trek your way to the middle of the theater and risk offending one of those intimidating guys? Just another reason why people shouldn’t judge based on appearances.


“Missing Child” Experiment

missing kids

People often fail to notice their surroundings, an idea that was put to the test during a missing child experiment. A flier with information and a picture about a “missing child” was posted on the doors of a busy store. Some people stopped to study the flier while others merely glanced at it or didn’t look at all. What all of these people had in common that they were completely oblivious of the fact that the boy on the flier was standing right in front of the store. This experiment demonstrates that humans tend to overlook a lot of the things around them.


A Class Divided


Inspired by the assassination of Dr. Martin Luther King Jr., third grade teacher Jane Elliott created an exercise in 1968 to help her white students understand the effects of racism. Elliott divided her class into two groups: blue-eyed students and brown-eyed students. On the first day, she designated the blue-eyed children as the superior group and gave them extra privileges, while the brown-eyed children represented the minority group. She discouraged the two groups from interacting and singled out students to emphasize the negative aspects of those in the minority group. She noticed immediate changes in the behavior of the children. Blue-eyed students performed better academically and some began bullying their brown-eyed classmates, while brown-eyed students 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 exercise, the children were so happy they embraced one another and agreed that people shouldn’t be judged based on outward appearances.


Harlow’s Monkeys

maternal bond

You can thank Harry Harlow for the amount of affection you received as a child. In a series of controversial experiments during the 1960’s, he revealed the importance of a mother’s love for healthy childhood development. Harlow separated rhesus monkeys from their mothers a few hours after birth and left them to be “raised” by two surrogate mothers. One mother was made of wire with an attached bottle for food; the other was made of soft terrycloth but lacked food. Interestingly, the baby monkeys spent much more time with the cloth mother than the wire mother, thus proving that affection plays a greater role than sustenance when it comes to childhood development.


Robbers Cave Experiment

two cabins

This classic study reminiscent of Golding’s Lord of the Flies is a classic example of prejudice and conflict resolution. 22 eleven-year old boys were randomly separated into two groups and taken to a summer camp in Robbers Cave State Park, Oklahoma. 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. When the two groups were introduced, they began to exhibit signs of verbal abuse. To increase the conflict between the groups, the experimenters made them compete against each other in a series of activities. More hostility ensued until the groups refused to even 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.


The Monster Study


Known as The Monster Study because of its unethical methods, this experiment determined the effects of positive and negative speech therapy on children. Wendell Johnson of the University of Iowa selected twenty-two orphan children, some with stutters and some without. He engaged the stutterers in positive speech therapy, praising them for their fluency, and the non-stutterers in negative speech therapy, belittling them for every mistake. 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.


Contagious Yawning


Everyone knows yawns can be contagious, but did you know dogs are capable of “catching” yawns too? A recent study conducted at the University of London found that 72 percent of dogs caught yawns after watching a person yawn. On average, it took the dogs 99 seconds to yawn and the dogs’ ages and genders did not affect yawning. Although why this happens remains a mystery, researchers think it may have something to do with a dog’s “capacity for empathy.”


The Halo Effect

happy couple

A classic finding in social psychology, the Halo Effect is the idea that our overall impression of a person can be based on one trait about them. For example, if someone has a likeable personality, people might find that person’s other qualities more appealing. In a recent experiment, a man made two videos for a dating website. In the first video, he read the script in an upbeat manner, whereas in the second, he read the same script in a more melancholy fashion. The first video was given to a one group of girls and the second was given to another group, who watched the video in a separate room. The girls who watched the upbeat video found the man to be likeable, while the girls who watched the second video found the man to be unpleasant, even though he had read the exact same script. Thus demonstrating the importance of tone in the perception of overall attractiveness and modeling the Halo Effect in action.


Identical Twins


For centuries, identical twins have fascinated psychologists. Multiple studies have been conducted in an effort to prove the existence of a psychic connection between them. In one experiment, TV personality Derren Brown tries to show that identical twins’ possess extrasensory communication skills. Whether or not a psychic connection really exists, the twins’ similar responses to sensory stimuli indicate that shared genes, upbringings, and life experiences may cause twins to develop similar thought processes.


Car Crash Experiment

crash test

Memories can be deceiving. This is what Loftus and Palmer discovered in their 1974 car crash experiment. The two wanted to see if wording questions a certain way would affect participants’ recall by distorting their memories of an event. The participants watched slides of a car accident and were asked to describe what had happened as if they were eyewitnesses. The experimenters found that the use of different verbs affected the participants’ memories of the accident, showing that memory can be easily distorted.


Cognitive Dissonance

cognitive dissonance

Have you ever suffered a disappointment and then convinced yourself that you weren’t disappointed at all? If you answered yes, you’ve experienced a psychological phenomenon called cognitive dissonance. In 1956, psychology student Jack Brehm brought some of his wedding gifts to class (a lamp, a toaster, a transistor radio, etc.) and asked everyone to rate each item’s desirability. The students were then asked to choose between two items they found equally attractive. After making a choice, the students were asked to rate all the items again. Everyone increased the ratings of the items they had chosen and downgraded the ratings of their second-choice items, showing that humans will always try to convince themselves that they’ve made the right decision.


Free Hugs Campaign

free hugs

We’ve all experienced bad days. Sometimes, a hug is all that we need to feel better. A man who called himself Juan Mann decided to conduct a social experiment of his own to test this theory. He stood in a busy area of Sydney, Australia, holding a sign that read “Free Hugs” and set out on a mission to spread joy in his hometown. His “Free Hugs” campaign elicited a tremendous response only to be banned by the police. But in an inspiring twist, over 10,000 people signed a petition to keep the campaign going, sending a hopeful message that humanity can be found even in this age of impersonal media and technology.


Change Blindness

change blindness

Change blindness is the inability to detect subtle changes in objects or scenes that would be perfectly obvious upon closer inspection. This unawareness can even include the recognition of human faces. One experiment revealed that visual distractions can cause change blindness. A man behind a counter handed a consent form to a subject. He then stooped down behind the desk to “retrieve a packet” only to have a different man emerge from behind the desk and give the packet to the subject. The second man in the experiment did not look like the first and was even wearing a different colored shirt. Astonishingly, 75 percent of subjects didn’t even notice the change, revealing how much the human brain misses from one moment to the next.


Candid Camera Elevator Social Experiment


Smile! You’re on Candid Camera. In this instance, innocent bystanders fall victim to a collective behavior experiment. The video shows the comical reactions to deviant social behavior in an elevator. Like most people, they conformed to the behavior of the group, even though they had no idea what was happening, revealing that individuals will always try to fit in even if they don’t understand the behavior of the group.

Photo: Featured Image - Teodorvasic97, Стенфорд, CC BY-SA 4.0, 1. Tiia Monto, Elevator in hotel, CC BY-SA 3.0 , 2. Globe_and_high_court.jpg: created by jjron Globe_and_high_court_fix.jpg: created by jjron, edited by Fir0002 derivative work: WikiCantona (talk), Globe and high court (Spot the difference), CC BY-SA 3.0 , 3. Jesse Steele from China, Taipei Sunflower Movement Free Hugs (13662057905), CC BY 2.0 , 4. Tesseract2, CognitiveDissonanceDiagram, CC BY-SA 3.0 , 5. Brady Holt, IIHS Hyundai Tucson crash test, CC BY 3.0 , 6. MirandaEm, Identical Twins, CC BY-SA 3.0 , 7. PxHere.com (Public Domain), 8. Juanedc from Zaragoza, España, Sueño (9215495371), CC BY 2.0 , 9. army.mil (Public Domain), 10. WikipediaCommons.com (Public Domain), 11. Koivth, MaternalBond, CC BY-SA 3.0 , 12. Pixabay.com (Public Domain), 13. Rattlenoun, Alicia Kozakiewicz at the National Center for Missing and Exploited Children, Alexandria, VA, CC BY-SA 4.0 , 14. Carterhawk, Dca muppet theater, CC BY-SA 3.0 , 15. WikipediaCommons.com (Public Domain), 16. Maxxl², Pavlov's dog conditioning, CC BY-SA 4.0 , 17. © Sémhur / Wikimedia Commons / CC-BY-SA-3.0, or Free Art License, Bobo doll-en, CC BY-SA 4.0 , 18. Teodorvasic97, Стенфорд, CC BY-SA 4.0 , 19. D-janous, Asch-Experiment, CC BY-SA 4.0 , 20. رمزي زودة, Bystander effect, CC BY-SA 3.0 , 21. WikipediaCommons.com (Public Domain), 22. Fred the Oyster, Milgram experiment v2, CC BY-SA 4.0 , 23. methodshop .com, Piano Stairs, CC BY-SA 2.0, 24. PublicDomainPictures.net (Public Domain), 25. Dave Morris, One of these things is not like the others, One of these things is not quite the same..., CC BY 2.0