Because of such difficulties in observation and interpretation, scientists have often employed similarly extreme measures in an attempt to “verify” homosexual intercourse. In the early 1970s, for example, a controversy arose concerning to what extent, if at all, mounting activity between male animals was truly “sexual.” As proof of its “nonsexual” character, some scientists claimed that full anal penetration never occurred in such contexts (thus equating penetration with “genuine” sexuality). Researchers actually went to the trouble of filming captive male Rhesus Macaques mounting each other in order to record examples of anal penetration; they even anesthetized the monkeys afterward to search for the presence of semen in their rectums. Needless to say, the cinematographic proof of anal penetration they obtained did little to quell any subsequent debate about whether such mounts were “sexual”—all it did was institute a revised definition of “sexual” activity. The fact that they were able to document penetration but not ejaculation simply meant that a new “standard” of sexuality could now be applied: only mounts that culminated in ejaculation were to be considered “genuine” sexual behavior. Ironically, none of these researchers were apparently aware of an earlier field report of homosexual activity in Rhesus Macaques in which both anal penetration and ejaculation were observed.113
This near-obsessive focus on penetration and ejaculation—indeed, on “measuring” various aspects of sexual activity to begin with—reveals a profoundly phallocentric and “goal-oriented” view of sexuality on the part of most biologists. Not just homosexual activity, but noninsertive sexual acts, female sexuality and orgasmic response, oral sex and masturbation, copulation in species (such as birds) where males do not have a penis—any form of sex whatsoever that does not involve penis-vagina penetration falls off the map of such a narrow definition. The fact is that both heterosexual and homosexual activities exist along a continuum with regard to their degree of “sexuality” or “completeness.” Male mammalian mounting behavior, for example, can involve partial mounting, full mounting but no thrusting, thrusting but no erection, erection but no penetration, penetration but no ejaculation, ejaculation but no penetration, penetration and ejaculation without series mounting, and so on and so forth.114 Each stage along this continuum has at one time or another been considered a defining threshold of “true” sexual behavior—often so as to exclude same-sex interactions—rather than as one possible manifestation of a broader sexual capacity that is sometimes, but not always, orgasmically (or genitally) focused.
A nonsexual component of homosexual behavior does appear to be valid in a number of species; in equally many species, there are clear arguments against various nonsexual interpretations, and some zoologists have themselves explicitly refuted nonsexual analyses.115 Overall, though, three important points must be considered in relation to nonsexual interpretations of behaviors between animals of the same sex. First, the question of causality—or the primacy of the nonsexual aspect—must be addressed. Just because an apparently sexual behavior is associated with a nonsexual result or circumstance does not mean that the sole function or context of the behavior is nonsexual. For example, female Japanese Macaques often gain powerful allies by forming homosexual associations, since their consorts typically support them in challenging (or defending themselves against) other individuals. However, a detailed study of partner choices showed that such nonsexual benefits are of secondary importance: females choose their consorts primarily on the basis of sexual attraction rather than on whether they will make the best or most strategic allies.116 Likewise, mounting (or other sexual activity) between animals of the same sex is described in many species (e.g., Bonobos) as a behavior that serves to reduce aggression or tension between the participants. Indeed, individuals who mount each other may be less aggressive to one another or may experience less tension in their mutual interaction, and homosexuality probably does serve a tension-reducing function for at least some animals in some contexts (as does heterosexuality). However, the situation is considerably more involved than this. Tension reduction is as likely to be a consequence of an affiliative or friendly relationship between individuals—a relationship that is also expressed through sexual contact—as it is to be a direct result of their sexual activity. Moreover, as some researchers have pointed out for Bonobos, the causal relationship may also be the reverse of what is usually supposed. That sexual behavior and situations involving tension often co-occur in this species can give the impression that sexuality is functioning only to reduce tension, when in fact it may also create or generate its own tension. Indeed, homosexual activity in male Gorillas often results in increased rather than decreased social tension.117
Second, even if behaviors are classified as nonsexual or having a nonsexual component, the behavioral categories to which they are assigned (aggression, greetings, alliance formation, etc.) are not monolithic. Many important questions remain concerning the forms and contexts of such behaviors—questions that are often overlooked once they receive their “classification.” Just because we “know” that a given behavior is “nonsexual” does not mean that we then know everything about that behavior. Apparently sexual behaviors between males in both Bonnet Macaques and Savanna Baboons, for example, are classified as social “greetings” interactions. Yet there are fundamental differences between these two species, not only in the types of activities involved, but in the frequency of participation, the types of participants, the social framework and outcome of participation, and so on.118 Ultimately, classifying such behavior as “nonsexual” is as meaningless, misleading, and unilluminating as many investigators claim a sexual categorization is, if it obscures these differences or fails to address their origin.
Finally, the relationship between sexual and nonsexual aspects of behavior is complex and multilayered and does not fit the simple equations that are usually applied, namely same-sex participants = nonsexual, opposite-sex participants = sexual. In many species, there is clear evidence of the genuinely sexual aspect of behaviors between animals of the same sex, using the same criteria that are applied to heterosexual interactions—for example, penile or clitoral erection, pelvic thrusting, penetration (or cloacal contact), and/or orgasm.119 In still other species there is a gradation or cline between sexual and nonsexual behaviors that defies any rigid categorization—or else there is a sharp distinction between the two, with both occurring among animals of the same sex. Most importantly, the sexual and nonsexual aspects of a behavior are not mutually exclusive. An interaction involving genital stimulation between two males or two females can be a form of greeting, or a way of reducing tension or aggression, or a type of play, or a form of reassurance, or any number of different things—and still be a sexual interaction at the same time. Ironically, by denying the sexual component of many same-sex activities and seeking alternative “functions,” scientists have inadvertently ascribed a much richer and varied palette of behavioral nuances to homosexual interactions than is often granted to heterosexual ones.120 Because heterosexuality is linked so inextricably to reproduction, its nonsexual “functions” are often overlooked, whereas because homosexuality is typically disassociated from reproduction, its sexual aspects are often denied. By bringing these two views together—by recognizing that both same-sex and opposite-sex behaviors can be all these things and sexual, too—we will have come very close indeed to embracing a fully integrated or whole view of animal life and sexuality.