Actor-observer bias

Meaning: Attribution theory describes how people explain behavior, either as dispositional (internal traits, motives, attitudes) or situational (external circumstances). Actor-observer bias is the tendency to explain our own actions, as the actor, with the situation, but to explain the same action by someone else, as the observer, with that person's disposition. One account is that actors see the pressures around them and know their own behavior varies across settings, while observers focus attention on the person and know less about the context.

On the MCAT: A vignette describes someone who is late and blames traffic, then sees a coworker arrive late and calls the coworker irresponsible. You name the bias or predict which kind of attribution each person makes. Answer choices often place it beside other attribution concepts, so you must separate them.

Common confusion: Students mix it up with self-serving bias. Self-serving bias depends on the outcome: people tend to credit their successes to their own disposition and blame their failures on the situation. Actor-observer bias depends on whose behavior is being explained, self or other. It is also not the same as the fundamental attribution error, which is the observer half only: overestimating disposition when explaining others. Actor-observer bias adds the contrast with how we explain ourselves.