Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK.
Philos Trans R Soc Lond B Biol Sci. 2012 Aug 5;367(1599):2192-201. doi: 10.1098/rstb.2012.0121.
The social brain hypothesis (an explanation for the evolution of brain size in primates) predicts that humans typically cannot maintain more than 150 relationships at any one time. The constraint is partly cognitive (ultimately determined by some aspect of brain volume) and partly one of time. Friendships (but not necessarily kin relationships) are maintained by investing time in them, and failure to do so results in an inexorable deterioration in the quality of a relationship. The Internet, and in particular the rise of social networking sites (SNSs), raises the possibility that digital media might allow us to circumvent some or all of these constraints. This allows us to test the importance of these constraints in limiting human sociality. Although the recency of SNSs means that there have been relatively few studies, those that are available suggest that, in general, the ability to broadcast to many individuals at once, and the possibilities this provides in terms of continuously updating our understanding of network members' behaviour and thoughts, do not allow larger networks to be maintained. This may be because only relatively weak quality relationships can be maintained without face-to-face interaction.
社会脑假说（解释灵长类动物大脑大小进化的理论）预测，人类通常一次无法维持超过 150 种关系。这种限制部分是认知上的（最终由大脑体积的某个方面决定），部分是时间上的。通过投入时间来维持友谊（但不一定是亲属关系），否则会导致关系质量不可避免地恶化。互联网，尤其是社交网络（SNS）的兴起，提出了数字媒体可能使我们绕过这些限制的部分或全部的可能性。这使我们能够测试这些限制在限制人类社交性方面的重要性。尽管 SNS 出现的时间相对较短，但现有的研究表明，一般来说，一次向多个个体广播的能力，以及这在不断更新我们对网络成员行为和想法的理解方面提供的可能性，并不允许维持更大的网络。这可能是因为如果没有面对面的互动，只能维持相对较弱的关系。
