by Mark Pagel
The chapters of Part II show how humans have solved these problems by evolving two kinds of cooperative behavior not seen elsewhere in nature. One is the topic of Chapter 5 and centers on everyday acts of reciprocity and exchange, governed by emotions of fairness and the expectation of future interactions. The other form of cooperation—the topic of Chapter 6—balloons in complexity to a set of behaviors, peculiar to our species, of helping others even when there is no possibility of return. It is as if we are predisposed to precisely those acts of kindness that others could take advantage of. What purpose do these behaviors serve in us? Chapter 7 finishes this section by asking the question, why do we humans have such exceptionally large brains?
CHAPTER 5
Reciprocity and the
Shadow of the Future
That we owe human cooperation to conflicts of interests among people
CONFLICT AS A SOURCE OF COOPERATION IN SOCIETY
IN On Human Nature (1978), E. O. Wilson stated that “kin selection”—the helping of relatives—“is the enemy of civilization.” What could he have meant by this? We saw in the Prologue to this section how that theory understands altruism toward our relatives as a mechanism for promoting copies of our own genes, and how this simple principle can lead to remarkable and poignant acts of helping and self-sacrifice. But Wilson is right; nepotism turns out to be a simple-minded, knee-jerk, sentimental distant relation to the more cerebral, shrewd, and imaginative forms of cooperation among non-relatives that characterize human society.
Two points that immediately follow from the theory of helping relatives tell us why. One is that we are less likely to take advantage of relatives, because to do so is to exploit a little bit of ourselves. Nepotism doesn’t erase rivalries among relatives—after all, the first murder in the Bible is an act of fratricide—it just makes these rivalries less likely. The second is that we expect nepotism to fall away rapidly as our kin become more distantly related. A second cousin is sixteen times less likely than one of your siblings to share your genes. That is why we are far less likely to buy a second cousin a large birthday present, much less the person who lives down the street, than we are our own sister or brother.
Wilson’s point, then, is that we don’t expect kin selection on its own to produce the complex social arrangements we recognize as human culture—the alliances and coalitions, pacts and agreements—and we don’t expect it to produce the psychological dispositions and emotions we use to control, forgive, chivvy, and take advantage of our rivals. There is just too much commonality of interest among close relatives and too little among distant relatives to expect kin selection to produce much cooperation. It is because most animal societies have not moved beyond nepotism that they have never had to evolve the cooperative arrangements and psychology we regard as distinctive of our societies.
The difference between human cooperation and most animal cooperation is even more fundamental. Fundamentally, our nepotism is “paid for” by promoting copies of our genes, and this is why, for example, parents don’t expect something of equivalent value back every time they help their children. But our cooperation with other members of our societies is based on the idea of a social contract: when I do a favor for you, it is in the expectation that you will pay me back either immediately or at some future time. Simple as this sounds it requires a level of psychological sophistication that surpasses even the most poignant acts of nepotism. If I do something for you, how can I know you will pay me back, and what should I do if you don’t? Equally of course if I do something for you, you will be tempted not to return my favor, or perhaps return it with something of less value. In an intelligent species, this situation leads quickly to two alternatives. One is to engage in an escalating spiral of exploitation and counterexploitation as increases in intelligence and cunning are met by similar increases in one’s competitors. But the other is to accept that conflicts of interest can create opportunities for agreements that provide better returns than endless cycles of betrayal and revenge. If we choose this second course—and often we don’t—something surprising emerges: our conflicts of interest become the source of our truces, pacts, and agreements, and over long periods of time, they are the source of our institutions, laws, and morality. If you and I both want the same thing, we can fight for it, or we can strike up an agreement to parcel it out equitably. The savings we make in not fighting or in not having to devote time and energy to defending the resource against each other’s depredations often more than pay for the reduced income of dividing the riches between us.
GOD SAVE THE QUEEN
THE THOUGHT that we owe our cooperative societies and other cooperative institutions to conflicts of interest might strike us as bizarre, but conflict has been the source of complexity in the biological world since the origins of life. The first life consisted of simple strings of chemicals that could make copies of themselves, or replicate, on their own. They were probably not even DNA (or deoxyribonucleic acid)—the molecule that supports our life—but a simpler molecule known as RNA or ribonucleic acid. These simple strings would have competed for the same basic chemicals in the early primordial soup, because for a string of RNA to reproduce, or copy itself, it had first to find enough nucleic acid building blocks to create a duplicate string. One course for this early life to follow was to get better and better at finding chemicals before your rivals did, or perhaps work out ways to kill competing strings. But there was a cooperative alternative even then.
The late John Maynard Smith gave an elegant example of how competing replicators might have learned to cooperate in a way that benefited them all. Maynard Smith imagined there were four of these simple strings, one called God, another called Save, a third called The, and a fourth called Queen. We can think of them as short segments of RNA or DNA, and Maynard Smith supposed that initially they all competed to make copies of themselves. Maynard Smith supposed that by virtue of being shorter, God and The could replicate more quickly and consequently we might expect them to dominate the longer and slower-replicating Save and Queen strings, and eventually even replace them. But this wouldn’t mean God and The were safe from competition. Sometimes when they copy themselves, errors creep in and these change the word. For instance, Got and She strings might arise just by chance and they would be equally fast at replicating.
Life might have remained stuck on Got and She had natural selection not worked out how to exploit these strings’ conflicts of interest. Rewinding back to the original four, imagine it just happens by chance that the strings can help each other to replicate. There is nothing special about this; perhaps they just incidentally act as chemical catalysts of each other (for instance, gunpowder is a combination of sulfur, carbon, or charcoal, and potassium nitrate or saltpeter. In that mixture sulfur catalyzes the explosive reaction by lowering the temperature at which the other two ignite). In particular, Maynard Smith imagined that the presence of God might have catalyzed or increased the rate at which Save copied itself. Similarly, he supposed Save increases the rate at which The replicates, and so on for Queen, which in turn promotes copies of God, completing the loop. Thus, think of the four strings as comprising a continuous circular chain in which each provides a benefit to the next one along. The result of this cooperation is that more copies of all of them will be made than when they were competing, because now their efforts are coordinated in such a way that helping others is a way of helping yourself.
If this all sounds too easy, it is, because there is a problem. On their own there is no incentive for any of the strings to get better at promoting the next one in the chain. In fact, the situation is even worse than that. Each time one of these strings acquired some new mutation that made it better at affecting the next one, it would have benefited that rival, but at its own expense. Any change to one of them that improved another’s ability to copy itself would have been like digging its own grave because now there would be more copies of that other string, and they would have been in competition to find the same chemical buildi
ng blocks. Once again, then, we would expect this set of replicators to come to be dominated by God and The (or any equally short variants of them) because they can replicate the fastest.
We learn from this that natural selection will not favor naive altruism. In this case it takes the form of handing over a useful piece of technology to a rival but without any guarantee of a return. As we might expect, natural selection does favor greed in the recipient of this altruism, but even this is shortsighted because the naive altruist will quickly be driven extinct and there will be no one for the greedy recipient to take advantage of. On the other hand, imagine that one of the strings, say God, all on its own just happens to get better at using the presence of the previous string in the chain, Queen. Nothing new is required of Queen; God has simply acquired a mutation that improves its performance in Queen’s presence. God has specialized. God has got better at making more Gods. In contrast to naive altruism, natural selection will reward this specialization because by definition these new God strings will replace the older ones.
If Save now acquires a change that makes it better at using the presence of God, this too will be favored by natural selection, and for the same reason. The and Queen can also acquire changes that make them better at replicating themselves and the four molecules will have created a partnership that allows and even encourages certain kinds of specialization and a division of labor. We learn from this that natural selection will favor each of the strings getting better at using what is naturally available to it. In fact, specialization among these four replicators promotes rounds of competition, making them all get better at what they do. Each molecule benefits from making better use of what the others produce, and their dependency on each other makes it less likely one of them can “run away” and outcompete the others.
But we are not quite yet out of the woods. One of the strings might acquire a change that means it gets better at using the previous member of the chain, but it no longer affects the next one. It has become parasitic on the chain. Now, The might stop assisting Queen while receiving help from Save, and the world would fill up with these parasitic The strings that bleed the budding partnership to death. From our perspective, The’s behavior is pointless, but remember, natural selection, unlike you, does not look ahead. There is a way out of this dilemma, though. If somehow these four strings could have their fates linked such that they could only replicate when the others did, then cooperation would again be favored. Once fates are linked, the groups of four act as a single unit that must compete with other units like themselves. Now, if a string in one of these units received aid without passing it along, this would cause all of the strings, including itself, to fail.
Linking their fates might have been as simple as confining them all to one place, such as inside a cell. Natural selection will favor ever greater specialization and division of labor as cells compete against other cells, and it will reward changes that improve everyone’s outcomes. The enterprise benefits the best cooperators because together as a cell they are able to produce more total “information” or more in the way of technology than had their individual strings competed against one another. So long as their combined technology means they can produce more copies of themselves than they could have on their own, this partnership will be a success. This indeed could be a description of the early single-celled bacteria that began to colonize the Earth perhaps more than 3 billion years ago.
We can see in this simple story two fundamental messages for groups of replicators, whether they are short segments of DNA, simple bacterial cells, or even groups of people. One is that when everyone’s fate becomes linked, natural selection can powerfully favor cooperation and mutual acts of altruism over competition. The message for societies is clear: groups that can somehow come up with psychological and social mechanisms that strengthen the links among people will be at an advantage over less strongly linked groups. The second message is that conflict is an endlessly creative force of evolution because once one set of cooperative ventures arises, another might follow, and then these two might compete. There will always be a temptation to render your rivals impotent or even to destroy them, and the payoffs for doing so can be great. So, we don’t expect conflicts to disappear. But we can expect the constant force of conflict to create increasingly sophisticated acts of cooperation, not just because it is nice to be nice, but because this cooperation can serve everyone’s interests.
In our distant past, large groups of people formed into bands and then bands of bands formed into tribes and later villages or even nations. At each stage, other groups at a similar level of complexity are potential rivals, but a larger alliance can reduce conflict. The early nineteenth-century explorers of the American West, Meriwether Lewis and William Clark, whose observations on Native American tribes we saw in Chapter 1, were struck by the fluid, shifting, and opportunistic alliances among these tribes, often based on specializations one competitor could offer another. For example, the Cheyenne were at that time nomadic hunters, dependent on other tribes for corn, but they were good at making quillwork clothing and at breeding horses, and so would trade clothing and horses to other tribes for their corn.
One of the great mysteries of this daring expedition, known as the Corps of Discovery, is why the Native American tribes did not simply exterminate Lewis and Clark and their relatively small party of thirty or so permanent members (some members of the expedition made trips back to Washington with news of the expedition’s progress). Remarkably, only one member of the Corps of Discovery and two Native Americans died, despite nearly continuous contact between the two sides for over two years. It seems that the promise of trade and commerce might have kept the Corps of Discovery from being slaughtered. For instance, the Teton Sioux or Lakota were the most powerful and feared tribe in the western plains. When Lewis and Clark arrived in their territory near the Missouri River, the Lakota were determined to maintain their control of trade up and down that river. They had a reputation for violence and had for years intimidated and bullied other tribes, along with Spanish, French, and other European fur trappers. A Yankton Indian chief had told Lewis and Clark that the Lakotas “will not open their ears, and you cannot, I fear open them.”
Lewis and Clark met the Lakotas near what is now Pierre, South Dakota. They had with them an African-American slave called York who was part of the Corps of Discovery. The improbability of this meeting is difficult to overstate, bringing together as it did in this remote heartland of America in 1804 representatives of three of the most distantly related peoples on the planet, whose genetic and geographical paths had been diverging for most of the previous 50,000 years. York intrigued the Lakotas, but they resisted Lewis and Clark’s attempts to pacify them with medals and other gifts. The Lakotas eventually sparked a tense stand-off with arrows notched into bows on one side and guns pointed on the other. The stand-off was only defused, and bloodshed avoided, when a Lakota chief stood down his side. This chief had realized that peace with the expedition meant they could retain their control of trade into the western interior, channeling the goods these highly technologically advanced whites would supply. Looking from that moment decades into the future, we can now see that the Lakota chief had sealed his people’s fates by allowing Europeans in. But at that moment, his decision to cooperate rather than to fight ensured the Lakotas’ prosperity for years to come.
Where raw competition often leads to survival of the simplest and fastest, or the nastiest, cooperation born of conflicting interests can give rise to complex forms (just think of our species’ solution to the crisis of visual theft). Alliances, agreements, friendships, and coalitions can often pay their way by giving all of us more returns than we could have had by going down the path of outright competition. Eventually, institutions and even norms or expectations of behavior can emerge, all aimed at controlling the debilitating bouts of betrayal followed by counterbetrayal that inevitably occur without the guiding hand of cooperation to hold them in check. An optimist would say that th
e course of our recent history has been one of increasing interdependence, cooperation, and reduced violence around the world. Together, the institutions and the norms that emerge from interdependence can reach to the highest level of worldwide cooperation. In 2010, the nation of Greece was bailed out of a financial crisis by the alliance of nations known as the European Union, followed by a similar bailout of Ireland in 2011. These nations are all economic competitors but recognize that financial instability in Greece and Ireland is bad for everyone’s economy, for the simple reason that all of the economies of the European Union trade with each other—their fates are interdependent. Looking into the twenty-first century and the rise of India and China as economic powers, it will be dependence of everyone’s economies on trade with each other that will act as the best brake on conflict.
Conflicts of interest can often lead to uneasy allies. During President Lyndon Johnson’s 1964–68 term in office, relations with his director of the FBI, J. Edgar Hoover, were tense. Hoover was increasingly using illegal wiretaps on telephones to gain precious evidence on other political leaders that could be used to coerce and blackmail them. Johnson worried that the wiretaps might even include his own phone and came close to sacking Hoover. But he decided against it, trenchantly concluding, “I would rather have him inside the tent pissing out than outside the tent pissing in.”
FOUR WAYS TO BE SOCIAL AND
THE SHADOW OF THE FUTURE
IN 1981, Robert Axelrod and William Hamilton chose to phrase the case for cooperation differently from President Johnson, proclaiming: “Many of the benefits sought by living things are disproportionately available to cooperating groups.” They are right, but as we saw with the God-Save-The-Queen example, the trick of getting cooperation to work is somehow to contain the conflict before it consumes the riches that could otherwise be shared. This can prove surprisingly difficult to achieve and might be why, outside of our own species, cooperation beyond the family is comparatively rare in nature. Another problem is that there are really just four kinds of social behaviors or ways that two or more parties might behave toward one another, but only one of them benefits both parties: altruism, selfishness, spite, and cooperation.
