Why children like to share

We are taught to believe that Darwinian “survival of the fittest” has rewarded selfish behavior. Recent scientific studies, however, paint a much different picture. Nature has rewarded cooperation–which is why older small children like to share:

In recent years the tide has swung dramatically against such a bleak view of human nature, however. Researchers are increasingly coming to understand that people are also “programmed” to care about others. A recent contribution to this theme comes from neuroscientist Ernst Fehr at the University of Zurich and colleagues. In a study, the researchers explored a particular type of unselfishness known as inequality aversion. Suppose individual A has $10, and individual B has a lesser amount, say $5. We say individual A is inequality averse if he shares some of his cash with individual B, thus reducing the inequality between them. We say individual B is inequality averse if he is willing to sacrifice some part of his money, provided individual A’s endowment is reduced to an even greater degree, so that, once again, the inequality between the two is reduced.

Fehr and colleagues show that, in a sample of 229 children between the ages of three and eight years, younger subjects overwhelmingly conform to selfish (self-regarding) preferences. They don’t like to share and aren’t interest in reducing inequality. In contrast, the vast majority of the older subjects are inequality averse when put in either the advantageous (individual A) or inadvantageous (individual B) position.

Moreover, the researchers find that the older children are “rational” in the sense that they are more willing to share when the cost of doing so is low than when the cost is high. Finally, the children tend to be more inequality averse in dealing with “ingroup” members, or children from their own school or day care. This preference for sharing with ingroup members occurred even the sharing game was purely anonymous, so no child could determine the identity of the other players.

. . .

Although it’s now generally recognized that children are inequality averse, one experimental difficulty has been separating out strategic behavior, such as reputation building, from true preferences for sharing. In other words, I may share with you because in the future, you may reciprocate, or I may punish you at personal cost because the next time, you will be more careful to give me my “fair share.” These are purely strategic behaviors that can be attributed to perfectly selfish individuals.

The Fehr study differs from prior studies of inequality aversion in children by scrupulously preventing such an interpretation. They made all behaviors anonymous so children could never identify their partners, and therefore could not sacrifice in hopes of gaining in the future. This strategy contrasts with previous studies, which either watched children at play or analyzed teacher-pupil interactions. Although these studies found consistent pro-social behavior—the children demonstrated a willingness to share—they could not ascertain whether it was calculated selfishness or true other-regarding behavior.

It is instructive to compare and contrast human behavior regarding others with that of our nearest biological relative, the chimpanzee. My assessment of the literature is that female chimps, at least, reveal a high level of kin altruism (fathers exhibit virtually none).” Chimps of both sexes also demonstrate a fair amount of reciprocal altruism, as in mutual grooming and coalition formation, and show considerable concern for the plight of other chimps. On the other hand, chimpanzees show virtually no real inequality aversion, in the sense that they do not share with non-kin except as a means of not being pestered by beggars, and do not sacrifice to reduce their personal disadvantage. In this sense, inequality aversion seems to be a rather human innovation.

Read it all here.

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