Outcome effects, moral luck and the hindsight bias.

In a series of ten preregistered experiments (N = 2043), we investigate the effect of outcome valence on judgments of probability, negligence, and culpability - a phenomenon sometimes labelled moral (and legal) luck. We found that harmful outcomes, when contrasted with neutral outcomes, lead to an increased perceived probability of harm ex post, and consequently, to a greater attribution of negligence and culpability. Rather than simply postulating hindsight bias (as is common), we employ a variety of empirical means to demonstrate that the outcome-driven asymmetry across perceived probabilities constitutes a systematic cognitive distortion. We then explore three distinct strategies to alleviate the hindsight bias and its downstream effects on mens rea and culpability ascriptions. Not all strategies are successful, but some prove very promising. They should, we argue, be considered in criminal jurisprudence, where distortions due to the hindsight bias are likely considerable and deeply disconcerting.