The evolution of cooperation: from networks to institutions

Our ancestral environment differed greatly from our current environment, for the better (we enjoy better, safer and longer lives than our ancestors) but also for the worse. In his text, Dunbar points out, in particular, that while we used to spend our whole life with the same people, we now live mostly with strangers, people we have not known for long and with whom we will probably not interact in the future. This, Dunbar argues, may threaten the very foundation of our social life: “in the kinds of weakly interconnected communities in which we now live, people are no longer so willing to intervene either in minor infringements of social mores or in the abuse and mistreatment of others. We are no longer prepared to protect the wider interests of the community.”

It might be, however, that things are not that much worse, for two reasons linked to the evolution of human cooperation. Let’s first consider the biological aspect of human cooperation. In his text, Dunbar assumes that social cooperation is sustained by third-party intervention (in line with group selection, see for instance Boyd et al. 2005). However, empirical studies demonstrate that actually, third-party intervention plays a minor role in the prevention of cheating. Among hunter-gatherers, punishment is rare if not absent (Marlowe 2010, Wiessner 2005, for a review, see Baumard 2010 and Guala 2012). Instead, what leads individuals to cooperate is the prospect of losing their partners. As Dunbar points out, humans’ ancestral groups were highly fluid, and individuals were constantly moving from one group to another, seeking better and more reliable partners. In this situation, what prevented individuals from cheating others was the prospect of losing their reputation as reliable partners and deterring future partners from cooperating with them (Baumard et al. in press).

If this view is correct, then it might be the case that our modern environment is more (and not less) favorable to cooperation than the ancestral environment. Indeed, we may move from one university to the other, from one job to the next, but our administrative identity, our Facebook page, our credit rating always follow us. Today, information circulates much better than before and the whole planet is now totally connected. It is thus harder to escape from a bad reputation and as a result the costs of a bad reputation are higher than before.

Now consider the cultural dimension of human cooperation. Dunbar is right that networks have their limits in regulating individuals’ behavior. As we move from hunter-gatherer groups to bigger and bigger societies, reputation becomes less and less useful in cooperation involving thousands of people who often do not have the time and resources to inquire into their partners’ reputations. However, since the Neolithic revolution, humans have developed a new way to sustain cooperation: namely, institutions. Economists define institutions as second-order collective actions: that is, collective actions that regulate first-order collective actions such as collective fishing, collective defense, collective insurance, etc. (North 1990). In his article, Dunbar evokes the army (that is, the state) as an example of such second-order collective actions, but empirical studies show that people spontaneously set up associations and organizations, appoint watchmen and arbitrators, define rules and fines for breaking these rules, and do so without any kind of state support (Ostrom, 1990).

Institutions allow humans to regulate herding in a common pasture, fishing in a common fishery, water consumption in an irrigation system, etc. More generally, history suggests that institutions have been very successful, decreasing the level of violence, creating large markets, redistributing resources from the rich to the poor, etc. Thus, while as Dunbar points out, we are more and more surrounded with strangers, our society has also appointed more and more strangers to help us. We now have policemen, firemen, judges, teachers, journalists, epidemiologists, therapists, etc.. In fact, the welfare state now accounts from a third to half of GDP in most developed countries.

To conclude, while there are indeed some reasons to worry – trust is in decline (Putnam 2001) and well-being is not progressing as much as it used to do (Wilkinson and Pickett 2009) – this might not be because networks are becoming looser, but rather because the foundations of our institutions are not as strong as they were. Many studies, for instance, suggest that equality is an important factor in the creation of open, fair and efficient institutions (Alesina and Glaeser, 2004; Fukuyama, 2011). If this is true, then the rise of inequalities might be an central problem in the years to come.

Nicolas Baumard
University of Pennsylvania


Alesina, A. & Glaeser, E. (2004) Fighting poverty in the US and Europe: A world of difference. Oxford University Press.

Baumard, N., André, J.B. and Sperber, D., (in press) A mutualistic approach to morality, Behavioral and Brain Sciences.

Baumard, N. (2010) Has punishment played a role in the evolution of cooperation? A critical review. Mind & Society 9(2):171–92.

Boyd, R., Gintis, H., Bowles, S. & Richerson, P. (2003) The evolution of altruistic punishment. Proceedings of the National Academy of Sciences USA 100(6):3531–35.

Fukuyama, F. (2011) The Origins of Political Order:  From Prehuman Times to the French Revolution, New York:  Farrar, Straus and Giroux.

Guala, F. (in press) Reciprocity: Weak or strong? What punishment experiments do (and do not) demonstrate. Behavioral and Brain Sciences.

Marlowe, F. (2009) Hadza cooperation: Second-party punishment, yes; third-party punishment, no. Human Nature 20(4):417–30.

North, D. (1990) Institutions, Institutional Change and Economic Performance, Cambridge University Press.

Ostrom, E. (1990) Governing the commons: The evolution of institutions for collective action. Political economy of institutions and decisions. Cambridge University Press.

Putman, R.D. (2001). Bowling Alone: The Collapse and Revival of American Community. New York: Simon & Schuster.

Wiessner, P. (2005) Norm enforcement among the Ju/’hoansi Bushmen: A case of strong reciprocity? Human Nature 16(2):115–45.

Wilkinson, R. & Pickett, K. (2009). The Spirit Level: Why More Equal Societies Almost Always Do Better. Harmondsworth: Allen Lane.

Published On: May 8, 2012

Nicolas Baumard

Nicolas Baumard

I am the holder of the Chaire d’Excellence Recherche “The Evolution of Fairness” funded by PSL* and the co-leader of the Evolution and Social Cognition Group at the Department of Cognitive Science of the Ecole Normale Supérieure.
I am interested in using evolutionary and psychological approaches in social sciences, including economics, philosophy, anthropology and history.


  • Peter Turchin says:

    Nicolas, you argue that among hunter-gatherers, punishment is rare if not absent. However, later you say that individuals want to maintain good reputation so that future partners will participate in cooperative ventures with them. Yet, withdrawing cooperation is a form of punishment. Furthermore, Christopher Boehm has gathered a lot of data suggesting that hunter-gatherers use a graduated system of punishment against ‘upstarts’ (which is another form of non-cooperative behavior). These sanctions beging with mild ones, like gossip and ridicule, and then graduate to severe ones, like ostracism and assassination/capital punishment. So this would argue that punishment among hunter-gatherers is actually not absent. It may be rare, because most ‘deviants’ will get the idea from gossip and ridicule and desist, but it is not absent. Many theorists, e.g. Herb Gintis, argue that punishment is a critical, and perhaps even necessary mechanism in sustaining cooperation. Comments?

  • Hi Peter,

    Thanks for your comment! Several points:

    1. “you argue that among hunter-gatherers, punishment is rare if not absent( …) yet, withdrawing cooperation is a form of punishment.”
    > Withdrawing cooperation clearly imposes a cost on the wrongdoer. Yet, it is not altruistic punishment because its function is not to impose a cost (and sustain cooperation within the group) but to provide a benefit to the individual who withdraw cooperation. Indeed, interacting with a cheater is very costly and it is better to choose better partners when these alternative partners are available (which usually the case in highly fluid societies of hunter-gatherers).

    2. “Christopher Boehm has gathered a lot of data suggesting that hunter-gatherers use a graduated system of punishment” (…) “like gossip and ridicule, and then graduate to severe ones, like ostracism and assassination/capital punishment.”
    > Right, but again, gossip, ridicule and ostracism can very well be self-serving behaviors. As for assassination, Boehm’s own data clearly show that they are very rare and concern highly dangerous individuals whose behavior is almost pathological and who are a danger for the whole group, and are treated as such. In any case, these very clear cases of costly interventions do not occur in daily life and do not serve to sustain the kind of cooperative behavior group selectionists want to explain.,

    3. “Many theorists, e.g. Herb Gintis, argue that punishment is a critical, and perhaps even necessary mechanism in sustaining cooperation.”
    > The problem with such a view is that it is not backed by empirical data. Anthropologists working on pre-state societies never report cases of altruistic punishment. What is funny is that the empirical papers (such as Wiessner’s) used by Gintis to back his theory actually show the contrary, that, when people are confronted with cheaters, they rather walk away and choose better partners! It is true that people punish in artificial economic games (when given the instruction and the money to punish though). But what does this show if people do not punish in the field!?

    For a very good discussion of this point, see Guala’s recent paper in BBS “Reciprocity: Weak or strong? What punishment experiments do (and do not) demonstrate”:

  • Juan Alfonso del Busto says:

    I think this is a very very good commmentary on Dunbar, though I also think that social punishment should be taken into account as real punishment, even though it is not costly for the “social punishers”, because it can be dramatically costly for the socially punished. Reputation in a group can be of high survival and reproductive relevance, and I bet that reputation can even travel among hunter-gatherer groups through gossip when these groups hold their annual meetings. Anyway It seems to me that you are both deffending the same point.

    You don´t have to go to the scientific literature on hunter-gatherers to see the reality and reach of social punishment. Our daily social experience can tell us. Shame, social failure and frustration can literally break us down and turn our immune system into a useless junk.

    We humans have developed a plethora of emotions (shame, ridicoulousness, vengeance, guilt, pride, etc) that coadyuvate this social punishment or whatever yoy want to call it. These emotions are probably there to amplify the consequences of this mild social punishment. Those of us who are more sensitive to these emotions are more likely to behave. Those of us who are insensitive to these emotions are more likely to become free-riders.

    All these emotions and instincts should be considered adaptations and must have evolved for a reason. In my opinion they could have evolved through a complex multilevel selection dynamics in which group selection played a major role, since the group level is the level which obtains more of a profit from them.

    We also know first-hand that we are willing to swear vengeance on someone who has done something very unfair to us, and that we are willing to take our vengeance even if it is costly for us. Of course this is exceptional, and most of the times we simply walk away, but the feelings are there, waiting for the right moment: we also have an episodic memory for a reason.

  • tmtyler says:

    Re: “Among hunter-gatherers, punishment is rare if not absent”

    Er, no it isn’t. Your supplied references don’t support this claim. Indeed the second one flatly contradicts it, saying:

    “three social institutions central to the achievement of cooperation that have a strong impact on incentive, norms, rewards, and punishment are found in most mobile forager societies:”

  • Please, read beyond the second page of the article!

    Just two quotes:

    ‘‘minimal energy was wasted on incorrigible free-riders; unless they were
    disruptive to community, they were accepted for whatever they and their
    families did contribute.’’ (p. 135)

    ‘‘In view of arguments that punishment by coalitions is largely a means to curb
    free-riders (Price et al. 2002), it is surprising what a small percent of
    punishment (14% of all cases) was aimed at able-bodied free-riders who
    regularly failed to produce enough to share widely with the community or
    tried to consume more than their share on a daily basis. Only 5 of 32 cases
    involved criticism for low work effort even though there were capable
    individuals in all camps who produced far less than others. People did not
    bother with those who were regularly lazy, stingy, or greedy. Rather, the
    penalty for low production or stinginess was not verbal punishment but low
    social regard, fewer marriage opportunities, or fewer exchange partnerships
    (Wiessner 2002b).’’ (p. 124)

    Here is a reader:

    Good read!

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