Robin Hood took from the rich and gave to the poor. A recent study by a team of researchers headed up by University of California-San Diego political scientist James Fowler suggests that we may all have Robin Hood tendencies. Experimental economists and psychologists from around the world have been watching how people play various economic games as a way to probe the bases of human cooperation. One of the more interesting discoveries is that in economic games some people— altruistic punishers—will take fairly big hits to their winnings in order to reduce the ill-gotten gains of cheaters. Games with altruistic punishers elicit more cooperative behavior among players. In addition, other researchers have found that players will happily spend some of their own winnings in gambling games in order to reduce the "undeserved" winnings of other players.
In re-analyzing some earlier studies, Fowler and his colleagues suggested "that egalitarian motives are more important than motives for punishing non-cooperative behaviour." In other words, people are really more interested in enforcing income equality than they are in punishing cheaters. To tease out motives, Fowler and his colleagues devised a game in which there was no possibility of reciprocity or cooperation. Their hypothesis was that people would spend some of their incomes to equalize the incomes of other players.
In their game, participants (120 college students) were assigned to groups of four anonymous players. At the outset each received a randomly generated sum of money. The payoffs are shown to all the players who are then given an opportunity to give "negative" or "positive" tokens to other players. Each token cost one monetary unit. Giving a negative token to another player reduced the recipient's winnings by 3 monetary units and giving a positive token to another player increased the recipient's winnings by 3 monetary units. After each round, the anonymous group members were randomized to prevent reputation from influencing decisions. Keep in mind that choosing to cut or to boost the incomes of other players is costly and yields no material gain, so self-interested subjects should have no incentive to engage in it. So what happened?
Their latest study in the journal Nature reports, "Individuals who earned considerably more than other members of their group were heavily penalized." On the other hand, players who earned a lot less than other group members received substantial gifts. A majority of players (68 percent) chose to cut the earnings of other players at least once, 28 percent did five times or more, and some fanatic levelers (6 percent) slashed at the incomes of their richer fellows ten times or more. But the game didn't just bring out spitefulness. Perhaps even more amazingly, a majority of players (71 percent) also paid, with no expectation of gain, to increase the incomes of other participants at least once. More generous players (33 percent) did so five times or more, and some saints (10 percent) boosted other players' earnings ten times or more. The researchers note, "Most (71 percent) negative tokens were given to above-average earners in each group, whereas most (62 percent) positive tokens were targeted at below-average earners in each group."
Also, players who earned ten monetary units more than the group average received a mean of nearly 9 negative tokens. In contrast, players who earned at least ten monetary units less than the group average received a mean of only 1.6 negative tokens. The opposite was the case for those earning ten monetary units or less. They received 11 more positive tokens on average while those earning more than ten units received a mean of only 4 positive tokens. Finally, the researchers report, "On average, the bottom earner in each group spent 96 percent more on negative tokens than the top earner and the top earner spent 77 percent more on positive tokens than the bottom earner." In other words, the poor spent a good bit of their meager incomes on reducing the incomes of the rich while the rich kindly reduced their wealth to endow the poor with more resources. Interestingly, the study does not report any gender differences in behavior.
Assuming that these research findings are valid, how did this innate drive toward enforcing income equality come about? It's hard to see how an inborn drive could arise in Pleistocene hunter gatherers such that people spend their scarce resources to reduce other people's resources promotes either individual or group survival. Or is enforcing equality really all that different an activity from punishing non-cooperating cheaters? Perhaps early in human evolution, large differences in income actually correlated with cheating and thus automatically merited punishment. Another puzzle is if humans are instinctively egalitarian, how did early hierarchical civilizations in which the incomes of priests and kings were significantly higher than those of peasants come about at all? Finally, finding that humans have an innate tendency toward enforcing a norm of income equality would explain the persistent attraction of communism, progressive tax rates, the demand for universal government-supplied health care, minimum wage laws and other such destructive modern leveling ideologies and policies.
Ronald Bailey is Reason's science correspondent. His book Liberation Biology: The Scientific and Moral Case for the Biotech Revolution is now available from Prometheus Books.