Biological Exuberance: Animal Homosexuality and Natural Diversity

These examples demonstrate that, at least in some nonhuman primates, homosexual (as well as heterosexual) relations are subject to various social prohibitions regarding choice of appropriate partners, especially where relatives are involved. These choices are not due to instinct (i.e., avoidance of an activity that would yield harmful genetic effects), because no offspring result from such relations, and because not all incest taboos are identical. Nor are they simply a “carryover” from heterosexual taboos, because same-sex and opposite-sex relations often have different prohibitions. Crucial distinctions exist between species, populations, and even between heterosexual and homosexual activity in the same species, concerning “allowable” incestuous relations—differences that cannot be attributed solely to biological (genetic) factors. Only some relatives actually “count” as related for the purpose of incest taboos, and which individuals are “tabooed” is, to a large extent, arbitrary. In other words, primates must learn what sort of kinship system(s), if any, govern sexual associations—both homosexual and heterosexual—in their social group. While the occurrence and expression of same-sex activity in these animals very likely has an instinctual or genetic component as well, homosexual relations exhibit important “cultural” characteristics that probably involve a high degree of social learning. “Taboos” exist in animals, and homosexuality is one area where such prohibitions manifest themselves in particularly compelling ways.

Ritual

Where do human rituals such as taking an oath come from? In a fascinating study of Savanna Baboon social systems, primatologists Barbara Smuts and John Watanabe offer a startling answer: they suggest that such symbolic gestures might be traced to the ritualized homosexual activities that take place between male Baboons. ⁶⁹ As part of their social interactions, male Savanna Baboons perform a variety of formalized sexual and affectionate behaviors with each other, most notably “diddling,” that is, fondling of the penis and scrotum. Other ritualized homosexual activities include mounting; grabbing, fingering, and nuzzling of the rump; kissing and nuzzling of the genitals; and embracing and kissing on the head or mouth (similar activities are also found in a number of other primates, including Common Chimpanzees, Bonnet Macaques, and Crested Black Macaques). Although these behaviors undoubtedly have an affectionate or “pleasurable” tactile component as well as a sexual dimension, they have also been characterized by some scientists as “greetings” interactions, and it is thought that they may serve to negotiate and solidify cooperation between males as well. Indeed, two males sometimes pair up and form a stable “coalition” with each other in which their mutual defense and aid is symbolized by the reciprocity of their ritual sexual exchanges with one another. Smuts and Watanabe suggest that sexual gestures such as diddling, which involve one male placing his most vulnerable and intimate organs literally in the hands of another, are in a sense a prototypical form of oath-swearing: one male, by his actions, is indicating his trust and commitment to cooperate with the other.

Two male Bonnet Macaques embracing each other in a “greeting” gesture. The male on the left is fondling the scrotum of the other male with his right hand, an activity also found in male Savanna Baboons, where it is known as “diddling.”