Can self-sacrifice be in the genes? Fallen heroes do not have offspring and the genes for heroism can be expected to disappear from a population. Yet ants, bees and termites regularly give up their lives to protect the rest of the colony. Animals emit warning cries at the risk of their lives. The answer is in kin selection. The genes of the dead individual live on in brothers and sisters.
Has kin selection altruism evolved in human beings? In other words, do the emotions we feel, which in exceptional individuals may climax in total self-sacrifice, stem ultimately from hereditary units that were implanted by the favoring of relatives during a period of hundreds or thousands of generations? For most of mankinds history the predominant social unit was the immediate family and a tight network of other close relatives.
It is true that the form and intensity of altruistic acts are to a large extent culturally determined. Human social evolution is obviously more cultural than genetic. The sociobiological hypothesis (that the underlying emotion comes from the genes) does not therefore account for differences among societies, but it can explain self-sacrifice in human beings.
Wilson distinguishes two basic forms of cooperative behavior in human altruism. Hard-core altruism directed for the benefit of others with no reward for the individual originating from kin selection. Soft-core altruism, in contrast, is ultimately selfish. The altruist expects reciprocation from society for himself or his closest relatives.
Reciprocation is the key to human society. But hard-core altruism based on kin selection is the enemy of civilization. If human beings are guided by programmed learning rules to favor their own relatives and tribe, only a limited amount of global harmony is possible.
Wilsons estimate of the relative proportions of hard-core and soft-core altruism in human behavior is optimistic. The rational calculation and selfishness of humans makes for soft-core altruism. Tribalism and ethnicity are important but their rule is not absolute.
Human beings are consistent in their codes of honor but endlessly fickle with reference to whom the codes apply. The genius of human sociality is in fact the ease with which alliances are formed, broken, and reconstituted. The important distinction is today, as it appears to have been since the Ice Age, between the in-group and the out-group, but the precise location of the dividing line is shifted back and forth with ease. There can be no altruistic perfection when groups make strong distinctions between us and them?
To the extent that principles are chosen by knowledge and reason they can oppose biology Can higher ethical values completely replace genetic evolution? Wilson thinks not. The genes hold culture on a leash but the leash is very long.