Why Do We Explain the Same Behaviour Differently?

When a colleague arrives ten minutes late, we may immediately think, “He does not respect other people's time.” When we are late, we remember the roadworks, the missed green light and the unexpected phone call. This contrast is often described as the actor–observer bias: observers favour explanations based on character, while actors favour the situation.

The idea has intuitive support. Actors know their own goals, history and constraints, whereas observers first see the person and the visible behaviour. Different information can produce different explanations. The claim is also easily confused with the fundamental attribution error. That concept mainly concerns underestimating circumstances when judging another person; actor–observer asymmetry directly compares explanations of the same behaviour from the two roles.

It should not, however, be treated as a universal rule. Malle's 2006 meta-analysis of 173 studies found that the classic overall actor–observer difference was close to zero. More noticeable differences appeared under particular conditions, including negative events, hypothetical scenarios, close relationships and certain measurement methods. This does not show that people are always impartial. It shows that valence, self-defence, familiarity and the way a question is asked also shape explanations.

Lateness therefore cannot automatically diagnose a bias. A colleague may be habitually late, making disposition relevant; we may also have known that we needed to leave earlier, yet blame traffic for an avoidable delay. A better practice is to exchange the evidence available to each side. Before judging someone else, ask what circumstances could produce the behaviour. When judging yourself, ask which repeated choices were under your control. The aim is not to ban character explanations, but to require equally strong evidence for ourselves and others.

https://pubmed.ncbi.nlm.nih.gov/17073526/