The Advantages of Gay Sex

In American culture today, there still exists a widespread fear and disapproval of homosexuality.  This taboo has fortunately lost much of its force over the last century, but it's still strong enough to make objectivity difficult for many people, scientists included.  Joan Roughgarden quotes George Barlow, a respected biologist, writing very recently:

When animals have access to members of the opposite sex, homosexuality is virtually unknown in nature, with some rare exceptions among primates.   (The Cichlid Fishes: Nature's Grand Experiment in Evolution, 2000, page 145).

Even coming from an undergraduate, this statement would reveal a surprising ignorance of field work over the last half century, but from a distinguished senior biologist it signals once again that scientists are just as capable of being blinded by their own taboos as any tribal hunter-gatherer.

What is gay sex?

Gay sex clearly involves mutual erotic stimulation by two members of the same sex, but this kind of behavior can occur in different contexts for different reasons.  It's worth distinguishing the following potential motivations for gay sex:

• Gender-indifference.  Same-sex interactions can occur when an animal doesn't particularly care what gender of partner he or she has sex with.  An example would be social sexuality among bonobos (pygmy chimpanzees). 
• Gender-preferential bisexuality.  An animal may prefer to have sex with a partner of one gender, and that preference may even include pair-bonding, but the animal may also engage in sexual interactions outside that preference.  Bighorn sheep commonly exhibit such behaviors — most male sexual activity throughout the year involves anal sex with other males — only briefly during the fall does male-female sexual activity occur, for reproductive purposes.
• Exclusive, non-reproductive homosexuality.  This is the most intriguing form of gay sex, in which an animal has such a strong preference for sex with partners of the same gender that he or she never has sex with a partner of the opposite gender, and thus never procreates. This kind of behavior occurs most commonly in species in which strong heterosexual pair bonds also occur.

To an observer who is phobic about sexual activity in general or about same-sex interactions in particular, these distinctions may not seem important — emotional reaction to sexual activity may overwhelm the observer's ability to make any distinctions at all, particularly if observing produces involuntary arousal. 

In the nineteenth century, such phobias were so entrenched as social taboos that even those scientists who didn't share them couldn't generally publish observations of a sexual nature, because anything sexual was widely thought to be "indecent." 

Such attitudes have carried over into this century to a remarkable extent, as Bruce Bagemihl documents.  He quotes primatologist Linda Wolfe:

I have talked with several (anonymous at their request)  primatologists who have told me that they have observed both male and female homosexual behavior during field studies.  They seemed reluctant to publish their data, however, either because they feared homophobic reactions ("my colleagues might think that I am gay")  or because they lacked a framework for analysis ("I don't know what it means").  If anthropologists and primatologists are to gain a complete understanding of primate sexuality, they must cease allowing the folk model (with its accompanying homophobia)  to guide what they see and report.  (in J.D.Loy et al eds., Understanding Behavior: What Primate Studies Tell Us About Human Behavior, 1991, page 130)

However, there really isn't anything to be scared of in seeing people or other animals having sex, whether it's straight sex or gay sex, and whether or not it's arousing to watch.  What's important is to try to understand how sexual behavior fits into the lives and evolution of the animals who engage in it, including us human animals. 

Gay sex abounds in nature!

Bruce Bagemihl's Biological Exuberance should forever lay to rest the myth that gay sex is a rarity in nature.  Drawing together a vast amount of field work by hundreds of biologists over the last half-century, he specifically categorizes gay interactions documented in 190 specieas, and makes reference to interactions observed in hundreds more, allowing him to assert with authority that "homosexuality is found in virtually all animal groups, in virtually all geographic areas and time periods, and in a wide varity of forms" (page 78).

But why?

Why is there so much gay sex in nature, if reproduction is so important? 

In most cases, the answer might well be, "Why not?"  Very often, gay sex doesn't get in the way of reproduction at all — even when animals seem to prefer gay sex most of the time, they participate in straight sex enough to reproduce and pass on their genes.  This explanation is termed "neutralist" because it holds that gay sex is a neutral trait from an evolutionary point of view, neither selected for nor selected against.  A variant of this is the exuberance theory that Bagemihl favors, which holds that as long as adequate reproduction takes place, a strong built-in sex drive is free to express itself in a great diversity of "extra" forms. 

Such an idea does not, however, explain the kind of gender-exclusive gay sex that results in childless same-sex pair bonds.  Such non-reproductive gay sex is found not only in humans but in a number of other specieas as well.  Given what a significant selective disadvantage applies to the genes of any individual who doesn't reproduce, and given how fine the evolutionary filter can end up being (as analyzed, for example, by James Weinreich), it seems likely that gender-exclusive gay sex must confer some kin-based genetic advantage or it would have been eliminated long ago.

This point was argued in a general way by evolutionary biologist George Hutchinson in an article in 1959, and then in 1975 by Edward O. Wilson in Sociobiology.  Roughgarden also agrees with this "adaptionist school, which holds that nearly all behaviors and traits benefit organisms and our task is to figure out how"  (Evolution's Rainbow page 145).  Her social selection theory, however, is directed at explaining the utility of same-sex interactions among a breeding population rather than at showing why non-breeding gay individuals might be selected for. 

Gay sex in humans

Humans display a vast variety of sexual behaviors.  In spite of what fearful people would like to believe, the majority of humans never have and probably never will adopt "family values" in a monolithic way.  Instead, while generally forming very strong pair bonds throughout our prehistory and history, we've also created cultures where polygyny, polyamory, polyandry, and all kinds of variants have been the norm.  As our experience with recent sex-positive subcultures shows, humans still seem quite comfortable on occasion behaving like bonobos, or even like mountain chimpanzees, or like highly creative, polymorphously perverse humans. 

The word we currently use to describe people who show indifference to gender is "bisexual."  This is a little misleading, though, because some people who have a strong gender preference in one aspect of their sex lives may not exhibit a strong preference in another.  Truly bisexual people, of which there are certainly many, really don't have a strong preference for either gender, but there are also gay people who like straight sex under certain circumstances, and straight people who sometimes enjoy gay sex.  Threatening as this may seem to our ability to pigeon-hole sexuality, such a mixture of preferences often seems to work fine in practice. 

One of the more unusual aspects of human sexuality is our propensity for forming very intense primary pair bonds — this is a trait we share with very few other mammals, and certainly not with our closest primate cousins.  Most evolutionary theorists agree that the reason we developed this trait was because human children require such a huge parental investment in order to survive.  Two parents at a minimum are often required to raise several children to maturity. 

It has been suggested that one of the key reasons menopause was selected for in humans was to free up grandparents from new and risky reproductive investments of their own so they could contribute to the survival of their grandchildren. 

Ironically, in the kind of non-competitive environment that Joan Roughgarden suggests we might have evolved in, such co-operation would not have been necessary.  Only in an world punctuated by periods of great scarcity and danger would the help of grandparents been a key to ensuring survival of a gene pool.  There is, however, a good deal of evidence to suggest that we did indeed evolve in a world that was often extremely dangerous and competitive (see the babies mean war page).

That, then, is also a context in which the survival of children could have depended on the help of other adult relatives not themselves encumbered by children.  This is the "helper" rationale for the significant proportion of non-reproductive people in human populations.  In good times, such help was unlikely to have been necessary, but during the inevitable bad times, it might well have made the difference between life and death for the children of a family or tribe. 

This gives us a reasonable basis for hypothesizing why five to ten percent of both human sexes tend to form such strong same-sex pair bonds that they don't reproduce — because by doing so, they made it more likely that children who were their kin would survive the times of war and famine through which human populations have regularly had to pass. 

So be grateful to your gay relatives!

If all the anti-gay propaganda in our culture has made you feel uncomfortable about gay sex, maybe you should take it a bit more personally — because in all likelihood, you owe your very existence to gay relatives who helped your distant ancestors survive.  Those people who want you to believe that there's something wrong with being gay are actually saying you shouldn't exist!

And while you're at it, just be aware that gay sex is not particularly different from straight sex.  It's all just sex, and remarkably sweet and innocent as human activities go — much less weird than football or crossword puzzles...