Contrast A More Parsimonious Account of Cognitive Dissonance Effects

When humans expend great energy to achieve a goal they generally appreciate the results more than if hard work is not necessary. This phenomenon, known as justification of effort, is a form of cognitive dissonance reduction (an attempt to alleviate the discomfort resulting from conflict between beliefs and behavior). But the fact that pigeons too show a preference for a stimulus (associated with food) that follows greater effort over a different stimulus (also associated with food) that follows less effort suggests that a simpler behavioral mechanism is involved. We have proposed a simpler mechanism based on contrast between the end of the effort and the reinforcement (or the signal for reinforcement) that follows. This model predicts that any relatively aversive event can be used to enhance the value of the reinforcer that follows it. In support of this general model, we have found this effect in pigeons when the prior event consists of more rather than less effort (pecking), a long rather than a short delay, and the absence of food rather than food. We have also found that a pigeon's preference for food at one location can shift towards a different location if acquiring food at the new location requires that the pigeon work harder to obtain food there. Contrast may also play a role in other social psychological phenomena that have been interpreted as cognitive dissonance effects.