The neurobiology of social decision-making
Introduction
Decisions made in social contexts can be almost reflexive (should I be a good Samaritan?) or vexingly complicated (how do I best negotiate a job offer?). Yet despite their variety and difficulty, social decisions have much in common with the typical reward harvesting problems that have been the traditional focus of laboratory investigation. In both social and non-social dilemmas, problems can be represented as a set of states and actions in which agents make transitions in order to move toward states with greater associated reward, whether it be in the currency of a food pellet or a job promotion.
However, social decisions do differ in one important way: Such decision-problems can be non-stationary in a very specific sense: the value associated with one agent's action depends critically on the changing actions (and mental states) of other social agents. Thus, a job candidate should make careful estimates about the likely actions of a potential employer (likely actions given a set of one's own actions), when considering their next move. In such social dilemmas, strategic decisions must be tailored and updated to the particular mental state of another.
Recent productive collaborations between neuroscientists, psychologists and economists have led to a concerted effort to investigate the neural correlates of social decision-making [1]. By combining a variety of neuroscientific methods with simple, but sophisticated tasks derived from a branch of experimental economics known as game theory, this research endeavor has already uncovered some compelling findings with regard to the neural bases of social decision-making.
Section snippets
Reciprocal exchange
One specific focus of game theory is to model reciprocal exchange, in which an individual provides something of value to a social partner with the expectation that the recipient will reciprocate in the future. Although greed and fear of exploitation threaten the stability of reciprocal exchange, society as a whole is more productive when reciprocity is thriving [2]. Typically, reciprocal exchange is studied via the Trust, and closely related Prisoner's Dilemma, games. In the Trust Game (TG), a
Bargaining
Bargaining games are another common focus of game theory, with the family of Dictator and Ultimatum games often used to examine responses to equality and inequality. In the Dictator Game (DG), one player (the Proposer) decides how much of an endowment to award to the second player (the Responder). Allocations in this game measure pure altruism, in that the Proposer (usually) sacrifices some personal gain to share the endowment with their partner. The Ultimatum Game (UG) is a variant which
Psychopathology
While the methodological and theoretical approaches of decision neuroscience have begun to uncover the neural computations underlying multiagent interactions and complex social phenomena [46•], they also provide an opportunity to identify aberrant neural substrates underlying social pathologies. Much recent interest in developmental and adult psychiatry has focused on social features of mental illnesses ranging from autism and schizophrenia to borderline and antisocial personality disorders.
Conclusion
Many of our most important decisions are made in the context of social interactions. Recently, cognitive neuroscientists have begun to investigate the neural correlates of social decisions using tasks derived from a branch of experimental economics known as game theory. The caudate nucleus, and likely the mesolimbic dopamine system that projects to it, registers social prediction errors that guide decisions about reciprocity. Visceral feedback in response to negative social interactions,
References and recommended reading
Papers of particular interest, published within the period of review, have been highlighted as:
• of special interest
•• of outstanding interest
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