The exculpatory potential of moral ignorance: Evidence from a blame-updating paradigm

Recent debates have examined epistemic conditions on moral responsibility. A central question is whether ignorance of moral norms can excuse wrongdoing in the same way as factual ignorance. Volitionists link the exculpatory potential of moral ignorance to the fulfillment of procedural obligations. Quality of Will theorists add conditions such as inaccessibility of moral truth or high moral difficulty. In two pre-registered experiments (total N = 500), we tested whether procedural obligations, bias in moral evidence, and moral difficulty affect ascriptions of blame for everyday moral transgressions (act blameworthiness) and for moral ignorance about their wrongness (belief blameworthiness). Confirmatory analyses suggested that moral ignorance resulting from biased moral evidence slightly reduced both act and belief blameworthiness, and that the two types of blame were strongly correlated. High moral difficulty was associated with lower act and belief blameworthiness, but this was independent of any exculpatory effect of moral ignorance. Procedural obligations and their interaction with moral evidence did not show consistent effects on either type of blame. An exploratory analysis restricted to participants who had passed the respective manipulation checks suggested a moderate to large exculpatory effect of moral ignorance under fulfilled obligations combined with biased evidence. Yet, only one third of participants passed both manipulation checks for this combination. We interpret our results as suggesting that exculpation via moral ignorance is in principle possible, but many people are reluctant to accept that moral truth can be inaccessible to conscientious agents. We discuss implications for debates about epistemic conditions on moral responsibility.