Young children will pay to watch a puppet being beaten, but only 6 year olds pay more to watch punishment inflicted on a puppet that personally offended them.

Young children will pay to watch a puppet being beaten. But only 6 year olds pay more to watch punishment inflicted on a puppet that personally offended them. According to scientists trying to figure out when our sense of fairness first develops.

In a study published in Nature Human Behavior, 72 children aged four to six individually interacted with puppets in a miniature theater. One of the puppets gave the child a toy, while the other offered the toy and then withheld it. Next, a third puppet appeared onstage with a large stick and proceeded to beat whichever puppet was still onstage.

Children of 4-6 paid to continue watching punishment. But only 6 year olds paid more to watch the mean puppet get punished. Also, only 6 year olds had more frequent smiles rather than frowns when they watched the mean puppet get punished.

The good news is that people of all ages seemed to be sad when the good puppet was being punished — and, to be fair to the younger kids, it’s possible they didn’t fully understand what was going on, as opposed to truly desiring vengeance on good puppets. In the grand scheme of things, 6 is fairly young to develop a sense of justice. Just be careful around the younger kids.