They should have known better: The roles of negligence and outcome in moral judgements of accidental actions.

Two experiments were conducted to investigate the relative influence of agents' negligence and their actions' unintended outcomes on moral judgements. In Study 1, 343 participants were asked in an online questionnaire about a driver whose level of negligence, and the severity of the outcome, were varied systematically. Each judged how much punishment and blame the driver deserved, and rated her negligence, causal responsibility, and intentionality. In Study 2, 341 participants completed the same questionnaire, and also judged the driver's wrongness and the outcome's severity. In both studies, judgements were strongly influenced by negligence; blame was also affected by causal responsibility, and wrongness by intention, but the relatively slight outcome effect on blame and wrongness was largely mediated by negligence. In contrast, both negligence and outcome had substantial effects on punishment judgements; most participants assigned high levels of punishment when, and only when, the outcome was negative and the agent was negligent. These findings shed light on the intriguing phenomenon of moral luck, and indicate that it applies more to punishment judgements than to blame and wrongness. They also indicate that when no negligence information is provided in the description of accidents (as in many previous studies), participants often attribute negligence to agents and judge them accordingly. It seems that the effect of outcome on moral judgements has often been overestimated by researchers, and that of negligence underestimated.