Question

Is altruism incompatible with natural selection? Is it feasible to measure all reciprocal altruism? Considering that not all of our cultural kin are biological kin, how might kin selection impact humans?

Answer 1

Is altruism incompatible with natural selection?

Genuine altruism appears to be incompatible with the theory of natural selection. It might be expected that natural selection would foster the development of selfish behaviour and eliminate altruism.  A form of behaviour that benefits other individuals at the expense of the one that performs the action is called altruism. The individuals that act selfishly benefit from the altruists at no cost to themselves while, the fitness of the altruist is diminished by its behaviour. But, the beneficiaries of altruistic behaviour are usually relatives that carry the same genes, including the genes that promote altruistic behaviour.

Is it feasible to measure all reciprocal altruism?

Both reciprocal altruism and kin selection involve indirect increments to inclusive fitness. Reciprocators are likely to establish long-term relations and acts of reciprocal altruism should involve indirect increments to inclusive fitness. Reciprocal altruism must involve aid that is returned to an original donor as a result of behavior that has a net cost to an original recipient. The costs and benefits are measured in terms of reproductive fitness, or expected number of offspring. An organism reduces the number of offspring by behaving altruistically, but boosts the number that other organisms are likely to produce. It is difficult to measure all of them.

Considering that not all of our cultural kin are biological kin, how might kin selection impact humans?

In humans, altruism is more likely with kin than with unrelated individuals.