The social brain hypothesis and its implications for social evolution
The social brain hypothesis and its implications for social evolution
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DOI：
10.1080/03014460902960289
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发表时间：
2009-01-01
影响因子：
1.7
通讯作者：
Dunbar, R. I. M.
中科院分区：
文献类型：
--
作者：
Dunbar, R. I. M.
社会脑假说的提出是为了解释灵长类动物与其他脊椎动物相比，具有不同寻常的大大脑：灵长类动物进化出大大脑是为了管理它们不同寻常的复杂社会系统。尽管这一假说已被推广到所有脊椎动物类群，作为对大脑进化的解释，但最近的分析表明，社会大脑假说在其他哺乳动物和鸟类身上的形式与在类人猿灵长类动物身上的形式非常不同。在灵长类动物中，大脑大小与社会群体大小之间存在定量关系（群体大小是大脑大小的单调函数），这可能是因为社会性的认知需求限制了一个连贯群体中可以维持的个体数量。在其他哺乳动物和鸟类中，这种关系是定性的：大的大脑与交配系统的分类差异有关，拥有成对交配系统的物种拥有最大的大脑。似乎类人猿灵长类动物已经将一夫一妻制的结合过程推广到其他非生殖关系（“友谊”），从而产生了我们在这个分类单元中发现的群体大小和大脑大小之间的定量关系。这就提出了一个问题：为什么亲密关系对认知的要求如此之高（实际上，也提出了关于亲密关系到底是什么的问题），以及灵长类动物何时以及为什么会在社交方式上发生这种变化。
The social brain hypothesis was proposed as an explanation for the fact that primates have unusually large brains for body size compared to all other vertebrates: Primates evolved large brains to manage their unusually complex social systems. Although this proposal has been generalized to all vertebrate taxa as an explanation for brain evolution, recent analyses suggest that the social brain hypothesis takes a very different form in other mammals and birds than it does in anthropoid primates. In primates, there is a quantitative relationship between brain size and social group size (group size is a monotonic function of brain size), presumably because the cognitive demands of sociality place a constraint on the number of individuals that can be maintained in a coherent group. In other mammals and birds, the relationship is a qualitative one: Large brains are associated with categorical differences in mating system, with species that have pairbonded mating systems having the largest brains. It seems that anthropoid primates may have generalized the bonding processes that characterize monogamous pairbonds to other non-reproductive relationships ('friendships'), thereby giving rise to the quantitative relationship between group size and brain size that we find in this taxon. This raises issues about why bonded relationships are cognitively so demanding (and, indeed, raises questions about what a bonded relationship actually is), and when and why primates undertook this change in social style.