Sex at Dawn полностью

Many economists have forgotten (or never understood) that their central organizing principle, Homo economicus (a.k.a. economic man), is a myth rooted in assumptions about human nature, not a bedrock truth upon which to base a durable economic philosophy. When John Stuart Mill proposed what he admitted to be “an arbitrary definition of man, as a being who inevitably does that by which he may obtain the greatest amount of necessaries, conveniences, and luxuries, with the

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smallest quantity of labour and physical self-denial,” it’s doubtful he expected his “arbitrary definition” to delimit economic thought for centuries. Recall Rousseau’s words: “If I had had to choose my place of birth, I would have chosen a state in which everyone knew everyone else, so that neither the obscure tactics of vice nor the modesty of virtue could have escaped public scrutiny and judgment.” Those who proclaim that greed is simply part of human nature too often leave context unmentioned. Yes, greed is part of human nature. But so is shame. And so is generosity (and not just toward genetic relatives). When economists base their models on their fantasies of an “economic man” motivated only by self-interest, they forget community—the all-important web of meaning we spin around each other—the inescapable context within which anything truly human has taken place.

One of the most cited thought experiments in game theory and economics is called The Prisoner’s Dilemma. It presents such an elegant and simple model of reciprocity, some scientists refer to it as “the E. coli of social psychology.” Here’s how it works: Imagine that two suspects are arrested, but the police don’t have enough evidence for a conviction. After the prisoners are separated, each gets the same offer: If you testify against your partner and he remains silent, you’ll go free and he’ll get the full ten-year sentence. If he fesses up but you don’t, you’ll do the time while he walks free. If neither of you talks, you’ll both get six months. If you both talk, you’ll both do five years. Each prisoner must choose to snitch or remain silent. Each is told the other won’t know about his decision. How will the prisoners respond?

In the classic form of the game, participants almost always betray one another, as each sees the benefit of quick betrayal: talk first, and walk away free. But take that theoretical conclusion to a prison anywhere in the world and ask what happens to “rats.” Theory finally caught up to reality when scientists decided to let players gain experience with the game and see whether their behavior changed over time. As Robert Axelrod explains in The Evolution of Cooperation, players soon learned that they had a better chance if they kept quiet and assumed that their partner would do the same. If their partner talked, he acquired a bad reputation and was punished, in a “tit-for-tat” pattern. Over time, those players with the more altruistic approach flourished, while those who acted only in their individual short-term interest met serious problems—a shiv in the shower, maybe.

The classic interpretation of the experiment took another blow when psychologist Gregory S. Berns and his colleagues decided to wire female players up to an MRI machine. Berns et al. were expecting to find that subjects would react most strongly to being cheated—when one tried to cooperate and the other “snitched.” But that’s not what they found. “The results really surprised us,” Berns told Natalie Angier, of The New York Times. The brain responded most energetically to acts of cooperation: “The brightest signals arose in cooperative alliances and in those neighborhoods of the brain already known to respond to desserts, pictures of pretty faces, money, cocaine and any number of licit and illicit delights.”⁴

Analyzing the brain scans, Berns and his team found that when the women cooperated, two parts of the brain, both responsive to dopamine, were activated: the anteroventral striatum and the orbitofrontal cortex. Both regions are involved in impulse control, compulsive behavior, and reward processing. Though surprised by what his team found, Berns found comfort in it. “It’s reassuring,” he said. “In some ways, it says that we’re wired to cooperate with each other.”

First published in the prestigious journal Science in 1968, biologist Garrett Hardin’s paper “The Tragedy of the Commons” is one of the most reprinted articles ever to appear in a scientific journal. The authors of a recent World Bank Discussion Paper called it “the dominant paradigm within which social scientists assess natural resource issues,” while anthropologist G. N. Appell says the paper “has been embraced as a sacred text by scholars and professionals.”⁵