"There is a cognitive limit to the number of individuals with whom anyone can maintain relationships" #readingToday  

The essence of my argument has been that there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size. The predicted group size for humans is relatively large (compared to those for nonhuman primates), and is close to observed sizes of certain rather distinctive types of groups found in contemporary and historical human societies. These groups are invariably ones that depend on extensive personal knowledge based on face-to-face interaction for their stability and coherence through time. I argued that the need to increase group size at some point during the course of human evolution precipitated the evolution of language because a more efficient process was required for servicing these relationships than was possible with the conventional nonhuman primate bonding mechanism (namely, social grooming). These arguments appear to mesh well with the social intelligence hypothesis for the evolution of brain size and cognitive skills in primates.