Attribution theory

Attribution theory describes how people explain why others — and they themselves — behave as they do. Every explanation falls into one of two broad categories: a dispositional (internal) attribution credits the person's character, personality, or ability, while a situational (external) attribution credits the circumstances. If a driver cuts you off, deciding "they're a reckless jerk" is dispositional; deciding "they must be rushing to an emergency" is situational.

The theory's most tested idea is the fundamental attribution error: when explaining other people's behavior, we systematically overweight dispositional causes and underweight situational ones. A student who watches a classmate fail a test tends to assume low ability rather than a sick child at home or an unfair exam. The bias flips for our own behavior in the actor-observer effect — we explain our own actions situationally ("I was tired") while explaining others' actions dispositionally ("they're careless").

A related pattern, the self-serving bias, protects self-esteem: people attribute their successes to internal causes (talent, effort) and their failures to external ones (bad luck, unfair conditions). Together these biases shape how we judge others, assign blame, and interpret social conflict — which is why attribution theory anchors the study of person perception and attitudes in social psychology.

The AP Psychology exam tests attribution theory in its social psychology unit. Be ready to label examples as dispositional or situational, identify the fundamental attribution error, actor-observer effect, and self-serving bias in scenarios, and connect attributions to person perception.