What experiences led you to explore connections between sex and war?
I grew up in England during the Second World War in an area with several bomber bases. There were all these wonderfully brave young men. We used to see them in church. Their job was to drop bombs on Germany, bombs that would kill women and children. And of course many of them died in the effort. From a young age, then, I asked, “Why do people do this sort of thing?”
But wars are carried out by states, not small teams.
War builds on innumerable small episodes of team aggression. Wars are fought by small teams: the crew, the squad, the ten people in the trench with you. The state manipulates and organizes that, but at the level of the individual aggressor it’s still the same basic behavior.
Isn’t violence common in many species?
A lot of animals are violent for all of the obvious competitive reasons, but team aggression, which is a very costly behavior, occurs when teams of adults, almost always males, attack and kill individuals of the same species. It depends on being an intelligent social animal that has a territory and resources to guard and enlarge. For millions of years, it was an adaptive behavior: it gave a man more resources. A man with more resources would attract more sexual partners and therefore have more offspring and pass on more genes, which is what evolution is all about. Evolution is not good or bad; it’s just what works. It gives us some marvelous things, like the human eye, and some ugly things, like the fact that teams of men in the prime of life band together to murder others.
Why in teams?
Originally, the men would have been related to each other, but in the modern world a kinship can be formed through boot camp and other rituals of bonding. In the Gaza Strip, some terrorists were all members of the same football team, so they felt as if they were a “band of brothers,” as Shakespeare put it. Men in the foxholes told William Manchester that they fought not for flag or country, but for one another.
Women don’t do this?
Women will fight very bravely if they or their children are threatened, but we could not find a single example in the whole of human history where women have banded together spontaneously and systematically and deliberately gone out to kill other human beings.
Do women play a part in your theory of the sources of war-making?
Yes. Historically, women would be drawn to men with more resources. We still see this today, most starkly in situations such as poor women who went to Somalia to marry pirates, who were newly and publicly wealthy.
Does your book, then, present a pessimistic view of human beings?
It is both pessimistic and optimistic. Saying we have an innate predisposition to kill our neighbors is a somber hypothesis. But we’re doing it less frequently than we used to, which means we look at the world in a very different way now. Most people will say that the twentieth century was the most violent in human history, but in fact it was probably the most peaceful. If we look at deaths by team aggression against total population size, we’re getting much less violent. Unfortunately we also have many more low-cost technologies, like improvised explosive devices, and many more powerful technologies, i.e., weapons of mass destruction, for killing each other. So there is urgency.
Are you saying that we have to make war? We can’t help ourselves?
No. We don’t have to do it, but I think we will more effectively deal with our violent nature if we understand it as a universal attribute from the evolutionary history of our species rather than an aberration.
So, just because a predisposition developed over a vastly long period of time because it was adaptive doesn’t mean it is permanently adaptive?
Indeed. As conditions change, it may become less adaptive, and that is certainly what I believe about war. Team aggression at the level of killing has no purpose now, but it emerges nonetheless. The evolution of our bodies is very slow, so something that took tens of thousands of years to evolve is still there to be dealt with, even after it has no seeming purpose. It’s helpful and enlightening to look at where we’ve come from in evolution. Then we can better define the things we don’t like, and ask whether we can do anything about them. We can only do that if we’re honest about where they’re really coming from. For example, if we persist in the naïve idea that all violence is culturally determined and we obscure the differences between men and women, that’s not going to get us anywhere.
So, what is going to get us somewhere?
Well, I know it sounds simplistic, but nonetheless it’s important for men to have healthy outlets for this behavioral predisposition. It must be respected. Team sports have all the elements of bonding and aggression that are the key elements in war. Also, doing activities together like climbing a mountain can draw on the same impulses. The mountain is the enemy. It satisfies some of the same urges. Yes, there are dangers, but they are more controllable than the dangers of real war, where a lot of people get killed.
What about the role of women?
It must be said, without being vulgar, that human sexual behavior is very asymmetrical. A woman has only a few pregnancies in a lifetime, whereas, all things being equal, a man could have hundreds of children in a lifetime. Gestation and child-rearing give women an inherent orientation to long-range decisions. Also, men are evolved to take risks and be territorial. Women lived in the territory carved out by men. They benefited more from in-group cooperation and social stability than out-group hostility. As a result, they tend to take a longer view and to seek consensus. As we said in the book, “If evolution provides the poison root of warfare, it has also supplied an important antidote. We overlook women’s powerful evolutionary heritage at our collective peril.”
What is that antidote?
For one, empower women with education and more opportunities and thereby also increase the number of women leaders, the number of women in parliaments and legislatures.
How do reproductive rights play a role?
We must have energetic efforts to support reproductive autonomy. When women can control their own fertility, family size begins to fall. As family size falls, education and development increase, as does the advancement of women’s role in society. Throughout the world there is plenty of demand for family planning on the part of women, but the evolved male drive to control female reproduction often stands in the way. Male theologians, male legislators, and conservative male doctors create and maintain the barriers to family planning. All in all, then, energetic efforts at empowerment of women will mitigate the effects of the warring nature we have inherited. Peace breaks out when women have more control over their bodies and more influence in their societies.