A psychology experiment was conducted to test the placebo effect.
Latin for “I will please”, the word placebo and the placebo effect means just that. Commonly used in research, a placebo is an inactive substance that would otherwise have no effect. However, because of the power of suggestion, when told that the placebo has an effect, the subjects receiving the placebo will believe and report that it does. This results in the placebo effect. Although placebos and the placebo effect are often spoken of in the context of medicine, occurrences of placebos and its effect have been commonly observed outside of medicine (Carroll). The placebo effect has been known for many years and numerous experiments have been conducted to test its power.
E. Morton Jellinek, Sc. D., conducted one of the most well-known experiments concerning the placebo effect in 1946. Jellinek set up a trial involving 199 subjects (originally 200) to test three different drugs: drugs A, B, and C. Drug D was also placed amongst these as a placebo. The design of the experiment was different from older experiments involving placebos in that older experiments used placebos to “express the efficacy or non-efficacy of a drug in terms of “how much better.” The subjects suffered from frequent headaches and were divided into four test groups. Jellinek had each group take all four drugs, though the order between the groups was different. In the end, 120 of the 199 subjects responded to the placebo and the experiment proved to be another example of the power of the placebo (Jellinek 87-91) .
As mentioned earlier, the placebo effect present not only in medicine. An experiment set out to measure the response of humans when under the influence of alcohol is a famous example. Some subjects were given successive doses of alcohol and their responses were measured after each dose. Other subjects were instead given a placebo meant to mimic the taste of alcohol and it was suggested to these subjects that what they was drinking was indeed alcohol. As expected, the group that was given actual alcohol exhibited signs of drunkenness and lack of coordination. What was surprising was that the placebo group exhibited the same signs, with some even seeming drunk. It seemed that the mere suggestion of drinking alcohol produced inebriated behavior (Henderson).
Scientists generally agree that for the placebo effect to occur, the subject must believe that he is given effective treatment and that it must be suggested to him that the treatment is effective. The question of how and why placebo responses are generated is still a matter of debate and three well-known theories have been proposed, though these three are not necessarily mutually exclusive. The first theory argues that the placebo effect is the result of the subject-expectancy effect: subjects will expect a given result and will therefore report that result. Another theory argues that it is the result of classical conditioning. Proponents of this theory explain that people are conditioned to associate a particular stimulus with a particular response. With confronted with a stimulus of a placebo that is perceived to be medicine, subjects will give off the appropriate response, which is relief. The last theory proposes that motivation to feel better and cooperate with an experimenter to be the ultimate cause (Carroll).