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 increased perceived probability of harm ex post, and consequently to increased attribution of negligence and culpability. Rather than simply postulating a 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 are successful, but at least some prove promising. They should, we argue, be taken into consideration in criminal jurisprudence, where distortions due to the hindsight bias are likely considerable and deeply disconcerting.The practical problem, however, must be taken seriously: In everyday life, we are not confronted with two neat cases side-by-side. Usually, we assess situations where a concrete harm has occurred and here outcome is likely to have a distorting effect on our judgment, violating the Control Principle to which both the Law and the Folk are committed.
The Mechanics of the Outcome EffectHow can we alleviate the outcome effect? This depends, in parts, on its more intricate mechanics. There is some evidence in favour of a probabilistic account of moral luck-type phenomena (Kamin & Rachlinski, 1995;Kneer & Machery, 2019). On this account, the post-hoc probability of harming a child is perceived higher for Frank than for Su. It thus seems more appropriate to judge that Frank incurred a substantial risk than that Su did, which, in turn would mean he was more reckless or negligent than Su. 1 If this account is on the right track, then a perceived difference in probability and risk drives an asymmetry of risk-related inculpating mental states and hence moral (and legal) evaluation (see Figure 1). The whole series of inferences from descriptive features to normative evaluation is innocuous, except for the first step, which is affected by the hindsight bias: in Frank's case, people tend to exaggerate the degree to which a harmful outcome could, or should, have been anticipated (Fischhoff, 1975;1980). To address the distorting effect of outcome on culpability judgments, this suggests, we must find ways to alleviate the hindsight bias -which is the topic of the paper.The paper proceeds as follows: We first explore whether the probabilistic account of the effect of outcome on culpability replicates (section 2). Our experiments are the first to control explicitly for the distinction between objective probability (probability from the perspective of the universe) and subjective probability (as perceived from the agent's context). Having replicated the outcome effect on probability, mens rea and moral judgment, we show -rather than jus...
