Liars and Outliers (5 page)

Some scientists believe that this increased socialization actually spurred the development of human intelligence.
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Machiavellian Intelligence Theory—you might also see this called the Social Brain Hypothesis—holds that we evolved intelligence primarily in order to detect deception by other humans. Although the “Machiavellian” term came later, the idea first came from psychologist
Nicholas Humphrey
. Humphrey observed that wild gorillas led a pretty simple existence, with abundant and easily harvested food, few predators, and not much else to do but eat, sleep, and play. This was in contrast to gorillas in the laboratory, which demonstrated impressive powers of creative reasoning. So the obvious question is: what's the evolutionary advantage of being intelligent and clever if it's not required in order to survive in the wild? Humphrey proposed that the primary role of primate intelligence and creativity was to deal with the complexities of living with other primates. In other words, we evolved smarts not to outsmart the world, but to outsmart each other.

It's more than that. As we became more social, we needed to learn how to get along with each other: both cooperating with each other and ensuring everyone else cooperates, too. It involves understanding each other. Psychologist
Daniel Gilbert
describes it very well:

We are social mammals whose brains are highly specialized for thinking about others. Understanding what others are up to—what they know and want, what they are doing and planning—has been so crucial to the survival of our species that our brains have developed an obsession with all things human. We think about people and their intentions; talk about them; look for and remember them.

This makes evolutionary sense. Intelligence is a valuable survival trait when you have to deal with the threats from the natural world. But intelligence is an even more valuable survival trait when you have to deal with the threats from other intelligent individuals. An intelligent adversary is a different animal, so to speak, than an unintelligent adversary. An intelligent attacker is adaptive. An intelligent attacker can learn about its prey. An intelligent attacker can make long-term plans. An intelligent adversary can predict your defenses and incorporate them into his plans. If you're being attacked by an intelligent human, your most useful defense is to also be an intelligent human. Our ancestors grew smarter because those around them grew smarter, and the only way to keep up was to become even smarter.
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It's a Red Queen Effect in action.

In primates, the frequency of deception is directly proportional to the size of a species' neocortex: the “thinking” part of the mammalian brain. That is, the bigger the brain, the greater the
capacity for deception
. The human brain has a neocortex that's four times the size of its nearest evolutionary relative. Eighty percent of our brain is neocortex, compared to 50% in our nearest existing relative and 10% to 40% in
non-primate mammals
.
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And as our neocortex grew, the complexity of our social interactions grew as well. Primatologist Robin Dunbar has studied primate group sizes. Dunbar examined 38 different primate genera, and found that the volume of the
neocortex correlates
with the size of the troop. He established that the
mean human group
size is 150.
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This is the Dunbar number: the number of people with whom we can have explicit and personal encounters, whose history we can remember, and with whom we can experience some level of intimacy.
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Of course, it's an average. You personally might be able to keep track of more or fewer. This
number appears regularly
in human society: it's the estimated size of a Neolithic farming village; the size at which Hittite settlements split; and it's a basic unit in professional armies, from Roman times to the present day. It's the average size of people's Christmas card lists. It's a common department size in modern corporations.

So as our ancestors got smarter, their social groups got larger. Chimpanzees live in groups of approximately 60 individuals.
Australopithecus
—our ancestor from 4.5 million years ago—had an average group size of 70 individuals. When our first tool-using ancestors appeared 2 million years ago, the group size grew to 80.
Homo erectus
had a
mean group size
of 110, and Neanderthals 140.
Homo sapiens
: 150.

One hundred and fifty people is a lot to keep track of, especially if they're all clever, sneaky, duplicitous, and—as it turns out—murderous. There is a lot of evidence—both from the anthropological record and from ethnographic studies of contemporary primitive cultures—that humans are innately quite violent, and that intertribal warfare was endemic in primitive society. Several studies estimate that 15–25% of prehistoric males
died in warfare
.
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Economist
Paul Seabright
postulates that intelligence and murderousness are mutually reinforcing. The more murderous a species is, the greater the selective benefit of intelligence; smarter people are more likely to survive their human adversaries. And the smarter someone is, the more an adversary wants to kill him—and not just make him submit, as
other species
do.

Looking at the average weight of humans and extrapolating from other animals, humans
should primarily hunt
medium-sized rodents; indeed, early humans primarily hunted small game. And hunting small game is much more efficient for a bunch of reasons.
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Even so,
all primitive societies
hunt large game: antelopes, walrus, and so on. The theory is that although large-game hunting is less efficient, the skill set is the same as what's required for intertribal warfare. The groups that excelled at large-game hunting were more likely to survive the endemic warfare that existed in our evolutionary past. Group hunting also reinforced social bonds, which are a useful group survival trait.

A male killing another male of the same species—especially an unrelated male—eliminates a sexual rival. If you have fewer sexual rivals, you have more of your own offspring. Natural selection favors murderousness. On the other hand, attempting to murder another individual of the same species is dangerous; you might get yourself killed in the process. This means fewer offspring, which implies a counterbalancing natural selection against murderousness.

It's another Red Queen Effect, this one involving murder. Evolutionary psychologist
David Buss
writes:

As the motivations to murder evolved in our minds, a set of counter-inclinations also developed. Killing is a risky business. It can be dangerous and inflict horrible costs on the victim. Because it's so bad to be dead, evolution has fashioned ruthless defenses to prevent being killed, including killing the killer. Potential victims are therefore quite dangerous themselves. In the evolutionary arms race, homicide victims have played a critical and unappreciated role—they pave the way for the evolution of anti-homicide defenses.

There is considerable debate about how violent we really are, with the majority opinion coming down on the “
quite violent
” side, especially among males from ages 16 to 24. On the other hand,
some argue
that human violence has declined over the millennia, primarily due to the changing circumstances that come with civilization. We do know it's been traditionally very hard to convince soldiers to
kill in war
, and our experience with post-traumatic stress disorder shows that it has long-lasting ill effects. Our violence may be innate, but it depends a lot on context. We're comparable
with other primates
.
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But if we are so naturally murderous, how did our prehistoric ancestors come to trust each other? We know they did, because if they hadn't, society would never have developed. People would never have gathered into groups that extended past immediate family, let alone into villages and towns and cities. Division of labor would have never evolved, because people couldn't trust others to do their parts. We would never have established trade with the strangers we occasionally encountered, let alone with companies based halfway across the planet. Friendships wouldn't exist. Societies based on either geography or interest would be impossible. Any sort of governmental structure: forget it. It doesn't matter how big your neocortex is or how abstractly you can reason: unless you can trust others, your species will forever remain stuck in the Stone Age.

The answer to that question will make use of the concepts presented in this chapter—the Red Queen Effect, the Dunbar number, our natural intelligence and murderousness—and it will make use of security. It turns out that trust in society isn't easy, and that we're still getting it wrong.

Chapter 3

The Evolution of Cooperation

Two of the most successful species on the planet are humans and leafcutter ants of Brazil. Evolutionary biologist Edward O. Wilson has spent much of his career studying the ants, and argues that their success is due to
division of labor
.
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There are four different kinds of leafcutter workers: gardeners, defenders, foragers, and soldiers. Each type of ant is specialized to its task, and together the colony does much better than colonies of non-specialized ant species.

Humans specialize too, and—even better—we can adapt our specialization to the situation. A leafcutter ant is born to a particular role; we get to decide our specialization in both the long and short term, and change it if it's not working out for us.
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Division of labor is an exercise in trust. A gardener leafcutter ant has to trust that the forager leafcutter ants will bring leaf fragments back to the nest. I, specializing right now in book writing, have to trust that my publisher is going to print this book and bookstores are going to sell it. And that someone is going to grow food that I can buy with my royalty check. If I couldn't trust literally millions of nameless, faceless other people, I couldn't specialize.

Brazilian leafcutter ant colonies evolved trust and cooperation because they're all siblings. We had to evolve it the hard way.

We all employ both cooperating and defecting strategies. Most of the time our self-interest and group interest coincide, and we act in accordance with the group norm. Only sometimes do we act in some competing norm. It depends on circumstance, and it depends on who we are. Some of us are more cooperative, more honest, more altruistic, and fairer. And some of us are less so. There isn't one dominant survival strategy that evolution has handed down to us; we have the flexibility to switch between different strategies.

One way to think of the relationship between society as a whole and its defectors is as a parasitic relationship. Take the human body as an example. Only 10% of the total number of cells in our human bodies are us—human cells with our particular genome. The other 90% are symbionts, genetically unrelated organisms.
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Our relationship with them ranges from mutualism (we both benefit) to commensalism (one benefits) to parasitism (one benefits and the other is harmed). The society of our bodies needs the cooperators to survive, and at the same time spends a lot of energy defending itself against the defectors.

Extending the analogy even further, our social systems are filled with parasites as well. Parasites steal stuff instead of buying it. They take more than their share in a communal situation. They overstay their welcome on their Aunt Faye's couch. They incur unsustainable debt, confident that bankruptcy laws—or some expensive lawyers—will enable them to bail out on their creditors when the going gets tough.

Parasites are all over the Internet. Crime is a huge business. Spammers are parasitic on e-mail. Griefers in online games are parasitic on more conventional players. File sharers copy music instead of paying for it; they're parasitic on the music industry, getting the benefit of commercial music without giving back any money in return.

Excepting the smallest and simplest cases, every society has parasites living inside it. And there is an evolutionary advantage to being a parasite as long as there aren't too many of them and they aren't too good at it.

Being a parasite is a balancing act. Biological parasites do best if they don't immediately kill their hosts, but instead let them survive long enough for the parasites to spread to additional hosts. Ebola is too successful, so it fails as a species. The common cold does a much better job of spreading itself; it infects, and in the end kills, far more people by being much less “effective.” Predators do best if they don't kill enough prey to wipe out the entire species. Spammers do better if they don't clog e-mail to the point where no one uses it anymore, and rogue banks are more profitable if they don't crash the entire economy. All parasites do better if they don't destroy whatever system they've latched themselves onto. Parasites thrive only if they don't thrive
too well
.

There's a clever model from game theory that illustrates this: the
Hawk-Dove game
. It was invented by geneticists John Maynard Smith and George R. Price in 1971 to explain conflicts between animals of the same species. Like most game theory models, it's pretty simplistic. But what it illuminates about the real world is profound.

The game works like this. Assume a population of individuals with differing survival strategies. Some cooperate and some defect. In the language of the game, the defectors are hawks. They're aggressive; they attack other individuals, and fight back if attacked. The cooperators are doves. They're pacific; they share with other doves, and retreat when attacked. You can think about this in terms of animals competing for food. When two doves meet, they cooperate and share food. When a hawk meets a dove, the hawk takes food from the dove. When two hawks meet, they fight and one of them randomly gets the food and the other has some probability of dying from injury.
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Set some initial parameters in the simulation: the value of sharing, the chance and severity of harm if two hawks fight each other, and so on. Program this model into a computer, set proportions for the initial population—50% hawks and 50% doves, for example—and let individuals interact with each other over multiple iterations.

What's interesting about this simulation is that neither strategy is guaranteed to dominate. Both hawks and doves can be successful, depending on the initial parameters. If the value of the food stolen is greater than the risk of death, the whole population becomes hawks. That is, if everyone is starving, people take what they can from each other without worrying about the consequences. Add a single dove, and it immediately starves. But as food gets less valuable (e.g., more plentiful) or fighting gets more dangerous, the population stabilizes into a mixture of hawks and doves. The more dangerous fighting is, the fewer hawks there will be. If food is reasonably plentiful and fighting reasonably dangerous, the population stabilizes into a mixture of mostly doves and fewer hawks. But unless you plug some really unrealistic numbers into the simulation—like starting out with a population entirely of doves—there will always be at least a few hawks in the mix.

This makes sense. Imagine a society made up entirely of cooperative doves. They share food whenever they meet each other, never stealing from one another. Now add a single hawk to the society. He does great. He steals food from all the doves, and since no one ever fights back, he has no risk of dying. It's the best survival strategy ever.

Now add a second hawk. The strategy is still pretty effective; if the population is large enough, the two hawks will never even meet. But as the number of hawks grows, the chance of two of them encountering each other—and one of them dying in the resultant fight—increases. At some point, and the exact point depends on the parameters, there are enough other hawks around that being a hawk is as dangerous as being a dove has become. That's the stable percentage of hawks in the population.

Aside from making fighting more deadly or food less valuable, there are other ways to affect the percentages of hawks and doves. If doves can recognize hawks and refuse to engage, the population will have fewer hawks. If doves can survive hawk attacks without losing their food—by developing defenses, by learning to be sneaky—the population will have fewer hawks. If there is a way for doves to punish hawks, the population will have fewer hawks. If there is a way for doves to do even better if they work together, the population will have fewer hawks. If hawks can gang up on doves profitably, the population will have more hawks. In general, we get fewer hawks if we increase the benefits of being a dove and/or raise the costs of being a hawk, and we get more hawks if we do the reverse. All of this makes intuitive sense, and shouldn't come as a surprise.

And while a population consisting entirely of doves is stable, you can only get there if you start the game out that way. And if you assume that individuals in the game can think strategically and change their strategies as people can—doves can become hawks, and hawks can become doves—then an all-dove population is no longer stable. A physicist would describe an all-dove population as an unstable equilibrium. Given how easily a dove can become a hawk, it's very unstable. There will always be at least a minority of hawks.

The Hawk-Dove game is a model, and not intended to explain how cooperation evolved. However, several lessons can be learned by extrapolating the Hawk-Dove game into the real world. Any society will have a mix of people who cooperate and share, and people who defect and steal. But as the penalty, or cost, for attempting to steal, and failing, increases—it could be dying, it could be being jailed, it could be something else—there will be fewer defectors. Similarly, as the benefit of stealing increases—either in the value of what the thief gets, or in the probability he'll succeed in stealing—there will be more thieves.

In the real world, there are gradations of hawkishness. One person might murder someone to take his money; another might rob a person but let him live. A third might just shortchange him in some business transaction, or take an unfair share at the family dinner. Those are all hawkish behaviors, but they're not the same. Also, no one is 100% hawk or 100% dove; they're individual mixtures, depending on circumstance.
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If the benefit of being a hawk is greater than the risk of being a hawk, then hawks become the dominant strategy. Doves can't survive, and everyone becomes a hawk. That's anarchy: Hobbes's “
war of all against all
.” In human terms, society falls apart. If we want to maintain a society based on cooperation, we need to ensure that the rate of defection stays small enough to allow society to remain cohesive.

Figure 4:
Metaphorical Knobs to Control a Hawk-Dove Game

You can think of these parameters as knobs that control the rate of defection. We might not think of it in those terms, but it's what we do all the time in the real world. Want fewer burglars? Increase the prison term for burglary, put more policemen on the street, or subsidize burglar alarms. Willing to live with more burglars? Understaff police departments, make it easier for burglars to fence stolen merchandise, or convince people to keep more cash at home.
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These are all societal pressures. So are increasing or decreasing social inequality, and teaching respect for other people's property in school.

In our world, the costs and benefits of being a defector vary over time. As we develop new security technologies, and as the defectors develop new ways around them, society stabilizes with a different scope of defection. Similarly, as we develop new systems—Internet banking, for example—and defectors develop new ways to attack them, society stabilizes with a still different scope of defection. If the police force gets better at arresting speeders, there will be fewer of them. If someone invents a radar detector or if cars handle better at higher speeds, there will be more speeders.
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We'll talk about this more in later chapters. The important point for right now is that no matter how hard we make life for the hawks among us—shunning them, removing them from society completely, making it less likely they will profit from their aggressive tactics—we will never be able to get the hawk percentage down to zero. Yes, we can make it very unprofitable to be a hawk, but if the percentage drops too low, being a hawk will become a more advantageous strategy. And because we humans are intelligent and adaptable, someone will figure that out and switch strategies.

Defectors are endemic to all complex systems. This is one of the dominant paradigms of life. We need to recognize that all of our complex human systems, whether they are millennia-old social systems or modern socio-technical systems, will always have parasites. There will always be a group of people who will try to take without giving back. The best we can hope for is to do what our bodies do, and what every natural ecosystem does: keep those parasites down to a tolerable level.