Natural Rationality | decision-making in the economy of nature


Strong reciprocity, altruism and egoism

Proponents of the Strong Reciprocity Hypothesis (i.e., Bowles, Gintis, Boyd, Fehr, Heinrich, etc., I will call them “The Collective”) claim that human being are strong reciprocators: they are willing to sacrifice resources in order to reward fair and punish unfair behavior even if there is no direct or future reward. Thus we are, according to the Collective, innately endowed with pro-social preferences and aversion to inequity. Those who advocate strong reciprocity take it to be a a ‘genuine’ altruistic force, not explained by other motives. Strong reciprocity is here contrasted with weaker form of reciprocity, such as: cooperating with someone because of genetic relatedness (kinship), because one follows a tit-for-tat pattern (direct reciprocity), wants to establish a good reputation (indirect reciprocity) or displays signs of power or wealth (coslty signaling). Thus our species is made, ceteris paribus, of altruistic individuals that tend to cooperate with cooperators and punish defectors, even at a cost. Behavioral economics showed how people are willing to cooperate in games such as the prisoner’s dilemma, the ultimatum game or the trust game: they do not cheat in the first one, offer fair split in the second and transfer money in the third.

Could it be possible, however, that this so-called altruism is instrumental? I don’t think it is always, some cases require closer scrutiny. For instance, in the Ultimatum Game, there is a perfectly rational and egoist reason to make a fair offer, such as a 50-50 split: it is the best—from one’s point of view—solution to the trade-off between making a profit and proposing a split that the other player will accept: if you propose more, you loose more money: if you propose less, you risk a rejection. In non-market integrated culture where a 20-80 split is not seen as unfair, proposers routinely offer such splits, because they know it will be accepted.

It can also be instrumental in a more basic sense, for instance in participating to the propagation of our genes. For instance, (Madsen et al., 2007) showed that individuals behave more altruistically toward their own kin when there is a significant genuine cost (such as pain), an attitude also mirrored in study with questionnaires (Stewart-Williams, 2007): when the cost of helping augments, subjects are more ready to help siblings than friends. Finally, other studies showed that facial resemblances enhance trust (DeBruine, 2002). In each cases, we see a mechanisms whose function is to negotiate our investments in relationships in order to promote the copies of our genes housed in people who are, or look like, or could help us expand our kin. For instance, by simply viewing lingerie or picture of sexy women, men behave more fairly in the ultimatum game (Van den Bergh & Dewitte, 2006).

Many of these so-called altruistic behavior can be explained only by the operations of hyper-active agency detectors and a bias toward fearing other people’s judgement. When they are not being or feeling watched, peoples behave less altruistically. Many studies show that in the dictator game, a version of the ultimatum game where the responder has to accept the offer, subjects always make lower offers than in the ultimatum (Bolton et al., 1998). Offers are even lower in the dictator game when donation is fully anonymous (Hoffman et al., 1994). According to the present framework, it would be because there is no advantage in being fair.

When subjects feel watched, or think of agents, even supernatural ones, they tend to be much more altruistic. When a pair of eyes is displayed in a computer screen, almost twice as many participants transfer money in the dictator game (Haley & Fessler, 2005), and people contribute 3 times more in an honesty box for coffee' when there is a pair of eyes than when there is pictures of a flower (Bateson et al., 2006). The sole fact of speaking of ghosts enchances honest behavior in a competitive taks(Bering et al., 2005), while priming subjects with the God concept in the anonymous dictator game (Shariff & Norenzayan, in press).

These reflections also applies to altruistic punishment. First, it is enhanced by an audience. (Kurzban et al., 2007) showed that with a dozen participants, punishment expenditure tripled. In the trust game, players apply learned social rules and trust-building routines, but they hate when cheater enjoy what they themselves refrain from enjoying. Thus it feels good to reset the equilibrium. Again, appareant altruism is instrumental in personal satisfaction, at least in some occasions.

Hardy & Van Vugt, in their theory of competitive altruism suggest that

individuals attempt to outcompete each other in terms of generosity. It emerges because altruism enhances the status and reputation of the giver. Status, in turn, yields benefits that would be otherwise unattainable (Hardy & Van Vugt, 2006)

Maybe agents are attempting to maximize a complex hedonic utility function, where the reward and the losses can be monetary, emotional or social. A possible alternative approach is what I call ‘methodological hedonism’: let’s assume, at least for identifying cognitive mechanisms, that the brain, when in function normally, tries to maximize hedonic feelings, even in moral behavior. We use feelings to anticipate feelings in order to control our behavior toward a maximization of positive feelings and a minimization of negative ones. The ‘hot logic’ of emotions is more realist than the cold logic of traditional game theory but still preserve the idea of utility maximization (although “value” would be more appropriate). In this framework, altruistic behavior is possible, but need not to rely on altruistic cognition. Cognitive mechanisms of decision-making aims primarily at maximizing positive outcomes and minimizing negative ones. The initial hedonism is gradually modulated by social norms, by which agents learn how to maximize their utility given the norms. Luckily, however, biological and cultural evolution favored patterns of self-interest that promote social order to a certain extent: institutions, social norms, routines and cultures tend to structure morally our behavior. Thus understanding morality may amount to understand how individual’s egoism is modulated by social processes. There might be no need to posit an innate Strong Reciprocity. Or at least it is worth to explore other avenues!

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Suggested reading:


I forgot to mention a thorough presentation and excellent criticism of Strong Reciprocity:

important papers from the Collective are:
  • Bowles, S., & Gintis, H. (2004). The Evolution of Strong Reciprocity: Cooperation in Heterogeneous Populations. Theoretical Population Biology, 65(1), 17-28.
  • Fehr, E., Fischbacher, U., & Gachter, S. (2002). Strong Reciprocity, Human Cooperation, and the Enforcement of Social Norms. Human Nature, 13(1), 1-25.
  • Fehr, E., & Rockenbach, B. (2004). Human Altruism: Economic, Neural, and Evolutionary Perspectives. Curr Opin Neurobiol, 14(6), 784-790.
  • Gintis, H. (2000). Strong Reciprocity and Human Sociality. Journal of Theoretical Biology, 206(2), 169-179.


  • Bateson, M., Nettle, D., & Roberts, G. (2006). Cues of Being Watched Enhance Cooperation in a Real-World Setting. Biology Letters, 12, 412-414.
  • Bering, J. M., McLeod, K., & Shackelford, T. K. (2005). Reasoning About Dead Agents Reveals Possible Adaptive Trends. Human Nature, 16(4), 360-381.
  • Bolton, G. E., Katok, E., & Zwick, R. (1998). Dictator Game Giving: Rules of Fairness Versus Acts of Kindness International Journal of Game Theory, 27 269-299
  • DeBruine, L. M. (2002). Facial Resemblance Enhances Trust. Proc Biol Sci, 269(1498), 1307-1312.
  • Haley, K., & Fessler, D. (2005). Nobody’s Watching? Subtle Cues Affect Generosity in an Anonymous Economic Game. Evolution and Human Behavior, 26(3), 245-256.
  • Hardy, C. L., & Van Vugt, M. (2006). Nice Guys Finish First: The Competitive Altruism Hypothesis. Pers Soc Psychol Bull, 32(10), 1402-1413.
  • Hoffman, E., Mc Cabe, K., Shachat, K., & Smith, V. (1994). Preferences, Property Rights, and Anonymity in Bargaining Experiments. Games and Economic Behavior, 7, 346–380.
  • Kurzban, R., DeScioli, P., & O'Brien, E. (2007). Audience Effects on Moralistic Punishment. Evolution and Human Behavior, 28(2), 75-84.
  • Madsen, E. A., Tunney, R. J., Fieldman, G., Plotkin, H. C., Dunbar, R. I. M., Richardson, J.-M., & McFarland, D. (2007). Kinship and Altruism: A Cross-Cultural Experimental Study. British Journal of Psychology, 98, 339-359.
  • Shariff, A. F., & Norenzayan, A. (in press). God Is Watching You: Supernatural Agent Concepts Increase Prosocial Behavior in an Anonymous Economic Game. Psychological Science.
  • Stewart-Williams, S. (2007). Altruism among Kin Vs. Nonkin: Effects of Cost of Help and Reciprocal Exchange. Evolution and Human Behavior, 28(3), 193-198.
  • Van den Bergh, B., & Dewitte, S. (2006). Digit Ratio (2d:4d) Moderates the Impact of Sexual Cues on Men's Decisions in Ultimatum Games. Proc Biol Sci, 273(1597), 2091-2095.