As children grow older, they become more selective in their helpfulness. Starting around age 3, they will share more generously with a child who was previously nice to them. Another behavior that emerges at the same age is a sense of social norms. “Most social norms are about being nice to other people,” Dr. Tomasello said in an interview, “so children learn social norms because they want to be part of the group.”

Children not only feel they should obey these rules themselves, but also that they should make others in the group do the same. Even 3-year-olds are willing to enforce social norms. If they are shown how to play a game, and a puppet then joins in with its own idea of the rules, the children will object, some of them vociferously.

Where do they get this idea of group rules, the sense of “we who do it this way”? Dr. Tomasello believes children develop what he calls “shared intentionality,” a notion of what others expect to happen and hence a sense of a group “we.” It is from this shared intentionality that children derive their sense of norms and of expecting others to obey them.

Shared intentionality, in Dr. Tomasello’s view, is close to the essence of what distinguishes people from chimpanzees. A group of human children will use all kinds of words and gestures to form goals and coordinate activities, but young chimps seem to have little interest in what may be their companions’ minds.

If children are naturally helpful and sociable, what system of child-rearing best takes advantage of this surprising propensity? Dr. Tomasello says that the approach known as inductive parenting works best because it reinforces the child’s natural propensity to cooperate with others. Inductive parenting is simply communicating with children about the effect of their actions on others and emphasizing the logic of social cooperation.

“Children are altruistic by nature,” he writes, and though they are also naturally selfish, all parents need do is try to tip the balance toward social behavior.

Image Credit... Sylvio Tuepke

The shared intentionality lies at the basis of human society, Dr. Tomasello argues. From it flow ideas of norms, of punishing those who violate the norms and of shame and guilt for punishing oneself. Shared intentionality evolved very early in the human lineage, he believes, and its probable purpose was for cooperation in gathering food. Anthropologists report that when men cooperate in hunting, they can take down large game, which single hunters generally cannot do. Chimpanzees gather to hunt colobus monkeys, but Dr. Tomasello argues this is far less of a cooperative endeavor because the participants act on an ad hoc basis and do not really share their catch.