Christians and traditionalists often condemn homosexual activity as “unnatural” behavior. The apostle Paul uses precisely this term. What does it mean?
If it is taken to mean that there is no homosexual behavior in the natural world, then the claim is manifestly untrue. As James Neill points out in The Origins and Role of Same-Sex Relations in Human Societies, same sex behavior has been observed “across the range of evolutionary complexity, from fish and reptiles to primates” (14). It is particularly widespread among mammals: “frequent homosexual activity has been observed for all species of mammals which have been carefully studied. Homosexual activity has been reported by scientists among rats, mice, guinea pigs, bats, porcupines, raccoons, dogs, cats, hyenas, lions, elephants, horses, donkeys, cattle, porpoises, and whales, not to mention all varieties of primates. Exclusive homosexual behavior has been found among hedgehogs, lions, dolphins, monkeys, baboons and chimpanzees, among others” (15).
If “unnatural” is taken to mean that homosexuality is rejected by most human societies, that is at least debatable. During the era of exploration, Europeans were appalled to discover that “native peoples in many areas displayed no discomfort with sexual interaction among members of the same sex, and seemed to take such behavior for granted. Early explorers were taken aback by the casual acceptance of homosexual behavior among tribal peoples and confounded by the seemingly universal presence of androgynous homosexual individuals, whom they often found playing important leadership roles in many tribes” (27).
Neill offers evidence that same-sex behavior was common in tribal societies in Central and South America, among native Americans, in Polynesia, and Africa. He writes of the “near universal appearance of same sex relationships among tribal peoples” (55-6), and sees it as evidence of “an intrinsic ambisexuality” in the evolutionary development of humans.
The claim that homosexuality is “unnatural” has weight only if “nature” is tied to a notion of proper ends and goods. The claim would then be that same-sex relations violate the purposes and aims of human sexuality. But discovering those aims and purposes apparently requires more than a study of nature.