Final answer:
Self-perception theory states that people change their attitudes by inferring them from their own behavior. Cognitive dissonance leads to internal attitude changes when inconsistencies between behaviors, attitudes, or beliefs cause psychological discomfort. External attitude changes occur through persuasion, either via central or peripheral routes.
Step-by-step explanation:
According to self-perception theory, people internally change their attitudes because they infer their attitudes from their behavior. This is an internal process where individuals assess their actions and the circumstances under which they occur, leading to conclusions about their beliefs and feelings. When people engage in a behavior, they then look to that behavior to infer their own attitudes as if they were observing someone else.
Cognitive dissonance is another internal process that leads to attitude change. When there is an inconsistency between attitudes, behaviors, or beliefs, it creates psychological discomfort, prompting an individual to change one or more of these elements to reduce the dissonance and achieve consonance and self-consistency.
External attitude changes occur through persuasion. This persuasion can take one of two primary routes: the central route, which involves changing attitudes through a rational cognitive process by presenting facts and information; and the peripheral route, which uses emotional appeal or the association of the attitude object with positive cues, such as beauty or fame.