Serotonin selectively influences moral judgment and behavior through effects on harm aversion
Serotonin selectively influences moral judgment and behavior through effects on harm aversion
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DOI：
10.1073/pnas.1009396107
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发表时间：
2010-10-05
影响因子：
11.1
通讯作者：
Robbins, Trevor W.
中科院分区：
文献类型：
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作者：
Crockett, Molly J.;Clark, Luke;Robbins, Trevor W.
对真实或想象的社会伤害的厌恶情绪反应会注入道德判断并激发亲社会行为。在这里，我们证明神经递质血清素通过增加受试者对人身伤害他人的厌恶来直接改变道德判断和行为。我们使用西酞普兰（一种选择性血清素再摄取抑制剂）增强健康志愿者的血清素，并将其与药物对照治疗和安慰剂在道德判断和行为测试中的效果进行对比。我们在一系列道德“困境”中衡量了药物对道德判断的影响，将功利主义结果（例如，拯救五个生命）与高度厌恶的有害行为（例如，杀死无辜者）进行比较。血清素的增加使受试者更有可能判断有害行为是被禁止的，但仅限于在情感上造成明显伤害的情况下。西酞普兰后的这种避免伤害的偏见在最后通牒游戏中的行为中也很明显，在最后通牒游戏中，受试者决定接受或拒绝来自另一位玩家的公平或不公平的金钱提议。拒绝不公平的提议可以强制执行公平规范，但也会在经济上损害其他玩家。增强血清素可以降低受试者拒绝不公平提议的可能性。此外，西酞普兰的亲社会效应随着特质同理心的变化而变化。与特质同理心低的个体相比，特质同理心高的个体显示西酞普兰对道德判断和行为的影响更强。总之，这些发现提供了独特的证据，证明血清素可以通过增强伤害厌恶感来促进亲社会行为，伤害厌恶感是一种直接影响道德判断和道德行为的亲社会情绪。
Aversive emotional reactions to real or imagined social harms infuse moral judgment and motivate prosocial behavior. Here, we show that the neurotransmitter serotonin directly alters both moral judgment and behavior through increasing subjects' aversion to personally harming others. We enhanced serotonin in healthy volunteers with citalopram (a selective serotonin reuptake inhibitor) and contrasted its effects with both a pharmacological control treatment and a placebo on tests of moral judgment and behavior. We measured the drugs' effects on moral judgment in a set of moral 'dilemmas' pitting utilitarian outcomes (e.g., saving five lives) against highly aversive harmful actions (e.g., killing an innocent person). Enhancing serotonin made subjects more likely to judge harmful actions as forbidden, but only in cases where harms were emotionally salient. This harm-avoidant bias after citalopram was also evident in behavior during the ultimatum game, in which subjects decide to accept or reject fair or unfair monetary offers from another player. Rejecting unfair offers enforces a fairness norm but also harms the other player financially. Enhancing serotonin made subjects less likely to reject unfair offers. Furthermore, the prosocial effects of citalopram varied as a function of trait empathy. Individuals high in trait empathy showed stronger effects of citalopram on moral judgment and behavior than individuals low in trait empathy. Together, these findings provide unique evidence that serotonin could promote prosocial behavior by enhancing harm aversion, a prosocial sentiment that directly affects both moral judgment and moral behavior.