Young children share rewards based on merit

The study, conducted by Patricia Kanngiesser and Felix Warneken at Harvard University, showed that 3 and 5-year-olds considered both the amount of work they contributed themselves and their partner's contribution level when doling out rewards.

This sharing pattern is not infallible though; the researchers found that the children did have a self-serving bias, and few of them gave away more than half of the reward, even when their partner had worked more.

"It was long thought that young children only care about their own benefit when distributing rewards, but our findings show that they are sensitive to fairness principles like merit. Our sense of fairness thus already develops in early childhood," says Dr. Kanngiesser.