Human Nature

, Volume 14, Issue 1, pp 53–72 | Cite as

Social network size in humans

  • R. A. HillEmail author
  • R. I. M. Dunbar


This paper examines social network size in contemporary Western society based on the exchange of Christmas cards. Maximum network size averaged 153.5 individuals, with a mean network size of 124.9 for those individuals explicitly contacted; these values are remarkably close to the group size of 150 predicted for humans on the basis of the size of their neocortex. Age, household type, and the relationship to the individual influence network structure, although the proportion of kin remained relatively constant at around 21%. Frequency of contact between network members was primarily determined by two classes of variable: passive factors (distance, work colleague, overseas) and active factors (emotional closeness, genetic relatedness). Controlling for the influence of passive factors on contact rates allowed the hierarchical structure of human social groups to be delimited. These findings suggest that there may be cognitive constraints on network size.

Key words

Frequency of contact Group size Humans Neocortex size Social networks 


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Copyright information

© Springer 2003

Authors and Affiliations

  1. 1.University of LiverpoolUK
  2. 2.Evolutionary Anthropology Research Group, Department of AnthropologyUniversity of DurhamDurhamU.K.

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