As psychology moved further away from philosophy and closer to science, more and more experiments began to be performed. These experiments have revealed important insights into the nature of human behavior. Some of these revelations are taken for granted in the modern world as his discoveries are now widely known. However, at the time, they were quite controversial.
The Stanford Prison Experiment
The Stanford Prison Experiment was conducted in August 1971 by Philip Zimbardo, a professor of psychology at Stanford University. The experiment was intended to examine the psychological impact of the prison environment on inmates and guards.
To test this, Zimbardo built a mock prison in the basement of Stanford University. A group of 24 participants were randomly assigned to the positions of guards or inmates with Zimbardo assuming the role of Prison Superintendent. All participants were screened beforehand and were considered to be “normal, healthy male college students who were efficiently middle-class and white.” Prisoners were taken from their homes, handcuffed by real police officers, and taken to the mock prison where they were stripped naked and deloused. The prisoners stayed in the prison 24 hours a day, while the guards only worked an eight-hour shift and returned home afterwards. All participants received $15 per day, funded in part by the US Navy.
The guards wore mirrored sunglasses, khaki uniform, baton and whistle, while the prisoners wore a smock with an identification number sewn on the front and back, a stocking cap and a chain attached to the ankles. The uniforms were designed to dehumanize the guards and prisoners while making it appear that the guards had complete control over the prisoners’ lives. The guards were instructed to “maintain a reasonable degree of order” but almost immediately began abusing their position. The guards forced the prisoners to perform exercises, stripped and degraded them, removed their mattresses and forced them to sleep on cement, and punished the prisoners by making them urinate and defecate in a bucket in their cells but not allow them to empty the bucket. They had truly immersed themselves in their role.
The experiment was supposed to last two weeks, but it ended after only 6 days. By that stage, five prisoners had already been released due to severe depression. Zimbardo himself became so immersed in his role as prison superintendent that he found that his ability to be impartial was severely impaired. Zimbardo had to be confronted by professor Christina Maslach (whom he would later marry) about the ethical problems of the experiment before realizing that he had failed in his duty to care for these young participants and ending the study. This experiment solidified Zimbardo’s idea that good people, if placed in bad environments, can be capable of great misdeeds. Zimbardo called this phenomenon “The Lucifer Effect”.
Milgram and obedience
After World War II, the surviving Nazis were tried for war crimes at the Nuremberg Trials. A common defense for them was to say that they were “just following orders.” Thus, Stanley Milgram, a psychologist at Yale University, devised an experiment to test whether anyone could be susceptible to this or whether Germans were unusually obedient to their superiors.
Milgram began the experiments in July 1961. He made a newspaper advertisement for male participants for an experiment on “learning”. There were three people involved: the experimenter, the teacher (participant), and the student (actor). The teacher and student would then be separated into different rooms where they can communicate but not see each other. The Master believed that the Apprentice’s cognitive abilities were being tested but in reality, it was the Master’s obedience to authority. Supposedly, the Apprentice was hooked up to electrodes and each time he gave an incorrect answer, the Master administered an electric shock that increased in severity with each incorrect answer. The shocks went from 15 volts (light) to 450 volts (death). The Master would receive a sample electrical shock before beginning to feel the pain caused to the Apprentice.
As the voltage increased, the intensity of the Apprentice’s screams also increased. If the Professor questioned the study at any time, the Experimenter gave 4 answers, continuing with the next each time he was asked. They were:
1: Please continue.
2: The experiment requires you to continue.
3: It is absolutely essential that you continue.
4: You have no choice but to continue.
About two-thirds of the participants continued with the lethal shock of 450 volts, while the rest continued with at least a very painful 300 volts. Milgram would go on to perform multiple separate variations of the experiment, changing the location, the proximity between student and teacher, etc. However, although proximity decreased the likelihood that participants would continue with 450 volts, 30% of participants still delivered lethal shocks. The experiment showed that ordinary people could commit acts of serious violence just because an authority figure ordered them to.
Asch and Compliance
In 1951, Solomon Asch conducted experiments at Swarthmore College. Asch recruited male college students to participate in tasks to measure their perceptual abilities. They would be shown a picture of one line followed by another picture with three lines labeled “A”, “B”, “C” and they would have to match the original line to the line of the same length in the second picture. The participants would sit around a table and take turns yelling their response. However, there was a catch: only one of them was actually a participant, the other participants were all actors, and the experiment was about examining group conformity, not perception.
This line task was repeated about 16 times with different lines each time. In the first two times, the participant and the actors gave the same correct answer. After this, the actors gave the same incorrect answer to see if the participant conformed to her answer despite knowing that she was correct.
In the end, 75% of participants gave at least one incorrect answer, 5% consistently complied with peer pressure, and 25% never complied. Those who conformed later stated that they did so out of doubt or low self-confidence with some feeling that their judgment must be affected, and therefore responded in agreement with the majority.
Harlow and attachment
In the 1950s, mainstream psychologists believed that classical conditioning was the basis of the bond between a mother and her child. The idea is that the child becomes attached to the mother because the mother feeds the child. During this time, John Bowlby disagreed. Instead, he believed that a mother and child have a unique bond that is more complicated than a conditioned response. Psychologist Harry Harlow began experiments on rhesus monkeys to test these hypotheses.
The experiments began with the isolation of baby rhesus monkeys. The monkeys were kept alone in isolation chambers for 3, 6, 12 and 24 months. This caused the monkeys to engage in strange behavior, such as rolling around in their cages or self-mutilating. When the monkeys were released and tried to integrate back into normal monkey populations, they had severe problems socializing. They were often bullied by the other monkeys. However, the monkeys demonstrated attachment to the cloth pads that covered the floor of the cage and exhibited tantrums if the cloths were removed.
After this, Harlow began to conduct a different type of experiment. Harlow and his students developed a surrogate mother for rhesus monkeys. The mother was a rubber-covered block of wood with soft cloth on the outside and a light bulb on the back to radiate heat. It was designed to be comfortable for monkeys. A second substitute was later developed, but it was just a bare and rather awkward wire. Both surrogates were placed in the cages of the baby monkeys, separated from each other. For four of the monkeys, the wire mother provided food and the cloth mother did not. For another four, the cloth mother provided food and the wire mother did not.
Harlow found that all the monkeys spent most of their time in the cloth mother. Those who were fed by the wire mother only let the cloth mother feed and those who were fed by the cloth mother hardly ever visited the wire mother. Also, when frightened, the monkeys almost always ran towards the cloth mother instead of the wire mother. These findings demonstrate that the comfort of contact is essential for the formation of a strong mother-infant bond. This runs counter to the behavioral viewpoint which held that this attachment was the result of the mother feeding the child.
These experiments changed the fabric of modern psychology. They introduced new theories that challenged the current paradigm and made Psychology introduce ethical evaluation methods after witnessing the negative effect of careless psychological evaluation. Each of these psychologists made contributions to their respective fields that have gone down in history. So, to all the budding psychologists: go out there and make history.
References
Asch, SE (1951). Effects of group pressure on the modification and distortion of judgment. In H. Guetzkow (ed.) Groups, leadership and men. Pittsburgh, Pennsylvania: Carnegie Press.
Bowlby, J. (1958). The nature of the child’s bond with his mother. International Journal of Psychoanalysis, 39, 350-371.
Haney, C., Banks, W. C., and Zimbardo, P. G. (1973). A study of prisoners and guards in a simulated prison. Naval Research Journal, 30, 4-17.
Harlow, H. F. and Zimmermann, R. R. (1958). The development of affective responsiveness in infant monkeys. Proceedings of the American Philosophical Society, 102,501-509.
Milgram, S. (1963). Behavioral study of obedience. Journal of Social and Abnormal Psychology, 67, 371-378.