School of Psychology, University of St Andrews, , St Andrews, UK, Department of Primatology, Max Planck Institute for Evolutionary Anthropology, , Leipzig, Germany, Budongo Conservation Field Station (BCFS), , Masindi, Uganda, Department of Anthropology, Boston University, , Boston, MA, USA, Wisconsin National Primate Research Center, , Madison, WI, USA, Cognitive Science Centre, University of Neuchâtel, , Neuchâtel, Switzerland.
Proc Biol Sci. 2014 Jan 15;281(1778):20133096. doi: 10.1098/rspb.2013.3096. Print 2014 Mar 7.
Humans excel in cooperative exchanges between unrelated individuals. Although this trait is fundamental to the success of our species, its evolution and mechanisms are poorly understood. Other social mammals also build long-term cooperative relationships between non-kin, and recent evidence shows that oxytocin, a hormone involved in parent-offspring bonding, is likely to facilitate non-kin as well as kin bonds. In a population of wild chimpanzees, we measured urinary oxytocin levels following a rare cooperative event--food sharing. Subjects showed higher urinary oxytocin levels after single food-sharing events compared with other types of social feeding, irrespective of previous social bond levels. Also, urinary oxytocin levels following food sharing were higher than following grooming, another cooperative behaviour. Therefore, food sharing in chimpanzees may play a key role in social bonding under the influence of oxytocin. We propose that food-sharing events co-opt neurobiological mechanisms evolved to support mother-infant bonding during lactation bouts, and may act as facilitators of bonding and cooperation between unrelated individuals via the oxytocinergic system across social mammals.
人类在与无亲属关系的个体之间进行合作交流方面表现出色。尽管这种特征是我们物种成功的基础，但它的进化和机制仍未得到很好的理解。其他社交性哺乳动物也在非亲属之间建立长期的合作关系，最近的证据表明，与母婴关系有关的激素催产素可能有助于建立非亲属以及亲属关系。在一个野生黑猩猩群体中，我们在一次罕见的合作事件——食物分享后测量了尿液中的催产素水平。与其他类型的社交进食相比，个体在单次食物分享事件后表现出更高的尿液催产素水平，而与之前的社交关系水平无关。此外，食物分享后的尿液催产素水平高于梳理行为后的水平，梳理也是一种合作行为。因此，在黑猩猩中，食物分享可能在催产素的影响下在社会联系中发挥关键作用。我们提出，食物分享事件利用了在哺乳期支持母婴关系的神经生物学机制，并且可能通过催产素系统在社交性哺乳动物中充当促进纽带和合作的媒介，促进无亲属关系的个体之间的联系和合作。
