Literature

According to the Editors of Science, altruism “remains one of the fundamental challenges of biology”. Nowak explains the problem thus: “Evolution is based on a fierce competition between individuals and should therefore reward only selfish behavior. Every gene, every cell, and every organism should be designed to promote its own evolutionary success at the expense of its competitors.” Yet, cooperative behaviour is not hard to find in the biological world. The Neodarwinian response is to identify mechanisms of cooperation that drive altruistic behaviour. In a major review paper, Nowak discusses “the five main mechanisms of cooperation: kin selection, direct reciprocity, indirect reciprocity, network reciprocity, and group selection”.
These approaches do offer mechanistic explanations for cooperative behaviour in insects and in other animal societies. However, the real challenge for this approach is human behaviour. Boyd explains the problem thus:

“In every human society, people cooperate with many unrelated individuals. Division of labor, trade, and large-scale conflict are common. The sick, hungry, and disabled are cared for, and social life is regulated by commonly held moral systems that are enforced, albeit imperfectly, by third-party sanctions. In contrast, in other primate species, cooperation is limited to relatives and small groups of reciprocators. There is little division of labor or trade, and no large-scale conflict. No one cares for the sick, or feeds the hungry or disabled. The strong take from the weak without fear of sanctions by third parties.”

The explanations that appear to work for insects (kin selection, direct reciprocity) do not explain the indiscriminate altruism exhibited by humans. For that, the theoreticians have invoked additional mechanisms based on distinctively human traits. So, for example, indirect reciprocity linked to the human longing for reputation is highlighted as significant.

Indirect reciprocity can only promote cooperation if the probability, q, of knowing someone’s reputation exceeds the cost-to-benefit ratio of the altruistic act: q > c/b

There are additional mechanisms linked to the human tendency to develop networks and social groupings where values are different within the network or group to values outside.
So, next time you give something to help tsunami victims or children in need, just remember that it is all because you have deemed the cost-to-benefit ratio of giving to be worth the reputation it brings you.

Of course, there is another avenue for thinking about altruism: but this means going beyond neodarwinism and entertaining the thought that human beings need to be explained not only in terms of law and chance, but also in terms of design.

Five Rules for the Evolution of Cooperation
Martin A. Nowak
Science 314, 8 December 2006: 1560-1563.

Abstract: Cooperation is needed for evolution to construct new levels of organization. Genomes, cells, multicellular organisms, social insects, and human society are all based on cooperation. Cooperation means that selfish replicators forgo some of their reproductive potential to help one another. But natural selection implies competition and therefore opposes cooperation unless a specific mechanism is at work. Here I discuss five mechanisms for the evolution of cooperation: kin selection, direct reciprocity, indirect reciprocity, network reciprocity, and group selection. For each mechanism, a simple rule is derived that specifies whether natural selection can lead to cooperation.

See also: Boyd, R., The Puzzle of Human Sociality, Science 314, 8 December 2006: 1555-1556.