Self-Perception Theory, proposed by Daryl Bem, suggests that people develop attitudes and opinions by observing their own behavior and drawing conclusions from it. This theory also downplays the role of internal thoughts and emotions in attitude formation.
Let’s say, for example, that you are a fan of classical music. According to self-perception theory, you didn’t decide that you like classical music because you think it’s the best type of music or because listening to it makes you feel good. You decided that you like classical music based on the fact that you listen to it a lot. Thus, we learn about ourselves and form self-judgments the same way we learn about and judge others – by observation.