The last book in this review is co-authored by Clive Gamble, John Gowlett and Robin Dunbar.  Here the authors make a well substantiated claim that our mind was shaped by the social pressures of evolution.  Dunbar is best known by association to his earlier work on the “Dunbar number”, the hypothesised optimal (and maximal) size for a homo sapiens social group.  The magic number is 150 and is linked with the size of the neocortex (the top part of the brain) in social mammals.  This is confirmed in many articles of network science.  The evolutionary need of homo sapiens to facilitate larger group sizes is (according to these authors) behind the development of language which is seen as an efficient substitute to grooming.  I have kept extensive notes on this book which is the most directly academic of the three and I reflect on some of the claims below.

The authors start from the Machiavellian intelligence hypothesis (we need large brains to be able to deceive others in our social group) to which Gamble et al counter with the social brain hypothesis.  They claim that sophisticated social animals need to be able to mentalize (infer others state of mind) at high levels of sophistication and to understand complex social structure while maintaining cohesion.  Laughter and music act as substitutes to grooming and are termed social grooming.  Social grooming happens in our mind.  And our mind is about being relational and not just rational.  All social emotions (guilt, shame, pride) are only possible when a belief exists about another’s belief (mentalizing).  By developing social structures and language we are also able to “store relationships”, which facilitates the creation of even larger social units. While language is furthermore driven by the necessity to accommodate interaction with “unobserved” others.

A number of other concepts are weaved into the argument: The tools (and by implication technology) we invent are inherently social artefacts. Religion is only possible as a result of social continuity (by implication we espouse the religion of the dominant groups).  The increase in group size (that was brought about by competition and facilitated by our enlarged neocortex) is responsible for the evolution of religion, leadership and warfare.

My own observation is that if a social brain confers relative advantage to a species we need to reflect more on the creation of social knowledge. There is an individual level social brain and a societal brain, as the collective knowledge and processing ability of multiple individuals.  There is a wiring issue at hand: cognitive processing is not just dependent on the processing capacity of units (at the individual or even collective level) but substantively by the way information is processed within the group.  To that end societal institutions provide the parameters (constraints) to such wiring.  Potentially mapping these through social network analysis is a meaningful way of considering the creation and maintenance of social knowledge.

Another reflection is on the implication of these theories for political institutions.  If charismatic leadership is an evolutionary answer to the coherence of large groups then pure democracy might be inherently impossible.  A democratic polis will be inevitably constrained to small groups due to human cognitive limitations. It will also be constrained by collective action problems.  Methodologically (or epistemologically to be more precise) understanding collective intelligence requires providing an answer to utility maximising problems that can be conceptualised as network complexity problems.