The Earthling

Gorilla Warfare

Does a sexually integrated military make sense for a primate species?

The current effort to sexually integrate the U.S. military is not without precedent. Consider the natives of New Caledonia in the South Pacific, who earned their place in military annals by subduing and then eating the crew of a French survey ship in 1850. The men and women typically headed off for war in unison, although their roles did differ once the fighting began. The women would fall back to the rear; then, as one 19th-century observer put it, “whenever they see one of the enemy fall, it is their business to rush forward, pull the body behind, and dress it for the oven.”

OK, so these women aren’t quite the role models that proponents of sexual integration would order up from central casting. But history has provided few candidates for that job. As Maurice Davie noted in 1929 in his cross-cultural survey, The Evolution of War, “war is the business of half the human race.”

As a rule, the fact that women have not traditionally performed a given role has no bearing on their competence to perform it now. Centuries of female exclusion from academia or civil engineering haven’t rendered modern women unfit for those professions. However, male dominance of the killing business seems to have been going on for a lot longer than a few centuries–maybe long enough to have influenced human evolution, shaping the biological foundation of human psychology. If so, does that mean male and female psychology are so different that the sexual integration of the military is misguided? The question breaks down into three subquestions.

1Are men designed by natural selection for warfare? As regular “Earthling” readers may recall, the premise of evolutionary psychology is simple: Those genetically based mental traits that, during evolution, consistently helped their possessors get genes into the next generation became part of human nature. Careful thought experiments have shown that, in a context of regular violence, mental traits conducive to killing would do more for your genes than mental traits conducive to getting killed would. So if during human evolution men often fought in wars and women didn’t, then indeed men might be naturally better warriors than women.

Of course, the frequency of war in prehistory is not well recorded. (Hence the term “prehistory.”) But various hunter-gatherer societies–the nearest real-life models of the social environment of human evolution, and thus the purest observable expression of human nature–have been known to engage in intervillage raids. Australian Aborigines of the 19th century, according to one chronicler, made it a point “to massacre all strangers who fall into their power.” In some of these societies, more than a fourth of the males die violently.

And whether or not our distant male ancestors often participated in actual “war,” they probably fought other males and sometimes killed them. The warless !Kung San hunter-gatherers of the Kalahari Desert, once romanticized as The Harmless People, were found a few decades ago to have homicide rates between 20 and 80 times as high as industrialized nations. (And some of this killing is coalitional–two brothers and a friend gang up on an enemy, etc.) So, ethnographic evidence alone suggests that men could well be designed by natural selection to fight, and perhaps to do so in groups.

There is more evidence, which we’ll get to shortly. However, the policy implications of any male propensity to fight would depend on other questions. For example:

2Are women by nature shrinking violets, innately repulsed by war, incapable of violence? Hardly. Feuding Australian Aborigine women would sometimes square off and whack each other with yam sticks until somebody intervened. Among the Ainu, the indigenous hunter-gatherer people of Japan, women would go to war and actually fight, though only against other women.

Even when women aren’t combatants, they hardly shy away from the thought of war, or from its gore. Among the Dayak of 19th-century Borneo, women would surround a returning warrior, singing songs of praise, while the head of one of his victims sat nearby on a decorative brass tray. Among the Yanomamo of South America, women watch the one-on-one “club fights” that sometimes escalate into intervillage conflicts, screaming insults and egging their men on. Among the Ba-Huana of the Congo, one 19th-century ethnographer reported, “the chief instigators of war are the women.” If their men are insulted by other men and don’t retaliate, “the women make fun of them: ‘You are afraid, you are not men, we will have no more intercourse with you! Woma, woma [afraid]! Hu! Hu! Hu!’ Then out go the men and fight.”

All told, though women as a group are less combative than men, they are not wholly averse to combat. And plainly, some women are more eager and capable fighters than some men. (I’m male, but no one has ever confused me with Charles Bronson.) So why deny high-testosterone women an opportunity to join in the fun? If there is a good reason, it has to do with our final question.

3 Why do men fight so much? Here we come to a problem that will prove stubborn if the military tries to sexually integrate ground combat forces such as the infantry. The problem isn’t so much that men are designed by natural selection to fight as what they’re designed to fight over: women.

Even today, Yanomamo men raid villages, kill men, and abduct women for procreative purposes. Moreover, tough, mean men enjoy high social status, which attracts women and helps the men get genes into the next generation. The anthropologist Napoleon Chagnon has shown that Yanomamo men who have killed other men have more wives and more offspring than average guys.

It’s not just a question of men disinclined to violence getting killed off. Two men might fight over a woman until one man submits and the winner gets the woman. Or, men might fight for seemingly nonsexual reasons, but the winner still enjoys the high social status that wows the ladies. Indeed, it’s possible that non-lethal violence has done more to shape the male propensity for violence than simple killing has.

Male combat is common among primates. It is the reason that, in many primate species, males are so much bigger and stronger than females. Indeed, the more polygynous the species–that is, the more females a dominant male can sexually monopolize–the larger the size difference between the sexes. The toughest male gorillas get a whole harem of females to themselves, and the wimpiest get zilch. Eons of combat over such high genetic stakes have led to males that are about twice the size of females. In our species, the more modest but still marked difference in size and strength between men and women is hard evidence that violence, whether lethal or non-lethal, has paid off for men in Darwinian terms. Among the other evidence is the fact that testosterone makes people aggressive.

The problem with fielding a sexually integrated army of gorillas wouldn’t be that the females can’t fight. Try stealing a female gorilla’s baby and see how you fare. The biggest problem is that if you put three male gorillas together with one unattached female, esprit de corps will not ensue.

Yes, of course human males are better at controlling their hatreds and rivalries than gorilla males are. But are humans so good that it makes sense to sprinkle a few women into a group of infantrymen and send them all off to war, where everyone’s prospects for survival will depend on their solidarity? Hoping (even subconsciously) that one of your comrades will die seems a poor frame of mind to carry into battle.

Does the same argument apply to nonmilitary workplaces? Doesn’t sexual integration sow dissension there as well? I’d say that any downside to sexually integrating nonmilitary workplaces is not severe enough to restrict the rights of women (or men). And–in many workplaces–there may be a big upside to sexual integration. But the military is special. The cost of dissension is death, not lower earnings. (And during big wars, when the draft is on, many of the victims are people who didn’t volunteer for the job. That’s one big difference between this issue and the issue of sexually integrating police forces.)

This logic has no direct bearing on the currently topical issue of sexually integrated basic training. The troops that take basic together don’t go off to war together, so their bonding isn’t a matter of life and death. Still, basic training is meant to model some of the rigors of war, and it turns out to be a useful model indeed: The complaints of sexual harassment that deluged the Army after the Aberdeen scandal (which itself didn’t involve basic training) show how male and female psychology can complicate life for a sexually integrated army. Obviously, the more conspicuous problems–men propositioning women, for example–can be minimized with sufficiently harsh punishment. But the underlying psychological forces will still be there, taking their toll. And remember: When soldiers go from training camps to actual war, things get more primitive, not less.

One can imagine combat roles for women that wouldn’t fly in the face of human nature. (Why not try?) But reflecting on human nature doesn’t seem to be a common pastime at the Pentagon. Sexually integrating ground combat forces is now favored by one assistant secretary of the Army. The secretary himself, Togo West, has said he is open to the idea. And already combat forces are somewhat integrated in the Air Force (squadrons of pilots) and Navy (ship crews). (These things, though, as integrating the infantry would be.) Given the stakes, shouldn’t such decisions be informed by some knowledge of sexual psychology? Or, instead, we could just wait for a war and use 20-year-olds as guinea pigs in a poorly researched social experiment.