Aronson, E. & Mills, J. (1959). The effect of severity of initiation on liking for a group. Journal of Abnormal and Social Psychology, 59, 177-181.
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Aronson and Mills applied Festinger's theory of cognitive dissonance (the process by which people change their attitudes or behavior to be consistent with one another) to the observation that when people experience a great deal of trouble or pain attaining something, they tend to value it more than if they had no trouble attaining it. Results were consistent with their hypothesis: participants who underwent a severe initiation to join a group expressed more liking toward the group than participants who underwent a mild or no initiation. They reasoned that the severity of the initiation created dissonance between the cognition that one experienced the unpleasantness of the initiation in order to gain admission to the group and the cognition that there are things that one does not like about the group. To resolve this dissonance, participants could either downplay the unpleasantness of the initiation or exaggerate their fondness of the group. The more severe the initiation, however, the more difficult it is to convince oneself that it was not unpleasant. Thus, participants who experienced the severe initiation expressed more liking for the group than participants who experienced a mild or no initiation.
This article is a classic in social psychology because it challenged behaviorism and the notion that people are motivated solely by reward and punishment. It used controlled experimental procedures and provided evidence in support of the influential theory of cognitive dissonance.
For more on this topic
Festinger, L. (1957). A theory of cognitive dissonance. Oxford, England: Row, Peterson.