Dunbar's number

Robin Dunbar suggested that there exists a cognitive limit for a size of close friends and the number of human is about 150. Specifically, he claimed that the volume of orbital prefrontal cortex predicts the social network size across primates1.

From Twitter2 and mobile phone communication data3. MacCarron2016calling.

References


  1. Powell, J.; Lewis, P. A.; Roberts, N.; Garcia-Finana, M.; Dunbar, R. I. M. (2012). “Orbital prefrontal cortex volume predicts social network size: an imaging study of individual differences in humans”. Proceedings of the Royal Society B: Biological Sciences 279 (1736): 2157–2162. doi:10.1098/rspb.2011.2574. ISSN 0962-8452 

  2. Perc, Matjaz; Gonçalves, Bruno; Perra, Nicola; Vespignani, Alessandro (2011). “Modeling Users’ Activity on Twitter Networks: Validation of Dunbar’s Number”. PLoS ONE 6 (8): e22656. doi:10.1371/journal.pone.0022656. ISSN 1932-6203 

  3. “Time as a limited resource: Communication Strategy in Mobile Phone Networks”. http://arxiv.org/abs/1301.2464.