Psychopathy and Moral Decision Making: A Data Reanalysis Exploration

Previous research found that people with higher level of psychopathy trait would endorse more to the harmful but beneficial action in traditional moral dilemmas. Three possibilities for this effect were confounded: People with higher psychopathy trait, 1) care more about the beneficial consequences; 2) care less about the “no harm” norms; 3) just prefer action irrespective of consequences and norms. A multinomial processing tree model named “CNI” was developed and claimed to dissociated these three possibilities. Four studies have applied CNI model to study the psychopathy-moral decision relationship. However, the CNI model presupposes the agent sequentially processes consequences-norms-generalized inaction/action preferences, which makes the estimated parameters biased and untenable. More recently, an alternative algorithm named “CAN” was developed based on the same data structure to overcome the limitations of CNI model. We applied CAN algorithm and reanalyzed the raw data of the four studies on psychopathy-moral decision relationship. The results demonstrated that people with higher psychopathy trait have weaker consequences and norms sensitivities, stronger overall action preferences, stronger inaction/action preferences irrespective of norms and consequences, and weaker moral principles obedience. Furthermore, the mediation and moderation reanalysis explorations demonstrated that instrumental harm and moral identity partly mediate the psychopathy-moral decision relationship and that perceived societal standards rather than personal standards when making moral decisions can alleviate the positive effects of psychopathy on overall action preference and action preference irrespective of norms and consequences. Present reanalysis exploration study clarified and deepened our insights on the relationship between psychopathy and moral decisions. Theoretical and methodological implications were also discussed.