The horror of this experience--and of similar experiences with warfare--led Potts to want to explain the cruelty of organized aggression in human history. The final product of his thinking is his book (co-authored with Thomas Hayden) entitled Sex and War: How Biology Explains Warfare and Terrorism and Offers a Path to a Safer World (BenBella Books, 2008).
Reading this book in my course on "Biopolitics and Human Nature" has stirred a lively discussion among the students.
Potts offers an evolutionary explanation for the causes of war and terrorism and for how such violence can be reduced. His argument turns on three claims.
His first claim is that young men have an evolved predisposition to "team aggression," which he identifies as the intentional coordination of young males in launching lethal attacks against members of their own species. He believes that there are only two species of social mammals showing this behavior--human beings and chimpanzees--and he explains this as showing an evolutionary history in which humans and chimps shared a common ancestral species in which young males practiced team aggression.
The primary insight for this claim came a few years after the war in Bangladesh, when Jane Goodall observed the chimps in the Gombe Stream National Park in Tanzania waging a war between two chimp communities, in which young males organized themselves into raiding parties to attack individuals in the opposing community. Through a series of ferocious attacks, the Kasakela troop eventually conquered the territory of the rival Kahama troop.
Potts offers various kinds of arguments and evidence to support his claim that such team aggression among young males has shaped human evolution. There is fossil evidence that many hominid ancestors died from warfare. There is archaeological evidence that warfare is pervasive in human history. And there is anthropological evidence that foraging bands (like the Yanomamo, for example) have engaged in such team aggression. Moreover, there is also evidence for the "warfare hypothesis" in explaining human evolution as shaped by group-against-group violence that drove the evolution of human intelligence, religion, and state-formation.
Potts' second claim is that women do not have this evolved predisposition to team aggression. Of course, women are capable of aggressive violence. But they do not generally organize themselves into raiding parties for lethal violence against their enemies.
This leads to his third claim, which is that the best way to promote peace is to empower women so that their peacemaking tendencies can counter the warmaking tendencies of men. To achieve that, women need to have equal access to political power, and they need to have control over their lives.
Most importantly, women need to have freedom in controlling their reproduction through family planning, which requires access to contraception and abortion. If women are free to choose how many children they will have, Potts believes, they will generally choose to have small families. This will increase their social and political influence, because this will lessen the burdens of child care. This will also slow population growth, which will have the advantage of reducing the number of young males in proportion to older males, which reduces the likelihood of young male violence.
Potts is a life-long proponent of family planning. In 1968, he became the first doctor employed on the staff of the International Planned Parenthood Federation. This has led him to travel around the world promoting family planning.
He argues that family planning is the key to reducing population growth, which is the key to reducing war and terrorism. In over-populated societies, there are too many young males who lack economic resources and who cannot find sexual mates, which creates conditions favoring young male team aggression. Potts thinks this is evident in the societies that foster terrorism. Terrorists tend to be young, unmarried males with few opportunities for success in life, who become vengeful towards dominant outgroups, and who band together to attack their enemies.
I have identified courage in war as one of the 20 natural desires that shape human nature in all societies throughout history. That's the one desire on my list that has provoked the most criticism from people who don't like the idea that war is natural for human beings and a stage for the moral virtue of courage. While I have never written enough to support my evolutionary view of war, Potts' book provides a good survey of the reasoning and evidence for war as a natural desire--particularly, among young men--that manifests both the best and the worst in human beings.
But despite my general agreement with Potts, I do see at least eleven problems with Potts' position.
(1) THE NATURAL MALE INHIBITION AGAINST KILLING.
Most men will never kill anyone. In most men, there probably is a natural inhibition against killing. Even soldiers in war are often reluctant to kill the enemy, which is why special training is required to break down this inhibition. This point is elaborated in Dave Grossman's book--On Killing--which surveys the psychology of killing in war.
But if there is such a natural inhibition against killing, then how can Potts argue that young men are predisposed by their evolved nature to team aggression? Potts' answer is that evolution has given us an "empathy switch," so that "we seem to have an innate mental ability to treat our fellow humans with either great compassion or cold disregard, depending on whether we've assigned them to ingroup, or out" (70). The difference between men and women is that for young men, on average, it's easier to turn off the empathy switch when they think they're confronting an outgroup.
(2) VIOLENT WOMEN.
Potts notes the many historical examples of female violence in war. There are female suicide bombers and "warrior Amazons." Women have fought in military units. And in the American military, women are taking ever larger roles that take them into combat. Although this might seem to deny Potts' claim about sex differences in team aggression, he can answer by arguing that women engaging in team aggression are exceptional cases. We might see the behavioral profiles of men and women as two overlapping bell-shaped curves, so that despite the overlapping, we can still see the difference in their central tendencies.
(3) THE BONOBO PROBLEM.
Of the four extant great ape species--gorillas, orangutans, chimpanzees, and bonobos, chimps are the only species that shows male coalitional violence like that of human beings. The contrast is especially evident with bonobos, who have never been observed engaging in lethal violence, and who seem to show a "make-love-not-war" policy enforced by the females banding together to dominate over the males. That's why some feminists and pacifists suggest that if bonobos are closely related to humans, this should deny the claim that human violence is an evolved trait.
It's not clear to me that Potts has an adequate answer to this. He asserts that "team aggression died out in bonobos, while persisting in Pan troglodytes and Homo sapiens" (129). But this remains mere speculation. The problem here is that there is too little known about bonobos to reach clear conclusions on this issue.
(4) CULTURAL CIRCUMSTANCES.
The most common criticism of Potts is likely to be that his biological explanation of war and terrorism does not recognize the importance of cultural circumstances in shaping violent behavior. But, actually, Potts emphasizes that while the behavioral predisposition to team aggression is an evolved trait of men, the expression of that predisposition is determined by economic and social circumstances. So, for example, when there is a high proportion of young males in a society who lack resources and lack access to sexual partners and feel resentment towards a dominant outgroup, this is a social breeding ground for terrorism or street gangs. Consequently, we can control the predispositions to some degree by controlling the circumstances.
(5) THE NOVELTY OF MODERN WAR.
Modern military organizations don't look much like the raiding parties of chimps or human foragers. It was not until the emergence of the state as based on an agricultural economy about 5,000 years ago that mass armies were made possible, and this is too recent in human history to be a biological adaptation.
Potts' answer to this objection is that even modern armies are based on small units--squads (9-15 men) and platoons (45-70 men)--because the the psychology of team aggression still requires that young men see themselves as a "band of brothers" with a sense of camaraderie that can only arise in small units comparable in size to a chimp raiding party. This is true even though modern bureaucracy allows these small units to be organize hierarchically into massively large military organizations.
(6) SANGER AND EUGENICS.
As a proponent of family planning, Potts sees himself in the tradition of Margaret Sanger, who was the founder of the modern family planning movement. But in his praise of Sanger, he is silent about her dark side: she was a proponent of eugenics and sterilization for the "unfit." Although this might seem like a minor point, it's important as an indication of Potts' failure to be candid about the historical connections between family planning and eugenics.
(7) THE BREEDING OF FUNDAMENTALISTS.
Potts is disdainful of religious belief, and particularly, fundamentalist religious belief, because he see religious fundamentalism as opposed to modern science, which is, for him, the voice of reason in the world. But there's a problem here that he doesn't acknowledge. He likes to think that modern scientific rationalism will prevail in its battle with religious fundamentalism. And yet, he notes that religious believers tend to have much higher birth rates than secular people. If that's the case, doesn't that mean that eventually fundamentalist religious believers will prevail, just by virtue of their greater growth in population? Potts never confronts this problem for his argument.
(8) THE JULIAN SIMON PROBLEM.
Potts' argument for family planning to reduce population is based on the reasoning of Thomas Malthus that population growth must lead to a social collapse from the exhaustion of scarce resources. Malthusian doom pervades Potts' book, because he sees all of life as governed by competition over scarce resources. In taking this position, Potts never confronts the serious criticisms of the Malthusian view of the world. In particular, Potts never explicitly responds to the arguments of those like Julian Simon who insist that, on the whole, population growth is more a boon to humanity than a burden, because human beings add to resources through their productivity and their ingenuity. In his book The Ultimate Resource, Simon showed how the data of history refute the gloomy predictions of the Malthusians.
As far as I can see, there is only one paragraph on this point in Potts' book. He writes:
Free-market economists make up yet another important force from the right, arguing that population growth is good because growing markets create prosperity. They tend to believe that as young people reach working age they will contribute to the economy, even though the empirical evidence, as we have seen, is that in countries with rapid population growth young people merely join the lines of the unemployed. Many economists also claim that natural resource scarcities can be compensated for by technologies and price adjustments, and they too have been influential in reducing U.S. political interest in international family planning assistance. (327)
This is all he has to say. He is silent about the extensive evidence provided by Simon (and by others like Bjorn Lomborg and Matt Ridley) supporting the claim that when markets are free, population growth is generally beneficial.
Potts should at least say something about Simon's famous bet with Paul Ehrlich. In 1980, Simon bet Ehrlich $10,000 that the prices of a list of scarce metals would be lower by 1990, while Ehrlich predicted that the growing scarcity of these metals would produce much higher prices. Simon won the bet.
(9) STONE AGE EMOTIONS.
Potts shows how "Stone Age emotions" govern politics. For example, he argues, the "war on terror" as a response to the 9/11 terrorist attacks was an irrational expression of those "Stone Age emotions." The wars in Afghanistan and Iraq were not in the national security interests of the United States. But they were justified by President Bush who appealed to the natural emotional predisposition to team aggression in response to threats from a dangerous outgroup. Instead of yielding to such emotions, Potts claims, we should act by a "cool, objective analysis of risk" like a "dispassionate super computer" (174).
But how is this possible, if "an unemotional response is impossible" (113)? Although Potts often recommends that pure, dispassionate reason should suppress our "Stone Age emotions," he also says that we need to extend our evolved emotions of empathy from the ingroup to the outgroup (166-67, 238, 258). Moreover, in a few passages, he agrees that "the building blocks of human morality are emotional as well as cognitive" (361). Isn't it more realistic to appeal to the moral emotions of empathy, while extending them to ever wider groups, than to try to totally suppress the emotions under some dispassionate Kantian Reason? Isn't this extension of empathy (or "sympathy" as Hume, Smith, and Darwin called it) the psychological basis for "human rights" and humanitarian concern? This would seem to be more compatible with Darwin's view of the moral sense based on sympathy and with the moral psychology of the emotions developed by Darwinian psychologists today.
(10) THE JUSTICE OF MALE HONOR.
Potts gives some attention to the historical movements for abolishing slavery, for standards of just war, and for humanitarian conceptions of human rights, which have put some limits on the cruelty of war. But he does not comment on the fact that these movements have been led by men as well as women. Doesn't this show that the extension of empathy beyond narrow ingroups can be rooted in male moral psychology? Can't we see the traditional standards of just war as expressions of the manly love of honor and the desire to elevate warrior honor above brutish cruelty? If so, then this shows how the taming of manly aggression might come not just from womanly compassion but also from manly chivalry.
(11) THE MANLY HUMANITARIANISM OF SCIENCE.
Potts appeals to modern science as promoting a cosmopolitan community of rational understanding that can check the parochial predispositions of male team aggression. He writes: "Science, with its intrinsic honesty and its rejection of the supernatural as an answer to real world events, has proved the only medium in history capable of linking women and men of all cultures and all races in a common understanding of the real world" (360). But Potts doesn't ponder the fact that, for most of its history, modern science has been dominated by men. Doesn't this show another way in which the natural dispositions of some men--in this case, the Socratic desire for intellectual understanding--can be turned against male violence?
Some related posts can be found here, here, here, here, here, here, here, here, and here.