(YaleNews) Children as young as age 4 express dislike of and are willing to punish those who freeload off the work of other group members, a new Yale University study has found.

But kids also make a clear distinction between those who freeload intentionally and those who have good reasons why they can’t contribute.

This expectation of cooperation emerges by pre-school and maybe even earlier,” said Yarrow Dunham, assistant professor of psychology and senior author of the paper published in Psychological Science.