Monday, March 11, 2013

The Two Wilsons on Group Selection

In connection with the paper I have been writing, I have been thinking a lot about group selection.  I have incorporated this quote from E. O. Wilson’s The Social Conquest of the Earth:
An iron rule exists in genetic social evolution.  It is that selfish individuals beat altruistic individuals, while groups of altruists beat groups of selfish individuals.  The victory can never be complete; the balance of selection pressure cannot move to either extreme
This strikes me as a very powerful formulation.  It includes the fundamental problem presented by the evolution of morality.  Here is how David Sloan Wilson and Edward O. Wilson put it in RETHINKING THE THEORETICAL FOUNDATION OF SOCIOBIOLOGY (Quarterly Review of Biology, December 2007).  
During evolution by natural selection, a heritable trait that increases the fitness of others in a group (or the group at a whole) at the expense of the individual possessing the trait will decline in frequency within the group. This is the fundamental problem that Darwin identified for traits associated with human morality, and it applies with equal force to group-advantageous traits in other species. It is simply a fact of social life that individuals must do things for each other to function successfully as a group, and that these actions usually do not maximize their relative fitness within the group.
The question here is how to explain the emergence of genuinely altruistic behaviors in human beings and other animals.  What separates the Mensheviks from the Bolsheviks in contemporary evolutionary theory is that the former try to explain it away whereas the latter try to explain how it can be what it seems to be. 
Explaining it away means interpreting apparently altruistic behavior as selfish behavior, keeping the rule that any behavior selected for must advance the genetic interests of the individual within the group.  If I share my kill with the rest of the tribe, that is because big hunters get lots of pussy. 
Explaining altruistic behavior while accepting that it is, genuinely, altruistic, may require group selection.  Cooperation is a trait not of individuals but of partnerships.  If you and I make sacrifices for each other, our business model turns a profit.  Groups with a lot of altruists out compete those with few, resulting in an increase of altruists in the larger population. 
I suppose that both approaches have value, but that puts me squarely on the side of the Bolsheviks.  The Mensheviks will allow only the selfish interpretation. 
The other thing that is presented in the E. O. Wilson quote is that group selection best makes sense of the moral dimension in human beings.  If group selection works, it will work against directly selfish behavior and the resulting schema will produce a being at odds with himself.  That would be me and you and all of us human beings. 
I also note that E. O. Wilson’s quote contains the paradox that we find in the prisoner’s dilemma.  In that diabolical issue of game theory, it makes perfect sense for each of us to defect in our partnership; nonetheless, we would both be better off if we cooperated.  I think that the Wilson’s are on to something. 

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