The Origins of Political Order: From Prehuman Times to the French Revolution

by Francis Fukuyama

With regard to the first, the name of the game in biological evolution is not the survival of a given organism but the survival of that organism’s genes. This produces a regularity that was formulated by the biologist William Hamilton as the principle of inclusive fitness or kin selection, which holds that individuals of any sexually reproducing species will behave altruistically toward kin in proportion to the number of genes they share.5 Parents and children, and full brothers and sisters, share 50 percent of their genes, and so will behave more altruistically toward each other than toward first cousins, who share only 25 percent.