The neuroscience of morality and social decision-making

ABSTRACT

Across cultures humans care deeply about morality and create institutions, such as criminal courts, to enforce social norms. In such contexts, judges and juries engage in complex social decision-making to ascertain a defendant’s capacity, blameworthiness, and culpability. Cognitive neuroscience investigations have begun to reveal the distributed neural networks which interact to implement moral judgment and social decision-making, including systems for reward learning, valuation, mental state understanding, and salience processing. These processes are fundamental to morality, and their underlying neural mechanisms are influenced by individual differences in empathy, caring and justice sensitivity. This new knowledge has important implication in legal settings for understanding how triers of fact reason. Moreover, recent work demonstrates how disruptions within the social decision-making network facilitate immoral behavior, as in the case of psychopathy. Incorporating neuroscientific methods with psychology and clinical neuroscience has the potential to improve predictions of recidivism, future dangerousness, and responsivity to particular forms of rehabilitation.

KEYWORDS:

• Empathy
• justice motivation
• morality
• neuroscience
• social decision-making
• psychopathy

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Much of the literature regarding moral cognition in adults has been dominated by studies using sacrificial dilemmas (Kahane, 2015). Perhaps the most famous dilemma is the Trolley Problem (Thomson, 1985), which asks participants to decide if it is morally permissible to pull a lever in order to divert a trolley onto a secondary track, saving the lives of five strangers on the primary track, but leading to the death of one stranger. Ostensibly, pulling the lever is a utilitarian choice, while condemning such an action is indicative of deontological ethics. Greater neural response in dlPFC and ACC, or vmPFC, PCC, and TPJ, have been interpreted within a dual-process framework, where deontological rules arise from emotional responses, but utilitarian judgments depends on cognitive deliberation. This approach has been used to argue for specific emotional deficits in frontal lesion populations (Koenigs et al., 2007) and psychopathy (Koenigs, Kruepke, Zeier, & Newman, 2012). However, critics argue that the legal implications of this approach have been overstated (Pardo & Patterson, 2016). Sacrificial dilemmas have also been criticized because they rarely present a true utilitarian response option, may not require moral reasoning, and are unlikely to reflect how moral decision-making occurs for most people during their everyday lives (Kahane, Everett, Earp, Farias, & Savulescu, 2015).

2. According to the social domain theory, people across cultures and from an early age distinguish between norms whose violation results in unjust treatment or in harmful consequences to others from those whose violation challenges contextually relative and arbitrary social conventions or norms that structure social interactions (Nucci & Nucci, 1982; Turiel, 1983). Findings from a recent fMRI study suggest a common valence-based decision-making underpinning judgments of both harm/welfare-based and social-conventional social, but also indicate that judgments of different norms are marked by differences in the forms of affect associated with their transgression and relative recruitment of specific computational processes (White et al., 2017).

Additional information

Funding

This work was supported by the US Department of Defense MINERVA under FA9550-16-1-0074; and National Institute of Mental Health under R01MH109329 to Dr. Jean Decety.