Why you're 'having a bad day' but they're just a jerk

Someone cuts you off in traffic and you think: what a reckless idiot. But when you cut someone off, it's because you were late, the sign was hidden, the sun was in your eyes. This lopsided reasoning has a name: the fundamental attribution error — our habit of explaining other people's behavior by their character while excusing our own by our circumstances.

Psychologists call the two explanations dispositional (it's who they are) and situational (it's the situation they're in). The bias is that for others we over-reach for disposition and underweight the situation — even when the situation is staring us in the face. In a classic demonstration, people read essays that a student was told which side to argue, yet observers still assumed the essay reflected the writer's true beliefs.

The asymmetry exists partly because of perspective: you can see the pressures acting on you, but you only see other people's actions, not the invisible forces pushing on them. So their behavior looks like pure personality. Notice this and a lot of everyday anger softens — the 'rude' waiter may be drowning in tables, not born unpleasant.