From Edward O. Wilson’s On Human Nature:
I suggest that we will want to give [universal human rights] primary status not because it is a divine ordinance…or through obedience to an abstract principle of unknown extraneous origin, but because we are mammals. Our societies are based on the mammalian plan: the individual strives for personal reproductive success foremost and that of his immediate kin secondarily; further grudging cooperation represents a compromise struck in order to enjoy the benefits of group membership.
A rational ant — let us imagine for a moment that ants and other social insects had succeeded in evolving high intelligence — would find such an arrangement biologically unsound and the very concept of individual freedom intrinsically evil. We will accede to universal rights because power is too fluid in advanced technological societies to circumvent this mammalian imperative; the long-term consequences of inequity will always be visibly dangerous to its temporary beneficiaries. I suggest that this is the true reason for the universal rights movement and that an understanding of its raw biological causation will be more compelling in the end than any rationalization contrived by culture to reinforce and euphemize it.
Is Dr. Wilson right? “In the end,” who knows? At present, in the United States at any rate, the biological consequences of inequity are invisible to its temporary beneficiaries.