Gross values: Investigating the role of disgust in bioethics

What is the role of disgust in moral judgements? Previous research found that disgust increases the severity of judgments; but other more recent work has cast doubt on these findings. Here we investigate roles of induced and trait disgust on moral judgments of controversial biological and medical technologies – bioethics – an area rife with proto-typical disgust cues. Participants (N = 600) viewed disgusting, frightening, or neutral pictures, rated the moral acceptability of biotechnologies, and completed questionnaire measures of trait disgust. We found a small negative effect of induced disgust (but not fear) on the acceptability of ‘existing’ biotechnology, but not ‘future’, ‘agricultural’, or ‘termination’ biotechnologies. But this effect was too small to change pre-existing opinions and would not have survived a correction for multiple tests. Although trait disgust had mostly negative relationships with the moral acceptability of biotechnologies, it did not moderate the effect of observing disgusting photos on biotechnology judgments. The larger, more consistent effects for trait disgust suggest that either (a) measures of trait disgust and moral attitudes share a source of method variance or (b) incidental, visual manipulations are too weak to capture the true effect of disgust on moral judgments.