The actor-observer bias is the phenomenon of attributing one's own behavior to external, situational forces, while attributing other people's behavior to internal, dispositional factors. This difference in attribution occurs because as 'actors,' we possess more information about the situational context influencing our actions. Conversely, as 'observers,' we lack this detailed information about others' circumstances, which causes us to default to a dispositionist perspective and commit the fundamental attribution error when judging their behavior.