Self-perception Theory - Disproof of Self-Perception Theory?

Disproof of Self-Perception Theory?

There was a time when it was debated whether or not dissonance or self perception was the valid mechanism behind attitude change. The chief difficulty was in finding an experiment where the two flexible theories would make distinctly different predictions. Some prominent social psychologists such as Anthony Greenwald thought it would be impossible to distinguish between the two theories.

In 1974, Zanna and Cooper conducted an experiment in which individuals were made to write a counter-attitudinal essay. They were divided into either a low choice or a high choice condition. They were also given a placebo; they were told the placebo would induce either tension, relaxation, or exert no effect.

Under low choice, all participants exhibited no attitude change, which would be predicted by both cognitive dissonance theory and self-perception theory.

Interestingly, under high choice, participants who were told the placebo would produce tension exhibited no attitude change, and participants who were told the placebo would produce relaxation demonstrated larger attitude change.

These results are not explainable by self-perception theory as arousal should have nothing to do with the mechanism underlying attitude change. Cognitive dissonance theory, however, was readily able to explain these results: if the participants could attribute their state of unpleasant arousal to the placebo, they wouldn't have to alter their attitude.

Thus, for a period of time, it seemed the debate between self-perception theory and cognitive dissonance had ended.