Response to Greene: moral sentiments and reason: friends or foes?

Abstract

The behavioral patterns observed in patients with ventromedial prefrontal cortex (VMPFC) damage, characterized by increased utilitarian choices in moral dilemmas alongside heightened punishment of non-cooperators in economic games, challenge both the dual-process model of moral judgment and the hypothesis of general emotional blunting. While these patients appear more rational in personal dilemmas, their behavior in social exchange suggests preserved or even exaggerated emotional responses. This apparent paradox is best resolved through a functional dissociation within the moral sentiment domain rather than a competition between cognitive and emotional systems. Specifically, the VMPFC and frontopolar cortex mediate prosocial sentiments such as guilt and compassion, whereas the ventrolateral prefrontal cortex supports the experience of anger and indignation. Under this framework, VMPFC lesions selectively impair prosocial emotions, facilitating utilitarian outcomes through a lack of empathic concern rather than an enhancement of abstract reasoning. Furthermore, the posterior dorsolateral prefrontal regions often associated with utilitarian control appear to support general executive functions and working memory rather than specific moral-cognitive mechanisms. Consequently, the utilitarian tendencies of VMPFC patients represent a selective deficit in the internal motivations that drive prosocial behavior, highlighting a significant divergence between observable moral choice and underlying emotional sentiment. – AI-generated abstract.