Final answer:
The biggest difference between Festinger and Bem is that Festinger focused on cognitive dissonance, while Bem focused on self-perception theory.
Step-by-step explanation:
The biggest difference between Festinger and Bem is that Festinger focused on cognitive dissonance, while Bem focused on self-perception theory. Festinger's theory of cognitive dissonance states that when we experience a conflict in our behaviors, attitudes, or beliefs that runs counter to our positive self-perceptions, we experience psychological discomfort. On the other hand, Bem's self-perception theory suggests that people acquire their attitudes and beliefs by observing their own behavior and the circumstances under which it occurs.