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on Neuroeconomics |
| By: | Emonds G.; Declerck C.H.; Boone Ch.; Vandervliet E.J.M.; Parizel P.M. |
| Abstract: | We use fMRI to investigate the neurological correlates of two factors that are known to enhance cooperative strategies in social dilemmas: the provision of extrinsic cooperative incentives, and the intrinsic motivation to cooperate. The former is achieved by changing the pay-off matrix of a mixed motive game (e.g., a Prisoner’s Dilemma, PD) to a coordination game (CG). The latter is achieved by comparing people who differ along the personality trait Social Value Orientation. Previous studies have indicated that proself oriented individuals (“hawks”) adopt a competitive strategy in a PD but switch to a cooperative strategy in a CG, while prosocial individuals (“doves”) maintain high levels of cooperation across games. A major aim of this study is to examine if there are fundamental neurological differences between prosocials and proselfs that substantiate these different behavioral strategies. Our imaging data of a full brain analysis contrasting PD and CG confirm that the PD poses a conflict (increased ACC activation) and induces subjects to think about the possible consequences for self and others (more prefrontal cortex activity). More importantly, a region of interest analysis contrasting prosocials and proselfs suggests that proselfs’ strategies are driven by calculation and self-interest. Increased activation was found in the precuneus, DLPFC, the posterior STS, and caudate nucleus. Prosocials’ strategies reflect norm compliance, morality, and social interaction. Increased activation was found in the lateral orbotifrontal cortex and the social brain network (including the ventromedial cortex, anterior STS, inferior parietal lobule, and amygdala). |
| Date: | 2008–09 |
| URL: | http://d.repec.org/n?u=RePEc:ant:wpaper:2008016&r=neu |
| By: | Declerck C.H.; Boone Ch.; Kiyonari T. |
| Abstract: | The neuropeptide Oxytocin (OT), implicated in mammalian social behavior, may affect cooperation through its anxiolytic and affiliative properties. The current study experimentally investigates how OT interacts with three well-studied determinants of cooperative behavior in social dilemmas: extrinsic incentives, social cues, and individual differences. Participants received OT or a placebo following a double blind procedure and played two economic games with randomly determined partners: a Coordination Game (with strong extrinsic incentives to cooperate (CG)) and a Prisoner’s Dilemma (with weak extrinsic incentives (PD)). Social cues were present when participants had the chance to meet their partners in advance, and absent when the interactions were anonymous. A first prediction, that OT enhances cooperation when social cues are present, was confirmed by the data. This appeared to be more pronounced when participants played a CG. In contrast, in a PD we predicted that OT’s influence on cooperation would depend on the subject’s intrinsic willingness to cooperate, as assessed by means of his/her Social Value Orientation and Machiavellianism. The data indicate that for prosocials, OT and social cues appear to be substitutes, with either one being sufficient to overcome fear of betrayal and elicit cooperation. For proselfs, OT and social cues appear to be complements: their concurrence is essential to overcome greediness in situations with weak cooperative incentives. Machiavellists cooperated very little overall, and the combination of OT and social cues, in contrast to proselfs, actually reduced machiavellists’ willingness to cooperate. |
| Date: | 2008–09 |
| URL: | http://d.repec.org/n?u=RePEc:ant:wpaper:2008014&r=neu |