Experimental research is research that involves using a scientific approach to examine research variables.
Below are some famous experimental research examples. Some of these studies were conducted quite a long time ago. Some were so controversial that they would never be attempted today. And some were so unethical that they would never be permitted again.
A few of these studies have also had very practical implications for modern society involving criminal investigations, the impact of television and the media, and the power of authority figures.
Examples of Experimental Research
1. Pavlov’s Dog: Classical Conditioning
Dr. Ivan Pavlov was a physiologist studying animal digestive systems in the 1890s. In one study, he presented food to a dog and then collected its salivatory juices via a tube attached to the inside of the animal’s mouth.
As he was conducting his experiments, an annoying thing kept happening; every time his assistant would enter the lab with a bowl of food for the experiment, the dog would start to salivate at the sound of the assistant’s footsteps.
Although this disrupted his experimental procedures, eventually, it dawned on Pavlov that something else was to be learned from this problem.
Pavlov learned that animals could be conditioned into responding on a physiological level to various stimuli, such as food, or even the sound of the assistant bringing the food down the hall.
Hence, the creation of the theory of classical conditioning. One of the most influential theories in psychology still to this day.
2. Bobo Doll Experiment: Observational Learning
Dr. Albert Bandura conducted one of the most influential studies in psychology in the 1960s at Stanford University.
His intention was to demonstrate that cognitive processes play a fundamental role in learning. At the time, Behaviorism was the predominant theoretical perspective, which completely rejected all inferences to constructs not directly observable.
So, Bandura made two versions of a video. In version #1, an adult behaved aggressively with a Bobo doll by throwing it around the room and striking it with a wooden mallet. In version #2, the adult played gently with the doll by carrying it around to different parts of the room and pushing it gently.
After showing children one of the two versions, they were taken individually to a room that had a Bobo doll. Their behavior was observed and the results indicated that children that watched version #1 of the video were far more aggressive than those that watched version #2.
Not only did Bandura’s Bobo doll study form the basis of his social learning theory, it also helped start the long-lasting debate about the harmful effects of television on children.
Worth Checking Out: What’s the Difference between Experimental and Observational Studies?
3. The Asch Study: Conformity
Dr. Solomon Asch was interested in conformity and the power of group pressure. His study was quite simple. Different groups of students were shown lines of varying lengths and asked, “which line is longest.”
However, out of each group, only one was an actual participant. All of the others in the group were working with Asch and instructed to say that one of the shorter lines was actually the longest.
Nearly every time, the real participant gave an answer that was clearly wrong, but the same as the rest of the group.
The study is one of the most famous in psychology because it demonstrated the power of social pressure so clearly.
4. Car Crash Experiment: Leading Questions
In 1974, Dr. Elizabeth Loftus and her undergraduate student John Palmer designed a study to examine how fallible human judgement is under certain conditions.
They showed groups of research participants videos that depicted accidents between two cars. Later, the participants were asked to estimate the rate of speed of the cars.
Here’s the interesting part. All participants were asked the same question with the exception of a single word: “How fast were the two cars going when they ______into each other?” The word in the blank varied in its implied severity.
Participants’ estimates were completely affected by the word in the blank. When the word “smashed” was used, participants estimated the cars were going much faster than when the word “contacted” was used.
This line of research has had a huge impact on law enforcement interrogation practices, line-up procedures, and the credibility of eyewitness testimony.
5. The 6 Universal Emotions
The research by Dr. Paul Ekman has been influential in the study of emotions. His early research revealed that all human beings, regardless of culture, experience the same 6 basic emotions: happiness, sadness, disgust, fear, surprise, and anger.
In the late 1960s, Ekman traveled to Papua New Guinea. He approached a tribe of people that were extremely isolated from modern culture. With the help of a guide, he would describe different situations to individual members and take a photo of their facial expressions.
The situations included: if a good friend had come; their child had just died; they were about to get into a fight; or had just stepped on a dead pig.
The facial expressions of this highly isolated tribe were nearly identical to those displayed by people in his studies in California.
6. The Little Albert Study: Development of Phobias
Dr. John Watson and Dr. Rosalie Rayner sought to demonstrate how irrational fears were developed.
Their study involved showing a white rat to an infant. Initially, the child had no fear of the rat. However, the researchers then began to create a loud noise each time they showed the child the rat by striking a steel bar with a hammer.
Eventually, the child started to cry and feared the white rat. The child also developed a fear of other white, furry objects such as white rabbits and a Santa’s beard.
This study is famous because it demonstrated one way in which phobias are developed in humans, and also because it is now considered highly unethical for its mistreatment of children, lack of study debriefing, and intent to instil fear.
7. A Class Divided: Discrimination
Perhaps one of the most famous psychological experiments of all time was not conducted by a psychologist. In 1968, third grade teacher Jane Elliott conducted one of the most famous studies on discrimination in history. It took place shortly after the assassination of Dr. Martin Luther King, Jr.
She divided her class into two groups: brown-eyed and blue-eyed students. On the first day of the experiment, she announced the blue-eyed group as superior. They received extra privileges and were told not to intermingle with the brown-eyed students.
They instantly became happier, more self-confident, and started performing better academically.
The next day, the roles were reversed. The brown-eyed students were announced as superior and given extra privileges. Their behavior changed almost immediately and exhibited the same patterns as the other group had the day before.
This study was a remarkable demonstration of the harmful effects of discrimination.
8. The Milgram Study: Obedience to Authority
Dr. Stanley Milgram conducted one of the most influential experiments on authority and obedience in 1961 at Yale University.
Participants were told they were helping study the effects of punishment on learning. Their job was to administer an electric shock to another participant each time they made an error on a test. The other participant was actually an actor in another room that only pretended to be shocked.
However, each time a mistake was made, the level of shock was supposed to increase, eventually reaching quite high voltage levels. When the real participants expressed reluctance to administer the next level of shock, the experimenter, who served as the authority figure in the room, pressured the participant to deliver the next level of shock.
The results of this study were truly astounding. A surprisingly high percentage of participants continued to deliver the shocks to the highest level possible despite the very strong objections by the “other participant.”
This study demonstrated the power of authority figures.
9. The Marshmallow Test: Delay of Gratification
The Marshmallow Test was designed by Dr. Walter Mischel to examine the role of delay of gratification and academic success.
Children ages 4-6 years old were seated at a table with one marshmallow placed in front of them. The experimenter explained that if they did not eat the marshmallow, they would receive a second one. They could then eat both.
The children that were able to delay gratification the longest were rated as significantly more competent later in life and earned higher SAT scores than children that could not withstand the temptation.
The study has since been conceptually replicated by other researchers that have revealed additional factors involved in delay of gratification and academic achievement.
10. Stanford Prison Study: Deindividuation
Dr. Philip Zimbardo conducted one of the most famous psychological studies of all time in 1971. The purpose of the study was to investigate how the power structure in some situations can lead people to behave in ways highly uncharacteristic of their usual behavior.
College students were recruited to participate in the study. Some were randomly assigned to play the role of prison guard. The others were actually “arrested” by real police officers. They were blindfolded and taken to the basement of the university’s psychology building which had been converted to look like a prison.
Although the study was supposed to last 2 weeks, it had to be halted due to the abusive actions of the guards.
The study demonstrated that people will behave in ways they never thought possible when placed in certain roles and power structures. Although the Stanford Prison Study is so well-known for what it revealed about human nature, it is also famous because of the numerous violations of ethical principles.
The studies above are varied and focused on many different aspects of human behavior. However, each example of experimental research listed above has had a lasting impact on society. Some have had tremendous sway in how very practical matters are conducted, such as criminal investigations and legal proceedings.
Psychology is a field of study that is often not fully understood by the general public. When most people hear the term “psychology,” they think of a therapist that listens carefully to the revealing statements of a patient. The therapist then tries to help their patient learn to cope with many of life’s challenges. Nothing wrong with that.
In reality however, most psychologists are researchers. They spend most of their time designing and conducting experiments to enhance our understanding of the human condition.
Asch SE. (1956). Studies of independence and conformity: I. A minority of one against a unanimous majority. Psychological Monographs: General and Applied, 70(9),1-70. https://doi.org/doi:10.1037/h0093718
Bandura A. (1965). Influence of models’ reinforcement contingencies on the acquisition of imitative responses. Journal of Personality and Social Psychology, 1(6), 589-595. https://doi.org/doi:10.1037/h0022070
Beck, H. P., Levinson, S., & Irons, G. (2009). Finding little Albert: A journey to John B. Watson’s infant laboratory. American Psychologist, 64(7), 605-614.
Ekman, P. & Friesen, W. V. (1971). Constants Across Cultures in the Face and motion. Journal of Personality and Social Psychology, 17(2), 124-129.
Loftus, E. F., & Palmer, J. C. (1974). Reconstruction of automobile destruction: An example of
the interaction between language and memory. Journal of Verbal Learning and Verbal
Behavior, 13(5), 585–589.
Milgram S (1965). Some Conditions of Obedience and Disobedience to Authority. Human Relations, 18(1), 57–76.
Mischel, W., & Ebbesen, E. B. (1970). Attention in delay of gratification. Journal of Personality and Social Psychology, 16(2), 329-337.
Pavlov, I.P. (1927). Conditioned Reflexes. London: Oxford University Press.
Watson, J. & Rayner, R. (1920). Conditioned emotional reactions. Journal of Experimental Psychology, 3, 1-14. Zimbardo, P., Haney, C., Banks, W. C., & Jaffe, D. (1971). The Stanford Prison Experiment: A simulation study of the psychology of imprisonment. Stanford University, Stanford Digital Repository, Stanford.
Dr. Chris Drew is the founder of the Helpful Professor. He holds a PhD in education and has published over 20 articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education. [Image Descriptor: Photo of Chris]