Liars and Outliers (6 page)

It's not even clear that natural selection favors the society with a minimum of hawk-like behavior. Hawks have value to society. In fact, if societies are in conflict with each other, it is evolutionarily advantageous to have some aggressive individuals. When war breaks out, the society with more hawks is likely to prevail. Again, think back to the primitive world in which we evolved. If you assume, as many anthropologists do, that tribal warfare was endemic among human societies, then having a substantial percentage of hawks around was valuable. Yes, they took advantage of the doves in peacetime, but they ensured the survival of those doves in wartime. Of course, we're now stuck with too many hawks because of the evolutionary pressures of 100,000 years ago.

I'm about to lump a lot of human traits together: cooperation, altruism, kindness, trustworthiness, and fairness. They're different, but all prosocial behaviors—behaviors intended to help others—and they're the glue that holds human society together. While psychologists put fine distinctions on them, considering them as facets of a whole is more useful for our purposes. They are all precursors of trust, and what allowed us to take the concept of specialization to a level unprecedented on our planet.

Figuring out how these traits evolved is an open question. Sure, they're great for our species as a whole, but that doesn't affect evolution. What matters for evolution is whether a particular characteristic helps the reproductive success of individuals with that characteristic. Kindness might be useful for society, but if it didn't result in kind people reproducing more successfully than unkind people, it would be bred out of the species pretty quickly.

There is an obvious evolutionary advantage in trusting kin: people with whom you share genetic material. If you have a gene, then your close relatives are likely to have that same gene. A gene that, on balance, makes it more likely for you to help your close relatives pass their genes on to future generations will also be more likely to be passed on to future generations—assuming, of course, that the help it provides outweighs the cost to provide it. For example, if a lioness is genetically predisposed to suckle her sister's offspring, there's a good chance that her nieces and nephews share the genes responsible for that behavior, and will pass them on to their own offspring.

The natural world is filled with examples of animals trusting, helping, and behaving altruistically with each other. Not just ants: many insects defend their nests or hives with their lives. Some animals who live in groups and fear predation—prairie dogs, ground squirrels, some monkeys, assorted herd animals, and many birds—alert the group with an alarm call if they spot a predator. Other animals hunt in groups. Most of these examples turn out to be kin helping kin.
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Extending this tendency towards non-kin is much more difficult.
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Archaeo-logists have a four-stage model of the human process. Stage one happened 6 million years ago, when empathy and a motivation to help others developed in a common ancestor of humans and chimpanzees. Stage two began 1.8 million years ago; compassion can be seen in both short-term caring for sick individuals and special treatment for the dead. Stage three is much more recent; around 500,000 or 400,000 years ago, humans became dependent on group hunting, and started exhibiting long-term care for the injured and the infirm. Stage four occurred in modern humans starting 120,000 years ago, when
compassion extended
to strangers, animals, and sometimes even objects: religious objects, antiques, family heirlooms, etc. It probably didn't extend much past groups bigger than the Dunbar number of 150 until the
invention of agriculture
, about 10,000 years ago—I guess that's a fifth stage.

Still, that doesn't tell us how or why it eventually did.

There are two basic types of non-kin cooperation. The first is mutualism.
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In some species, unrelated individuals cooperate because together they can perform tasks they couldn't do by themselves. A pack might hunt together because it can kill larger prey than the members could individually.
Unrelated elephants
help each other move objects they could not move alone.

Within a species, there's a tendency for individuals to cooperate by limiting their behavior. In many species, males fight each other for the prize of mating with a female. Primates fight to determine who is in charge of the tribe. In my house, the two cats fight to determine who gets to sit in the sunny chair. All these fights are serious, but tend to be non-injurious and are governed by ritual: roaring contests in red deer, claw-waving in male fiddler crabs, shell-rapping in hermit crabs. This is because these
ritualized battles
are often more about getting information about the other individual than actually fighting, and a non-lethal battle is often a more survivable strategy. The Hawk-Dove game can model these types of conflicts: if the risk of being a hawk is great enough, it makes evolutionary sense to be a dove even if your opponent is a hawk, because it's more survivable to retreat than to fight.
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So maybe we became smart enough to realize that cooperation usually beat defection as a survival skill, and modified our behavior accordingly. Those who could make that trade-off were more likely to pass their genes on to the next generation. This cooperation extended slowly outwards, from the immediate family group to more distant relatives to kith to familiar strangers—and over time, to unfamiliar strangers. And that cooperation slowly turned into trust.

Intelligence alone doesn't explain our trust of non-kin, though. Raw intelligence makes people calculating, but not necessarily honest or compassionate.
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The missing ingredient is called
reciprocal altruism
. This is the second basic type of non-kin cooperation, and means that we tend to treat people as we have been treated.

Reciprocal altruism isn't limited to humans.
Vampire bats
must ingest blood every 60 hours or they'll die. If a bat can't find its own meal, a non-kin bat will often regurgitate some of its undigested blood and feed it to the hungry bat, knowing that another bat will regurgitate food for it at some later time. Then, the bats pay attention. They have
large frontal
lobes in their brains that they use to remember which other bats have shared blood with them in the past. A bat is more likely to share blood with a bat that has shared blood with it previously. Similarly, animals such as dogs, cats, horses, and some birds remember who was nice to them.

Think about our ancestors and their relationship with others living in their community. Cheating is valuable to the individual in the short term. But a person living in that community had an additional incentive not to cheat: if he did, he squandered his chance at future cooperation with his victim, and risked his reputation with the community. If the benefits of future cooperation are great enough, it makes evolutionary sense for non-kin to
help each other
if they can be reasonably sure they will be repaid at a later date.

A reasonable question, then, is whether altruism in the purest sense of the word really exists, or if it's all based on some anticipated reward or punishment. Perhaps Mother Teresa wasn't really altruistic; she expected her reward in Heaven. Perhaps our instinct to protect our children isn't really altruistic; it's because we expect them to care for us in our old age. We don't consider vampire bats altruistic; they expect repayment at some future date. Even the mother who sacrifices her life for her child might just be ensuring that her genes survive.

If we simplify, the psychological theory of
transactional analysis
holds that people expect some sort of return—either emotional or material—from their apparent altruism and kindness. So we rescue a stranger from a burning building because we expect to survive and be praised, and we give money to charity because it makes us feel virtuous. You can argue that whenever we act in the group interest, it's because we know we're better off when we do.

There's even an alternate theory that explains altruistic behavior without any need for pure, selfless altruism. Biologist Amotz Zahavi's handicap principle explains costly “signals” within species. If you're an individual of above-average fitness, it makes evolutionary sense to spend some of that surplus on costly and hard-to-fake signals to advertise that fact to a
potential mate
. This holds true for a peacock's tail and a stag's antlers, as well as for a human's apparently
altruistic acts
. So the man who rescues a stranger from a burning building is advertising his kindness and physical prowess, and the woman who gives money to charity is advertising her wealth. We do know that agreeableness is a trait desired by others in a mate;
kind people
are more likely to reproduce.

This seems an irrelevant exercise, rather like debating whether or not there is such a thing as free will.
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George Price
, one of the inventors of the Hawk-Dove game, was unable to accept altruism's selfish basis, and spent much of his later life trying to demonstrate how wrong his mathematical model was. He gave his money away to strangers, let the homeless live in his house, and eventually committed suicide from depression. I think a more optimistic viewpoint is in order. People behave in ways that are altruistic, empathic, kind, trustworthy, fair, and cooperative. We do these things even though we don't have to. Yes, we have evolved into a species that finds these traits desirable. Yes, this is primarily reciprocal. Yes, we are also intelligent and calculating, but this is precisely the point. We have the ability to decide whether to be prosocial or not, and most of us, most of the time, decide positively. And we call these behaviors “altruism,” “kindness,” and “cooperation.” We trust because others are trustworthy.

Humans seem to have evolved along these lines, overcoming the murderousness that accompanied our increasing intelligence. There is an enormous amount of laboratory research on altruism, fairness, cooperation, and trust. Experimenters have subjects play a variety of
bargaining games
where they divide a pot of money amongst themselves, with different outcomes depending on whether or not they act in the group interest or in self-interest. These have names like the Ultimatum game
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, the Dictator game
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, the Trust game
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, and the Public Goods game
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, all with many different variants designed to tease out a particular aspect of human prosocial behavior.
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The general results seem to be that:

• People tend to be fair-minded.
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  They routinely reduce their own rewards in order to be fair to other players.
  
• People tend to want to punish unfairness, even at their own personal expense.
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  We have a sense of justice and responsibility, and we react negatively to those who act contrary to that sense. In many instances people also reduce their own reward in order to punish someone whom they perceive to be as acting unfairly.
  
• People tend to follow social or cultural norms with respect to these prosocial behaviors.
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  Definitions of fairness are cultural. People are more likely to be altruistic in a game that emphasizes altruism, and selfish in a game that emphasizes selfishness. Levels of trust and trustworthiness vary across cultures.
  
• People tend to be more trusting and altruistic with people they think they know and can identify with—even just a little bit—than with anonymous strangers.
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• External factors matter a lot. In experiments, people were kinder after they
  found a coin
  , traveled up an escalator (as opposed to traveling down), or watched a video of
  flying through clouds
  (as opposed to watching a video of driving on the ground).
  

Of course—and this is important to remember—these are typical results, and there is a wide variety of behavior among individual people.
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This matches our experience in the world.

Neuroscience may also help explain altruism, most recently using
mirror neurons
. These are neurons in our brain that fire both when we perform an action
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and when we observe someone else performing the same action. First discovered in 1992, mirror neurons are theorized to be critical in imitation and learning, language acquisition, developing a theory of mind, empathy, and a variety of other prosocial behaviors.

Additionally, a large body of neuroscience research supports the notion that we are
altruistic innately
, even if we receive no direct benefit, because at a deep level we want to be. Studies using functional magnetic resonance imaging (fMRI) show that the amygdala, the primitive part of the brain associated with fear and anger, is involved in decisions about
fairness and justice
. And it's probably not an unrelated side-effect that people who observe others acting either fairly or unfairly rate the fair people as significantly more agreeable, likeable,
and attractive
than the unfair people. We treat each other altruistically because it gives us pleasure to do so.