Where goods do not cross frontiers, armies will. How a Science of Good and Evil Reveals a Solution to Global Tribalism

In Rob Reiner’s 1992 film A Few Good Men, Jack Nicholson’s character — the battle-hardened Marine Colonel Nathan R. Jessup — is being cross-examined by Tom Cruise’s naive rookie Navy lawyer Lieutenant Daniel Kaffee, defending two Marines accused of killing a fellow soldier. He thinks Jessup ordered a “code red,” an off-the-books command to rough up a lazy Marine trainee in need of discipline, and that matters got tragically out of hand. Kaffee wants answers to specific questions about the incident. Jessup wants to lecture him on the meaning of freedom and the need to defend it: “Son, we live in a world that has walls. And those walls have to be guarded by men with guns. Who’s gonna do it? You? I have a greater responsibility than you can possibly fathom. You don’t want the truth. Because deep down, in places you don’t talk about at parties, you want me on that wall. You need me on that wall.”

The simple observation that we live in a world with walls — and have for the past 6,000 years of recorded history — implies that those walls are needed. The constitutions of states cannot completely alter the constitution of humanity. In my recently published book, The Science of Good and Evil, I present a theory on the evolutionary origins of morality in which I argue that humans evolved to be relatively moral and cooperative within groups and relatively immoral and competitive between groups. Natural selection created within-group amity and between-group enmity. The result is that we are, by nature, tribalistic; love thy neighbor has traditionally meant thy fellow in-group members. The long-term solution to many of our global problems, then, lies in expanding the circle of who we include as fellow in-group members.

Studies by anthropologists show that one of the prime triggers of between-group violence is competition for scarce resources. Once the carrying capacity of a group’s environment is exceeded, the demand for resources will exceed the supply, leading to between-group competition and war. Thus, one way to attenuate between-group violence is to increase the supply of resources to meet the demands of those in need of them. The nineteenth-century French economist Frederic Bastiat expressed it thusly: “Where goods do not cross frontiers, armies will.”

A case study can be found in the Yanomamö people of the Amazon, the so-called “fierce” people. There is good reason for the moniker because warfare has long been a part of Yanomamö life. As the anthropologist Napoleon Chagnon discovered, however, the Yanomamö are also sophisticated traders, and the more they trade the less they fight. The reason is that trade creates alliances.

If, as it is said, “the enemy of my enemy is my friend,” one of the primary means of protecting one’s group is to form alliances with other groups. Trade between groups is a powerful social adhesive. One village cannot go to another village and announce that they are worried about being conquered by a third, more powerful village, since this would reveal weakness. Instead, they mask the real motives for alliance through trade and feasting, and as a result not only gain military protection but insure inter-village peace. Most interestingly, even though each Yanomamö group could produce its own goods for survival, in fact they don’t; they set up a division of labor and system of trade. They do this not because they are nascent capitalists, but because they want to form political alliances with other groups, and trade is an effective means of so doing. The end result is that when goods cross Yanomamö frontiers, Yanomamö armies do not.

The point is this: trade evolved long before the state as a natural means of avoiding war. There is now archaeological evidence, for example, that over the past 200,000 years stone tools and other artifacts such as seashells, flint, mammoth ivory, and beads, were the objects of trade among our hominid ancestors, because they are often found hundreds of miles from where they were manufactured.
The psychology of trade probably has as much to do with forming alliances between individuals and groups as it does increasing the supply of resources, but the end result is the same: the cooperation that goes into making trade successful accentuates amity and attenuates enmity, leading to greater happiness and liberty for more people, in more places, more of the time.

Data from the neurosciences supports this thesis — cooperation leads to stimulation of the pleasure centers in the brain. Scientists at Emory University had 36 subjects play an exchange game while undergoing a functional magnetic resonance imaging (fMRI) brain scan. They found that the areas of the brains of cooperators that lit up were the same areas activated in response to such stimuli as desserts, money, cocaine, attractive faces, and other basic pleasures. Specifically, there were two broad areas dense in neurons that responded, both rich in dopamine (a neurochemical related to addictive behaviors): the anteroventral striatum in the middle of the brain (the so-called “pleasure center,” for which rats will endlessly press a bar to have it stimulated, even foregoing food), and the orbitofrontal cortex just above the eyes, related to impulse control and the processing of rewards. Tellingly, the cooperative subjects reported increased feelings of trust toward and camaraderie with their game partners.

How does trust translate to trade? At the Center for Neuroeconomics Studies at Claremont Graduate University, Paul Zak has demonstrated the relationship between oxytocin, trust, and economic prosperity. He argues that economists have shown how trust is among the most powerful factors affecting economic growth, and that since trust is directly related to neurological chemicals such as oxytocin, it is vital for national prosperity that the country maximize social interactions among its members, as well as members of other countries. Free trade is one of the most effective means of socializing, as is education, increased civil liberties, freedom of the press, freedom of association (most notably by increasing telephones and roads), and even a cleaner environment (people in countries with polluted environments show higher levels of estrogen antagonists, thereby lowering their levels of oxytocin and thus their feelings of trust).

Impoverished countries are poor, in part, because trust in the legal structures to protect business and personal investments are so low. Zak has even computed that “a 15 percent increase in the proportion of people in a country who think others are trustworthy raises income per person by 1 percent per year for every year thereafter.” For example, increasing levels of trust in the U.S. from its present 36 percent to 51 percent, would raise the average income for every man, woman, and child in the country by $400 per year, or $30,000 lifetime. It pays to trust.

Although extrapolating directly from neurochemistry to national economies is surely oversimplifying matters, what all this research tells us is that on one level we cooperate for the same reason we copulate — because it feels good. On a deeper evolutionary level, the reason cooperating feels good is because it is good for us, individually and as a species. Thomas Jefferson realized this in 1814: “These good acts give pleasure, but how it happens that they give us pleasure? Because nature hath implanted in our breasts a love of others, a sense of duty to them, a moral instinct, in short, which prompts us irresistibly to feel and to succor their distresses.”

How does trust and trade attenuate war and violence? In every case study of societies that made the transition from war to peace, there is a direct causal relationship between population size, ecological carrying capacity, and the availability and exchange of resources. The primary engine driving the shift in these ecological relationships is trade. When populations grow beyond the carrying capacity of their environments, they are forced into competition, which leads to war, which leads to alliances, which leads to trade, which leads to peace. In other words, the solution to war — that is, to move a society from a warlike existence to a peacelike existence — is not to be found in a particular type of government or religion or ideology or worldview; it is in a particular type of social process called trade. The evolutionary origin of trade may have been political alliances, but one of the unintended consequences is that trade produces a division of labor that generates more goods, for more people, more of the time.

This article was originally published in Toronto Globe and Mail.