Moral Judgment and the Brain: The Role of the Frontal Lobes and the Moderating Influence of Mortality Salience and Type of Moral Dilemma on Moral Judgment

Abstract

Moral psychology has been an area of study advanced by philosophers and political scientists for the most part of its history. Although various psychological attempts have been made to study moral decision-making and development, mainly by Piaget and Kohlberg, nonetheless morality as a topic remained at the fringes of psychology. The last 20 years saw the development of moral psychological theories that were informed by the latest neuropsychological developments of brain translational recording technologies. Specifically, two theories appeared: the social intuitive theory and the dual processing theory. The current study sought to investigate the validity of the dual processing theory utilizing EEG technology, while also introducing mortality reminders as an experimental condition affecting moral judgment. The current study used a mixed factorial within-between cross-over experimental design wherein all participants were initially quasi-randomly assigned to a group were they were first presented with the push or switch moral dilemma and then, after the introduction of a prime, were given the other dilemma (e.g., push group did switch dilemma; switch group did push dilemma). All participants received both moral dilemma conditions. In the case of the prime, there were two prime conditions- mortality salience and neutral conditions. Participants were quasi-randomly assigned to a prime condition. The dependent/outcome variables were type of moral judgment, moral reasoning, and brain activity operationalized in terms of absolute power across all spectral frequencies measured. The results of the current study showed small support for the existence of two types of moral judgments (deontological vs. utilitarian) in response to two different types of moral dilemmas (personal vs. impersonal). However, the study did not find support for the assertion that utilitarian judgments were moderated by increased activity in the DLPFC, while the deontological judgments were moderated by increased activity in the VMPFC. The study also did not find support for the effect of heightened anxiety induced via mortality salience on types of moral judgments. Implication for these results, limitations, and directions for future research are further discussed.