来自Claremont Graduate Universtiy的Paul J.Zak教授在11月7日的《公共科学图书馆·综合》（PLoS ONE）上发表了一篇题为“催产素让人慷慨”（Oxytocin Increases Generosity in Humans）的研究论文。该研究是在他们两年前发表在《自然》杂志上的有关催产素和信任的新发现的延伸。
在这项研究中，Zak和他的同事让参与试验者服用一定剂量的催产素和一种安慰剂，然后测试他们如何与陌生者分钱。结果基本上是一边倒：那些接受了催产素的人给出的钱比那些接收安慰剂的人多出80%。
Zak指出，这意味着尽管我们天生是利他、无私心的，我们还会在感觉对另外一个人产生移情作用时很大方。就是这种“移情作用”使得我们打开钱包去大方地帮助陌生人。这项试验的结果证实了该研究组之前的研究发现：催产素影响信任，但是对慷慨程度的影响更加大。
催产素尤其能够影响人用钱时的慷慨程度。在之前的研究中，Zak证实了催产素和信任之间的关联，从而弄清了古老的荷尔蒙导致大脑中化学变化的一个迁移——这在进化上很重要。因为我们越容易相信别人并合作，我们就越能够一起获益。
垂体后叶组织中所提纯的一种激素。由下丘脑的室旁核合成，系神经内分泌。合成后沿室旁核—垂体束的轴浆流动而至垂体后叶，贮存于后叶的神经末梢颗粒中，为8个氨基酸组成的多肽。
催产素具有刺激乳腺及子宫的双重作用：对乳腺有促进乳腺射乳的作用，作用于乳腺内平滑肌，使其收缩产生压力，从而使乳汁排出腺泡进入导管和乳窦。吸吮时所产生的负压克服乳头括约肌阻力，使乳汁流出。对非孕子宫作用小，对妊娠子宫，在妊娠末期对其敏感。雌激素可增加子宫对催产素的敏感性，而孕激素作用则相反。由于催产素可使子宫强烈收缩，可减少产后流血。临床上常用于产后止血。刺激催产素分泌的有效刺激为吸吮乳头和扩张子宫颈，为反射活动，神经冲动由外周神经传入中枢神经系统，兴奋下丘脑室旁核，引起催产素释放。
此前，以色列科学家的一项最新研究发现，一种大脑垂体分泌催产素(Oxytocin)影响着人类中母子紧密关系的程度。
原始出处:
PLoS ONE
Oxytocin Increases Generosity in Humans
Paul J. Zak1,2*, Angela A. Stanton3, Sheila Ahmadi4
1 Center for Neuroeconomics Studies and Department of Economics, Claremont Graduate University, Claremont, California, United States of America, 2 Department of Neurology, Loma Linda University Medical Center, Loma Linda, California, United States of America, 3 Argyros School of Business & Economics, Chapman University, Orange, California, United States of America, 4 Division of Endocrinology, Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
Abstract
Human beings routinely help strangers at costs to themselves. Sometimes the help offered is generous—offering more than the other expects. The proximate mechanisms supporting generosity are not well-understood, but several lines of research suggest a role for empathy. In this study, participants were infused with 40 IU oxytocin (OT) or placebo and engaged in a blinded, one-shot decision on how to split a sum of money with a stranger that could be rejected. Those on OT were 80% more generous than those given a placebo. OT had no effect on a unilateral monetary transfer task dissociating generosity from altruism. OT and altruism together predicted almost half the interpersonal variation in generosity. Notably, OT had twofold larger impact on generosity compared to altruism. This indicates that generosity is associated with both altruism as well as an emotional identification with another person.
Received: June 16, 2007; Accepted: October 13, 2007; Published: November 7, 2007
英文全文链接：
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0001128
