Norm theory
We judge each event against the alternatives it spontaneously evokes.
What it means
Norm theory holds that reactions to an event depend not on its absolute properties but on a reference set of counterfactual alternatives the event itself calls to mind after the fact. An outcome that is easy to mentally undo — because more 'normal' alternatives spring readily to mind — provokes stronger affect, stronger causal attribution, and more regret. Norms are computed on the fly by blending the actual event with its summoned counterparts, so abnormality and surprise are post-hoc, comparative judgments rather than fixed traits. The theory unifies findings on emotional amplification, the abnormality bias in causal reasoning, and why exceptional circumstances loom large. It is the conceptual engine behind much counterfactual and regret research.
Examples
A victim hurt while taking an unusual route home is seen as more unlucky, and the event as more poignant, than identical harm on the everyday route.
Two passengers miss the same flight, one by half an hour and one by two minutes. The near-miss stings far more, because the version where he made it springs so readily to mind.
Someone injured on a shift they picked up as a one-off favour is pitied more than a colleague hurt on their usual shift — the world where they stayed home is right there.
First described in Kahneman & Miller (1986).