Sentencing, severity, and social norms: a rank-based model of contextual influence on judgments of crimes and punishments.

Context effects have been shown to bias lay people's evaluations of the severity of crimes and punishments. To investigate the cognitive mechanisms behind these effects, we develop and apply a rank-based social norms approach to judgments of perceived crime seriousness and sentence appropriateness. In Study 1, we find that (a) people believe on average that 84% of people illegally download software more than they do themselves and (b) their judged severity of, and concern about, their own illegal software downloading is predicted not by its amount but by how this amount is believed (typically inaccurately) to rank within a social comparison distribution. Studies 2 and 3 find that the judged appropriateness of a given sentence length is highly dependent on the length of other sentences available in the decision-making context: The same objective sentence was judged as approximately four times stricter when it was the second longest sentence being considered than when it was the fifth longest. It is concluded that the same mechanisms that are used to judge the magnitude of psychophysical stimuli bias judgments about legal matters.