Finally, revenge may have been useful for punishing (and reforming) “free riders,” people who enjoy the benefits of a group’s efforts without contributing to those efforts. To spur humans’ prodigious tendencies for cooperation, our ancestors had to ensure that when free riders failed to “pitch in” and make appropriate contributions to the common good, they suffered dire consequences.
With these adaptive functions in mind, it gets easier to accept the idea that revenge is a built-in feature of human nature, despite its dreadful effects in the world today. We might rightly view revenge as a modern-day problem, but from an evolutionary point of view, it’s also an age-old solution.
TRUTH #2: THE CAPACITY FOR FORGIVENESS IS A BUILT-IN FEATURE OF HUMAN NATURE
So revenge is an authentic, standard-issue, bred-in-the-bone feature of human nature. But that doesn’t imply that forgiveness is a thin veneer of civility, slapped on top of a brutish, vengeful core. Nothing could be further from the truth. In fact, when you use the conceptual tools of evolutionary science, you can’t help but conclude that our capacity for forgiveness is every bit as authentic as our capacity for revenge.
For example, there’s evidence that forgiveness is just as universal among humans as revenge is. Although Martin Daly and Margo Wilson found that blood revenge has emerged as an important social phenomenon in 95 percent of the societies they examined, my own analysis revealed that the concepts of forgiveness, reconciliation, or both have been documented in 93 percent of those same societies.
Is it possible that forgiveness and reconciliation really didn’t exist among that remaining 7 percent? The evolutionary biologist David Sloan Wilson has observed that “it is actually difficult to find descriptions of forgiveness in hunter-gatherer societies, not because forgiveness is absent but because it happens so naturally that it often goes unnoticed.” I think Wilson may be correct, and not just about hunter-gatherers but about all societies. Forgiveness and reconciliation may be so common and so taken for granted by anthropologists as to be regarded, quite literally, as nothing to write home about.
And just as with revenge, research has found that forgiveness is also widespread across the animal kingdom, offering further evidence of its evolutionary significance. More than two decades ago, primatologist Frans de Waal and a colleague published results showing that friendly behaviors such as kissing, submissive vocal sounds, touching, and embracing were actually quite common after chimpanzees’ aggressive conflicts. In fact, these were the chimpanzees’ typical responses to aggressive conflicts. The researchers observed 350 aggressive encounters and found that only 50, or 14 percent, of those encounters were preceded by some sort of friendly contact. However, 179, or 51 percent, of the aggressive encounters were followed by friendly contact. This was a staggering discovery: friendly contact was even more common after conflict than it was during conflict-free periods. Chimps kiss and make up in the same way people do.
Chimpanzees aren’t the slightest bit unique in this respect. Other great apes, such as the bonobo and the mountain gorilla, also reconcile. And it gets more interesting still, for reconciliation isn’t even limited to primates. Goats, sheep, dolphins, and hyenas all tend to reconcile after conflicts (rubbing horns, flippers, and fur are common elements of these species’ conciliatory gestures). Of the half dozen or so nonprimates that have been studied, only domestic cats have failed to demonstrate a conciliatory tendency. (If you own a cat, this probably comes as no surprise.)
So why might animals (humans included) be so willing to forgive and reconcile? Why might evolution have outfitted us with such an ability? Biologists have offered several hypotheses. I’m especially fond of the “valuable relationship” hypothesis, espoused by de Waal and many other primatologists. It goes like this: Animals reconcile because it repairs important relationships that have been damaged by aggression. By forgiving and repairing relationships, our ancestors were in a better position to glean the benefits of cooperation between group members—which, in turn, increased their evolutionary fitness.
Research with seven pairs of female long-tailed macaques offers perhaps the most striking evidence of how the value of a relationship affects whether a conflict will be reconciled. In the first phase of their experiment, researchers Marina Cords and Sylvie Thurnheer simply examined how often these seven pairs of individuals reconciled. Averaging across the seven pairs, about 25 percent of their conflicts got reconciled. In phase two, the seven pairs were trained to cooperate with each other in order to get food. If one partner wanted to eat, she had to wait until the other one wanted to eat. Then they could work together to gain access to the food. No cooperation, no food. In other words, the researchers used experimental methods to turn the macaques’ relationships into valuable relationships. After they had been trained to work together in order to obtain food, the average rate of reconciliation doubled to about 50 percent. When group-living animals are given the choice between (a) reconciling with a valuable partner who has harmed them or (b) holding on to their grudges but going hungry, they generally choose the reconciled relationship and the full belly.
Needless to say, even if natural selection has caused forgiveness and reconciliation to become universal features of human nature, that doesn’t imply that these behaviors are universally practiced in the same way or with the same frequency. There are cultural differences in what people are willing to forgive and how they go about doing it. However, it seems a safe bet that under the right social conditions, most people will be motivated to take the time and trouble to forgive. So what are those social conditions that can help promote forgiveness?
TRUTH #3: TO MAKE THE WORLD A MORE FORGIVING, LESS VENGEFUL PLACE, DON’T TRY TO CHANGE HUMAN NATURE—CHANGE THE WORLD!
Human nature is what it is: the outcome of billions of years of biological evolution, the details of which are managed by a genetic cookbook. In other words, it’s pretty well locked in.
But it’s also exquisitely sensitive to context. Human nature ensures that people are capable of a wide range of behaviors; the behaviors we actually express depend on our changing circumstances.
This is especially true for forgiveness and revenge. They both emerged as adaptive solutions to problems that humans persistently encountered during evolution, and people still encounter many of those problems today. When people live in places where crime and disorder are high, policing is poor, governments are weak, and life is dangerous, they will tend to use revenge as a problem-solving strategy. They’ll do so because revenge’s ability to punish aggressors, its ability to deter would-be aggressors, and its ability to discourage cheaters made it adaptive in our ancestral environment.
Likewise, we’ll see higher rates of forgiveness under those conditions that made forgiving adaptive in our ancestral environments. This means we’ll see more forgiveness in places where people are highly dependent on complex networks of cooperative relationships, policing is reliable, the system of justice is efficient and trustworthy, and social institutions are up to the task of helping truly contrite offenders make amends with the people they’ve harmed.
Cultural changes can also produce changes in revenge and forgiveness even when we can’t change social and environmental factors directly. This is because culture’s function, as far as forgiveness and revenge are concerned, is to help people learn rules about when it’s appropriate to forgive and when it’s appropriate to seek revenge. Indeed, research with other primates has shown that the propensity to forgive can be shaped heavily by one’s cultural experiences. Separate infant monkeys from their mothers, and they’ll grow up to be less conciliatory than is typical for their species. Raise them among individuals from a more conciliatory species, and they’ll become more conciliatory than is typical.