The Price of Altruism (44 page)

The possibility of selection at many levels, of course, makes the covariance equation all the more important. And so, drawn from the closet, dusted, and sparkled, the “Price equation,” as it has become known, is increasingly gaining new life. Theorists, among them notably Steven Frank, Alan Grafen, and the philosopher Samir Okasha, are finally joining in Hamilton’s enchantment, showing just how powerful a tool George invented and building further on its foundations.
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Ben Kerr and Peter Godfrey-Smith have recently even contributed a small improvent, adding a second covariance on the right hand side of the equation to make the causal structure more symmetrical and therefore more general, a development Price himself would undoubtedly very much have liked.
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Still, like any tautology, it’s sometimes unclear whether the Price equation is valuably invaluable or invaluably valuable: to really explain the natural world, it’s clear, the pristine mathematical beauty of the equation needs to be filled with the messiness of biology.
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But if the Price equation is better for framing a problem than for figuring out its messy biological details, it remains a crucial tool for understanding evolution in structured populations, where
inter
dependence is just as important as either dependence or independence. Its generality means that it can be applied to evolution not only of genes but also to other forms of nongenetic evolution, based on epigenetic or behavioral inheritance. Alongside its ability to represent selection working on different levels simultaneously, this is a major, if still untapped, attribute. Besides altruism, the Price equation has already proved useful in attacking problems as diverse as reproductive value, evolutionary epidemiology, genetic programs, human cultural evolution, rogue genes, meiotic drive, biodiversity, and ecology. And the more we think of it the more it stands a chance to help us understand many other problems.
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Hindsight is a wise master. Having thrown down the rope of game theory, it’s now apparent, George Price helped others scale Mount Modern-Evolutionary-Biology with a stamina and strength that have proved enduring. But even more important, by providing the penetrating spectacles of covariance through which to measure all other ropes, he has helped us see more clearly than ever before that we are all climbing the very same mountain. It’s a legacy that will continue to transform the view of what Darwin called the “entangled bank,” a dramatically exciting window into the complexity and grandeur of life.
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They could hardly have imagined it when they met behind the curtain at the Belasco Theatre, but William Edison “Isak” Price and Alice “Clara” Avery would have much to be proud of in their son.

What about altruism in humans: Is any of this relevant to us?

Return to the hamadryas baboons playing a prisoner’s dilemma. Imagine first that each baboon is either altruistic or selfish by no fault of its own: Each is born the way it is, and can no more change its nature than a vegetable become a fruit. But imagine further that each baboon has both capacities and can begin to
choose
whether it wants to be a Good Samaritan or a cheat. Suddenly we are in a completely new game: We have entered the world of
mind
.

It was Trivers who saw where this was heading. If cooperation and ultimately altruism are games of reciprocal good faith, what better way to police the system than to be able to detect deceit? Benevolence, he reasoned, requires a strong sense of justice, because a sense of justice is necessary in order to appreciate dishonesty. Over evolutionary time, and beginning with animals, a genuine instinct of fairness would have been born out of the need to distinguish the trustworthy from the swindlers. This has been demonstrated in recent experiments with capuchin monkeys: Experimenters rewarded monkeys with sweet grapes when the monkey handed them a stone, but when the monkeys were divided into two groups, one of which was handed grapes in return for the rocks and the other much less attractive cucumbers, many of the monkeys in the second group would not accept the offer. In fact the sense of unfairness could even be magnified: When, in return for their rocky offering monkeys were given absolutely nothing, some began pelting the experimenters with stones in outrage. Both our human sense of right and wrong and our discretion over when and where to use it are, it seems, legacies of natural selection.
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This may help to explain why we are so good at detecting cheats. A number of neat experimental designs suggest that this betrays a human cognitive bias: We are better at solving logical riddles that have to do with exposing shysters in real-life situations than we are solving the very same puzzles presented in the abstract. Whether detecting cheats also requires a system of punishment is a question that is argued. While some find punishment requisite for cooperation, others claim that it’s effective, but only for establishing dominance. True egalitarian cooperation, on the other hand, is best served by
withholding
recrimination: At least when it comes to peers (as opposed to the state), taking the law into your own hands is unprofitable.
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Whether punishment is necessary or not, it’s clear that people often cooperate altruistically even when they have absolutely nothing to gain: The classical economic assumptions of self-interest cannot explain the richness of human behavior, Adam Smith’s long shadow notwithstanding.
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This may not be all that surprising if one considers how valuable regard, and its subtler cousin, self-regard, is to human beings. But
why
should this be so?

Following in Trivers’s footsteps, the economist Robert Frank proposed that it all comes down to trust. To do well in life, our simian and hunter-gatherer ancestors needed to forsake the short-term temptation of self-interest, since they lived in small, mutually dependent groups. Emotions, or what used to be called “moral sentiments,” helped to ease the retreat from egoism by establishing commitment (“I love you and won’t leave you”) and eliciting reciprocity (“I love you, love me back!”). Since in evolutionary terms life is a game in which one seeks trusted partners to play with, emotions that trigger loyalty and altruism (even irrational ones) are adaptations for regulating behavior. According to this view we have a genuine conscience underlying our emotional repertoire in order to help us join hands with other conscientious sorts to everyone’s mutual advantage.
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But the logic is tricky. The possibility of deceit raises the probability of ever more subtle mechanisms for spotting deceit, which raises the probability for mechanisms of
self-deceit
. Trick yourself to trick another; what better way to conceal true intentions? This in fact seems rampant in unsuspecting man: Ask a hundred people whether they are above average in intelligence, or beauty or kindness or virtue, and considerably more than fifty, hand on heart, will tell you that they are. Still, if an arms race was put in place in evolution between cheaters and detectors, perhaps the result has ultimately been felicitous: After all, the best way to
seem
trustworthy and giving is to actually
be
trustworthy and giving.
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Which is it, then: pure genuine selflessness or an egoism so cunning that even the trickster is tricked? Some argue that the genuineness of goodness can be demonstrated scientifically, though their arguments seem really quite feeble. The strongest case that can be made for pure unsullied selflessness is that it is just as plausible as unadulterated egoism. Proponents call this “pluralism,” but in truth it is more of an admonition: There are questions that, however much we’d like it to, science simply cannot solve.
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Whether goodness is genuine or not, it was the father of the theory of evolution by natural selection who instructed that the moral sense has natural foundations. “Mr J.S. Mill speaks, in his celebrated work, ‘Utilitarianism,’” Darwin wrote in
The Descent of Man
in 1871,

In private, rhetorical deference could duly be abandoned: “He who understands baboon,” Darwin scribbled in his personal notebook years before, “would do more towards metaphysics than Locke.” The mind had been crafted by millions of years of evolution. If man wanted to comprehend his own morality, he’d need to take a careful look back at the animals.

Everyone says humans are special, and, undoubtedly, this is so. Even if each and every species is idiosyncratic, if uniqueness is really not unique, however we like to spin it, our culture does set us apart.
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Hamilton saw that this meant that group selection might play an even more central role in humans: The kind of cohesiveness borne by living in small hunter-gatherer groups and developing language might help solve the “free-rider” problem and would only have been strengthened by religion and lore. This left him cold: Group selection bumping whatever the opposite of altruism is to the next level was nothing to gain any solace from. For in order for true goodness to be born, a ruthless rival to the group was mandatory. This would both foster xenophobia between groups and necessitate a closing of the ranks within, a realization that led Trivers to dub Hamilton’s 1975 study his “Fascist paper.”
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It’s a sobering thought, but it needn’t always be true. A recent study in rats showed that the more a rat benefits from the altruism of a stranger rat, the more he will later act benevolently towards stranger rats himself.
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This happened in a laboratory, in rats that were trained by humans to pull a lever that released food for a stranger rat in another cage—perhaps not the best approximation of what happens in nature. But we humans constantly find ourselves in situations where complete strangers need our help. In fact the notion that as egalitarian morality spreads through education and culture to an ever-greater number of people, the costs of altruism are reduced may mean that we have developed a unique capacity for altruism. It’s true: History continues to serve up a litany of factious wars over religious and political influence.
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But this doesn’t mean things can’t change. Cheap airfare, integrated markets, the Worldwide Web, and the extinction rate of languages are just a few of the harbingers of our increasing interdependence. And even if globalism fails or infinitely worse—the promise of universal tranquillity crashes—something else may end up uniting us. A classic Hardin “tragedy of the commons,” the threat of a degrading environment, could graduate mankind to a higher level. And if Earth can serve as a genuine “vehicle,” then the environment will be a proxy for a ruthless enemy. Short of recognizing the inherent goodness in universality and peace, coming together to protect our planet may prove a saving grace for a still-fractured humanity. In the end it may even lead to an expansion of our circle of morality to other creatures besides ourselves.
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These are grand affairs. What direction history takes is known only to prophets and fools, and from the dawn of time distinguishing between the two has been impossible. Increasingly, however, science is training its gaze inward, to the brain, in search of clues to the origin of altruism. The neuroscientists Jorge Moll and Jordan Grafman placed volunteers in a functional MRI unit and asked them to imagine either donating a sum of money to charity or keeping it to themselves. They found that thoughts of generosity activated a primitive part of the brain that lights up with reference to food and to sex, a result interpreted by them to mean that altruism is as hard wired as our most basic functions.
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The psychologist Marc Hauser agrees. His research shows that all over the world people process ethical dilemmas in very similar ways, suggesting that the capacity for moral judgment, like language, should be thought of as intrinsic to our nature rather than a product of our culture. It is a well-documented fact that injuries to particular parts of the brain result in patients who seem to have lost their moral sense: Perfectly intelligent otherwise, they remain unable to tell right from wrong.
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But science is going further. In the most reductionist attempts to date to locate a “moral sense,” researchers have begun searching for genes for goodness: A team led by the psychologist Ariel Knafo, the geneticist Richard Ebstein, and their graduate student Salomon Israel gave fifty shekels to two hundred students and asked each of them to play what is called a dictator game: The person with the money, the “dictator,” must make a one-shot, nonreciprocated decision on how much of his pot to share with an anonymous “recipient.” Not surprisingly there is quite a bit of variation: some split their loot judiciously down the middle, others selfishly keep it to themselves, still others give most of the money away. What the researchers found when they genotyped the students was that there is a significant correlation between the degree of giving and the length of a tiny DNA microsatellite in and around a gene encoding for a receptor of the neurotransmitter oxytocin in the brain. The same was true for a related neurotransmitter called vasopressin. According to these studies, and however incredible, altruism is literally in (and around) our genes.
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