The term shock experiment brings to mind ghastly images. Most of these experiments use animal participants and a level of shock that often is more startling than painful (like the shock we sometimes receive when exiting a car). Some shock experiments use human participants, but rather than shocking them, these experiments usually only lead people to believe they will receive a shock or will be delivering shocks to others. Even though these experiments carry a negative connotation, the conclusions drawn from some of them have had a significant impact on psychology and other disciplines. The three main areas in which shock experiments have been used are learning, emotion, and obedience.
Shock experiments are used to study learning (i.e., a change in behavior due to experience). Classical conditioning is a form of learning involving associations. Most humans and animals learn a behavior after being exposed to sequentially presented stimuli. For example, a researcher might expose a rat to a light and then deliver an electrical shock to its feet. Eventually, the rat will learn that the light is a signal for the shock; turning it on will cause the rat to behave in the same way it would if shocked. The rat has learned to associate shock with the light. Although this example is relevant, most shock experiments investigate the more complex aspects of learning.
Shock experiments are used to investigate emotions such as anger and moods such as depression. In a well–known set of experiments in the 1960s and 1970s, Martin Seligman (b. 1942) and colleagues used electrical shocks to study personal control and depression. In one experiment, Seligman delivered inescapable shocks to a group of dogs. Later, these dogs (and a control group of dogs not exposed to the inescapable shocks) were placed in a cage split in half by a barrier that could be jumped to reach the other side. When Seligman electrified one side of the floor, the dogs previously exposed to inescapable shocks were less likely than the control–group dogs to jump to the safe side of the cage. The dogs that failed to jump to safety had learned to be helpless and exhibited depressive–like symptoms.
This phenomenon was labeled learned helplessness. Experiments revealed that some humans also exhibit depressive–like symptoms when in uncontrollable situations (e.g., inescapable noise). The identification of learned helplessness was important in revealing the thought processes involved in depression. Researchers continue to study learned helplessness in humans and animals, and electrical shocks are routinely used in these experiments with animals (most often rats).
Stanley Milgram (1933–1984) made shock experiments infamous in the 1960s, leading people to equate psychology with shocking people. Milgram was interested in the conditions that foster obedience and disobedience. Obedience is the carrying out of a command given by a person of authority. Milgram’s interest in obedience was sparked partly by the Nazi atrocities, which spurred him to investigate to what extent ordinary people would harm an innocent person when ordered to.
Milgram studied 1,000 participants in several experiments. His basic experiment involved the use of a shock machine, an authority figure, and forty male participants who believed that the experiment was investigating punishment and memory. Participants were told that they would be required to deliver electrical shocks to a person in another room whenever he answered a question incorrectly, and they received sample shocks of 45 volts to convince them that the shock machine was real. The participant was told to increase the intensity of the shocks by 15 volts with each incorrect answer by flipping a switch on the machine, which had settings from 15 to 450 volts and ominous labels below the voltage readings (e.g., “slight shock,” “moderate shock,” “strong shock,” “very strong shock”). Although the participants were convinced that they were delivering painful shocks, in fact, the person in the other room was a confederate (i.e., an accomplice) who did not actually receive shocks. The authority figure, a stern man in a lab coat, ordered the participants to shock the confederate whenever an incorrect answer was given. At several points, the confederate complained of pain and asked to be released, eventually shouting “My heart’s starting to bother me now. Get me out of here, please. My heart’s starting to bother me. I refuse to go on. Let me out.”
Milgram was interested in determining the level at which participants would discontinue their obedience by refusing to deliver shocks. Of the participants in the experiment described here, 65 percent obeyed the order to deliver shocks up to 450 volts. These individuals obeyed even after the confederate stopped answering (presumably because he was incapacitated). This high level of obedience stunned Milgram and the world.
Milgram’s experiments are classics in psychology. His findings are provocative because they revealed the capacity ordinary people have for obeying destructive orders. Milgram’s use of deception, however, was considered unethical by many people. The participants believed they were inflicting harm, and many exhibited signs of extreme stress (e.g., trembling, sweating, biting of the lips, and stuttering). Critics contended that permanent harm was imposed on participants. Milgram countered critics by contacting many former participants; only 1 percent reported regret at having been in the experiment. Furthermore, a psychiatrist interviewed forty participants and found that none of them had suffered permanent harm.
The ethics of Milgram’s experiments are debatable. Nonetheless, his and other controversial experiments (e.g., the Tuskegee study) prompted changes in research standards. In 1974 the National Research Act became law. This act, along with guidelines written by the American Psychological Association, required that human and animal research be reviewed by Institutional Review Boards (IRBs), which ensure that no undue harm is done to humans or animals, and that humans voluntarily consent to participate. Although deception is allowed, the deception permitted by IRBs does not typically involve physical harm, but rather the mental discomfort that comes from being deceived.
Although it is certainly doubtful that an IRB would approve an experiment such as Milgram’s, shock experiments are routinely conducted on animals (and to a lesser extent on humans), but the level of shock typically used in these experiments is far from debilitating. In questioning the ethics of any experiment, one should consider the amount of pain inflicted and the knowledge to be gained before making definitive conclusions about the value of shock experiments.
SEE ALSO Ethics in Experimentation; Experiments; Experiments, Human; Milgram, Stanley
Milgram, Stanley. 1992. The Individual in a Social World: Essays and Experiments. 2nd ed. New York: McGraw–Hill.
Peterson, Christopher, Steven F. Maier, and Martin E. P. Seligman. 1993. Learned Helplessness: A Theory of the Age of Personal Control. New York: Oxford University Press.
Brian P. Meier