Why Does Peace Break Out?

Malcolm Potts

A military strategist once said ‘If you want peace understand war.’ We are an extraordinarily violent animal. Disturbing as it may be, there is an evolutionary explanation of that violence. However, we can also use our intelligence to overcome the propensity for warfare and, surprising as it may seem, the world is more at peace today than ever before. When we stop and deeply analyze the origins of warfare then one positive move we can make is to give women more autonomy and to make family planning universally accessible. Why would family planning help bring about peace? Before we can answer that question, a little historical and anthropological background.

Bands of Brothers

Humans are one of only three species that systematically and deliberately kills its own kind. We have been this way for literally millions of years. The fossil record, the observations of anthropologists, the excavations of archaeologists, written history as far back as it goes, and our contemporary world provide an unbroken sequence of raids, wars between city states, wars between nations, and in the 20th century wars that touched every part of the globe.

Occasionally, male elephant seals fight so viciously that one dies. This kind of killing is analogous to murder; but only human beings, one species of chimpanzee and possibly wolves and hyenas engage in team aggression, where a group of adults in the prime of life attack and kill an individual of the same species from another troop or pack.

In the Highlands of New Guinea, where people literally lived in the Stone Age until the first contact with Europeans in the 1930s, 5% to 30% of adults are killed by other human beings. The only intact corpse which has survived from the Ice Age, the famous Otzi discovered under a melting glacier in the Alps in 1991, was thought initially to be a poor shepherd who had lost his way. Then it was found that Otzi had three different human blood groups on his cloak and a flint arrow in his back.

As in the New Guinea Highlands, so among the chimpanzees that Jane Goodall studied, up to one third of adults are killed by other members of their own species. The animals that engage in team aggression are all intelligent, social, territorial, and intensely loyal to other members of their own troop or pack. Wolves and hyenas live in matriarchal societies where females are the primary aggressors. Chimpanzee and human society is nearly always patriarchal.

Same species killing in preliterate societies (as among chimpanzees) is about competition for resources. When the Anasazi culture in America’s South West collapsed about 900 years ago, competition for resources became so severe that people literally ate one another—as is attested by the demonstration of human myoglobin in coprolites (dried feces) found by archaeologists.

Men in the 15 to 29 year old age group have provided some of the best mathematicians, some of the most successful rock stars, most of the violent criminals—and almost all of the world’s warriors. Virtually all warriors, whether Greek hoplites at Marathon, draftees in World War II, or volunteers in Iraq are young men 18 to 30 years old. Women will fight bravely if attacked, but in the whole span of recorded history there is not a single documented episode of women banding together spontaneously and striding out to attack an enemy—as happens so often and so easily among men. There is a correlation between testosterone levels and violence. Without being facetious, testosterone is the ultimate weapon of mass destruction.

Modern wars can involve millions of men, but ultimately they are fought by small groups, by a dozen men in a platoon, or the crew of a bomber or a submarine. These are the band of brothers Shakespeare extols in King Henry's great speech before the Battle of Agincourt. These are the teams that William Manchester the journalist (who was also a Marine in the Pacific War) learnt, “Men, I now know, do not fight for flag or country, for the Marine Corps or glory, or any other abstraction. They fight for one another.” These teams we reward with Medals of Honor for outstanding courage, or if they are the enemy we classify as cowardly murders. It was a small team of closely bonded men (two were brothers) who attacked the United States on 9/11.

A Lethal Male Mutation

Human beings—or at least men—have a genetic predisposition to engage in team aggression against other human beings. Evolution is a series of accidents. It is not a series of ‘becauses’ but a set of ‘therefores’. It is not about what is good, just, or moral, but what works. Team aggression, I suggest, evolved because successful warriors enlarged their territories, gained access to more food which in turn meant that they could reproduce more rapidly and leave more of their genes in the next-generation—the ultimate metric of Darwinian evolution.

Human beings and chimpanzees had a common ancestor millions of years ago. When Jane Goodall first observed team aggression among chimpanzees she realized that it was a form of primitive warfare. But she also emphasized that we are not condemned to go to war. In fact, if we look not at the absolute number of deaths resulting from team aggression, but the rate of deaths per 1,000 of the population, then the twentieth century may have been the most peaceful in human history, and today's wars in the Congo and Darfur, while terrible, are limited to relatively small parts of the world.

Why would family planning help bring about peace? In Japan, as the total fertility rate fell (TFR: average number of children per woman) and the proportion of men 15 to 29 declined between 1920 and 2000, the nation moved from a centralized military regime to a liberal democracy. It would be unthinkable today, that France and Germany and Britain would go to war again as they did within living memory. Unfortunately it is highly likely that additional terrorist attacks will take place. The 9/11 Commission Report writes, “ By the 1990's, high birth rates and declining rates of infant mortality had produced a common problem throughout the Muslim world: a large, steadily increasing population of young men without any reasonable expectation of suitable or steady employment—a sure prescription for social turbulence.” In fact, with one exception, every time America has put its troops in harms’ way on the ground since 1990, it has been in a country with a total fertility rate (TFR) of 4 or greater.

Is there a way to enlarge the circle of peace?

Women Waging Peace

In 1972, the "Black September" band—an offshoot of the Palestinian Liberation Organization—gained world attention by seizing Israeli athletes during the Munich Olympic Games. Shortly afterwards, the PLO was offered observer status at the UN, and Yassar Arafat needed to rein in these militants. After much debate the PLO leadership choose to recruit 100 attractive young, unmarried Palestinian women. They asked them to join “a critical mission of the utmost importance to the Palestinian people.” They were in fact introduced to key Black September militants, who had been told that if they married they would be given $3,000, an apartment, a gas stove, a TV, and long-term employment, along with another $5,000 if they fathered a child. Black September collapsed. The men married. There was no more violence. No more suicide attacks. Arafat and the PLO leadership were so astonished they decided to test the effectiveness of their own experiment. Every so often they would offer the now-married terrorists a passport and ask them to visit a European city on an item of non-violent PLO business. None accepted. Marriage and having children had put them in a situation where even a low-risk action no longer made sense.

Unfortunately, we cannot offer all the world’s militant and angry young men a job, let alone a house and $5,000. But we can do a great deal to slow the patterns of rapid population growth which produce legions of angry unemployed young men.

A rapid rate of population growth gives a broad-based population pyramid, with more people in each of the younger age groups than in the group before. In a society with rapid population growth there are many more volatile young men age 15 to 29 than older men. In a zero population growth society, the age structure looks like the Empire State Building, with as many or more sober older men, than those in the 15 to 29 age group.

As in everything to do with war and terrorism, there is never a single explanation nor a one-shot solution. Nevertheless, population structure is worth taking seriously. Political scientists are showing that approximately one third of the probability a nation will engage in warfare, civil conflict or spawn terrorists can be explained by the population structure and the presence of large numbers of testosterone-filled young men. As population structure changes not only do countries become less violent, they also tend to become more democratic.

What Women Want

Wherever women have been offered realistic family planning choices (backed up by safe abortion) family size has always fallen. Where family planning was easy to get, as in Thailand, rural/urban and educational differentials in the use of contraception largely disappeared. By contrast, in countries where family planning is difficult to obtain and the most disadvantaged women face the highest barriers to getting family planning, as in the Philippines, then the difference in rural/urban levels of contraceptive use is large. Fewer unintended children, slower population growth, and greater autonomy for women all help make the world a safer place.

Family planning is the Philosopher’s Stone. Improving access to family planning lowers maternal mortality, reduces infant mortality, increases the number of children entering and staying in school, and accelerates economic development and the eradication of poverty. The ability to decide when to have a child is a prerequisite for every other aspect of women’s autonomy and advancement, including playing a constructive role in civil society.

The idea, over time, that the Pill may be mightier than the sword might seem naïve, were it not for the remarkable experience of the Islamic Republic of Iran. Following the Iran/Iraq war, the average Iranian women had 6 children. Those technically qualified in the government saw that population growth was outstripping economic development. The religious leaders endorsed family planning. Fifteen years later the average Iranian woman had 2 children. There was no one-child policy and no profound socio-economic change, but for the first time contraceptives became realistically available to everyone, voluntary sterilization (including vasectomy) was offered, and community health workers in the villages distributed Pills and condoms. Iran, a country which had given rise to horrendous numbers of suicidal young warriors in the late twentieth century has not produced a single suicide bomber in the twenty-first century.

The religious leaders remain in power but a growing middle class is more and more opposed to fundamentalism. Iran may acquire nuclear weapons, but its society, where more women than men are in universities, is likely to be a lot less dangerous than Pakistan, which has nuclear weapons and where in the face of rapid population growth girls remain illiterate and increasing numbers of boys attend madrassa schools.

Unfortunately, over the past two decades attention to population has slipped so far from the world agenda that decision-makers no longer understand that the provision of family planning services to all women is a major tool for social stability.

Those working in the field of international family planning have been unaware of, and often opposed to, military thinking. Military strategists have been divorced from the humanitarian desire driving much of the international family planning effort. To complicate matters, the most belligerent leaders have been furiously opposed to family planning. And many military analysts have not understood that rapid population growth is an extremely important variable that can change—and change quickly— through purely voluntary means. Like two one-eyed people going down the same path, each group ignores the existence of the other.

It is time the two got together.

Women all over the world want fewer children. All reasonable people want peace. Sex and war are linked, and we will all be much better off if we recognize these common goals.

Dr. Malcolm Potts, Bixby Professor at the University of California, Berkeley, is an obstetrician and research biologist. He has worked for four decades in many war-torn countries including Afghanistan, Egypt, Bangladesh and Angola.

Sex and War: How Biology Explains Warfare and Terrorism and Offers a Path to a Safer World by Malcolm Potts and Thomas Hayden was published by BenBella Books, Dallas in 1998. Sex and War asks the basic questions: Why is war so fundamental to our species? And what can we do about it? Malcolm Potts explores these questions from the frontlines, as a witness in war-torn countries around the world. As a scientist and doctor, Potts has worked in the trenches with women who have been brutalized in the course of war. Combining their personal experience with the latest scientific finding in primatology, genetics and anthropology, Potts and Hayden explain war's pivotal position in the human experience and how men in particular evolved under conditions that favored gang behavior, rape and organized aggression. Drawing on these new insights, they propose a rational plan for making warfare less frequent and less brutal. Jane Goodall writes “Potts and Hayden make an important contribution as they explore our evolutionary origins and make suggestions as to how human society might reduce warfare in the future." In 2009 Science magazine devoted two pages to reviewing Sex and War and the debate it has begun.

Notes: Christian Mesquida and Neil Weiner from York University in Canada have shown a correlation between civil conflict and a high ratio of men aged 15 to 29 in the population. For example, El Salvador during the time of greatest internal conflict had a much higher ratio of young to older men than a politically stable country such as Sweden. A regression analysis conducted by Mesquida and Weiner found population structure accounted for 30% of the variance in the possibility of civil conflict.

In 1986, the first U.S. government task force on terrorism, chaired by then vice president George H. W. Bush, noted how “a volatile mixture of youthful aspirations that when coupled with economic and political frustrations help form a large pool of potential terrorists.” Sixteen years later the National Academies, in Discouraging Terrorism: Some Implications of 9/11, used almost the same words, writing “many societies that foster terrorism are characterized by high population growth and large numbers of disadvantaged youth and by extreme poverty and inequality.”