The Vrije Universiteit Amsterdam is hosting the annual conference of the European Human Behaviour and Evolution Association (EHBEA) until Wednesday. I am attending and will try to cover as much of the conference as possible on this blog.
Before the official kick-off of the conference on Monday, Joe Henrich of the University of British Columbia in Vancouver presented a first keynote tonight. Henrich is trained as an anthropologist (and aviation engineer!), but has collaborated widely with economists like Ernst Fehr and Colin F. Camerer and psychologists like Mark van Vugt, who convened the session. Henrich has prominently pointed out the fallacy of basing behavioural research purely on ‘WEIRD’ (Western, educated, industrialised, rich, democratic) people, and advocated a cross-cultural approach.1
In his talk on the ‘Culture-Gene Coevolutionary Origins of Human Cooperation’, Henrich aimed to root out remnants of the idea that ecological and cultural explanations are conflicting. Rather, as he said, “cultural evolution provides a set of psychologically and evolutiarly grounded processes that can plausibly create patterns of ecological adaptation”.
This view as profound implications for the foundations of evolutionary psychology. There is, for example, the attempt to establish conditions in the ‘Environment of Evolutionary Adaptiveness’ (EEA). However, culture-gene coevolution implies that recurrent features of selective environments are themselves the product of cultural evolution.
With regards to the evolution of human cooperation, Henrich presented five “challenges for a theory of large-scale human cooperation”:
1) Why is the scale and intensity of human cooperation so much greater than other mammals – at least in some societies?
2) Why does the scale and intensity of cooperation and collective action vary so dramatically across a) societies and b) domains?
3) Why has the scale and intensity of human cooperationa nd collective action expanded so dramatically in the last 10,000 years?
4) Why do the mechanisms that sustain cooperation also sustain non-cooperative behaviour (food taboos, sexual practices, rituals), including maladaptive stuff?
5) Why do the ‘sustaining mechanisms’ vary across societies?
Over the last decade or two, a variety of cultural evolutionary models have been proposed that can sustain varying degrees of large-scale cooperation. Henrich singled out three of these families of models in particular:
1) Diffuse costly punishment (which can sustain norms).2
2) Positive indirect reciprocity linkage (which can sustain norms).3
3) Signaling (which can stabilize costly punishment, and maybe by that way also norms).
Because all of these models have multiple stable equilibria, they are unlikely to explain genetic evolution. Rather, “these are some of the tricks that cultural evolution can use to exploit our evolved psychology”. However, Henrich’s own field work (among horticulturist-fishers on a Fijian island) indicates that de facto, none of these models explain norm enforcement in existing societies.
Henrich and his colleagues observed that on Yasawa Island, “negative indirect reciprocity stabilizes social norms”. The existing “reputation system harnesses simmering jealousies, past grievances, status rivalries, and desire to steal to sustain costly norms, including cooperation.” When a villager breaks a norm (either cooperative or not), this creates an opportunity for others to act against the violator, e.g. by means of theft, damaging property, or physical violence. These incidents are either not investigated, or at least associated with much less reputational damage than when committed against norm-abiding neighbours.
From a methodological perspective, the lesson is that “evolution is smarter than us”: Evolutionary models should be based on observations in the field. Or, as Henrich puts it, we “we need to go out in the world and ask the right questions”. A second point is that the focus on the evolution of cooperation could be misguided. Rather, we need to understand social norms, cooperative or not, and mechanisms by which they are enforced.
- Henrich, J., Heine, S. J., & Norenzayan, A. (2010). The weirdest people in the world?. The Behavioral and Brain Sciences, 33(2-3), 61-135. DOI: 10.1017/S0140525X0999152X [↩]
- Boyd, R. & Richerson, P. J. (1992). Punishment Allows the Evolution of Cooperation (or Anything Else) in Sizable Groups. Ethology and Sociobiology, 13, 171-95. DOI: 10.1016/0162-3095(92)90032-Y [↩]
- Nowak, M. A. & Sigmund, K. (2005). Evolution of indirect reciprocity. Nature, 437(7063), 1291-8. DOI: 10.1038/nature04131 [↩]