“It’s wrong but I can’t explain why!” Moral dumbfounding and moral judgement: how failure to justify moral judgements can inform our understanding of how they are made

Abstract

Moral dumbfounding occurs when people fail to justify a strongly held moral judgement with supporting reasons. The discovery of moral dumbfounding coincided with a growth in intuitionist and dual-process theories of moral judgement over rationalist theories, and its existence has directly informed their development (e.g., Haidt, 2001; Prinz, 2005; Bucciarelli, Khemlani, & Johnson-Laird 2008; Dwyer, 2009; Cushman, Young, & Greene 2010). Despite the influence of moral dumbfounding on the morality literature, the phenomenon is poorly understood. Direct evidence in support of dumbfounding is limited to a single study (Haidt, Björklund, & Murphy, 2000), which had a final sample of 30 participants and was never published in peerreviewed form. The aim of the current project is to examine the phenomenon of moral dumbfounding directly, firstly, to test if it is a real phenomenon, and secondly to evaluate how the existence (or absence) of moral dumbfounding can inform theories of moral judgement. Three studies demonstrate that dumbfounding is a genuine phenomenon that can be reliably elicited in a laboratory setting, and develop methods for studying dumbfounding. Two studies address specific challenges to dumbfounding, and demonstrate that (a) people do not reliably articulate reasons that may be governing their judgement, and (b) moral principles are not consistently applied across differing contexts. A final set of studies tested two hypothesised explanations of moral dumbfounding associated with dual-process theory (e.g., Cushman, 2013; Crockett, 2013), and model theory (Bucciarelli et al., 2008). Using a range of manipulations across seven studies, the observed evidence for these explanations is weak. That dumbfounding is poorly explained by existing theories of moral judgement presents a significant limitation of current theories of moral judgement. To address this limitation, a possible alternative theoretical approach that provides an explanation for moral dumbfounding is explored.