Envy emerges out of our sense of fairness, fueled by competition. It is part and parcel of a hierarchical society. When we envy someone, we have detected a difference or inequity between our own condition and that of another. We want what someone else has, presumably because we like what they have. Wanting and liking are in harmony. Recognition of the inequity fuels competition to redress the imbalance. This sense of fairness appears early in child development, changing in systematic ways as a function of a culture’s norms. The Swiss economist Ernst Fehr, who led the brain imaging studies of punishment and reward discussed in Chapter 1, assembled a team of developmental psychologists to test for evidence of fairness in young children ages 3-8 years old. Fehr was especially interested in when children recognize a disparity or inequity in the distribution of resources, and what they are willing to do, if anything, to redress the imbalance. The experimenter paired up each child with a partner of the same age who was either from the same school or a different school; the school distinction was set up to look at in-group versus out-group differences which, as discussed in chapter 1, can lead parochial altruism — the paradoxical result of greater cooperation among group members and greater hatred and violence toward those outside. Though each child knew about their partner’s age and school affiliation, they never saw their partner. Each child therefore knew only that they were playing with someone from their school or someone unfamiliar to them. Each child played three different games. In each game, the experimenter told one child to decide how to distribute a fixed amount of candy. In the prosocial game, the decider either takes one candy and gives one to the partner or takes one candy and gives nothing to the partner. If children are sensitive to inequities and want to share in order to make things fair, they should pick the 1-1 option; picking the 1-0 option doesn’t