Nobody likes a show-off. So someone with a singular skill will often hide that fact to fit in with a group. A recent study reported for the first time that this behavior begins as early as two years old.

In the study, led by a team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and published in Psychological Science, two-year-old children, chimpanzees and orangutans dropped a ball into a box divided into three sections, one of which consistently resulted in a reward (chocolate for the children; a peanut for the apes). After the participants figured out how to get the treat on the first try, they watched as untrained peers did the same activity but without any reward. Then the roles were flipped, and the participants took another turn while being watched by the others. More than half the time the children mimicked their novice peers and dropped the ball into the sections that did not produce chocolate. The apes, on the other hand, stuck to their prizewinning behaviors. The children did not simply forget the right answer—if no one watched them, they were far less likely to abandon the winning choice.

The results suggest that the human desire to conform is inborn or at least develops at a very young age. This urge to conform probably evolved to be stronger than that of our ape cousins because group harmony was extremely important in growing hominin communities dependent on the exchange of cultural information, according to the authors. “We all like others who are similar to us,” explains psychologist and lead author Daniel Haun. Conforming boosts these feelings of sameness.

Of course, conformity is not always the best choice, nor is it always the norm—plenty of people prefer to lead, not follow. Yet in the absence of all other information about a group, “following the majority is usually a very good first choice,” Haun says.