From a National Institutes of Health (NIH) press release:
Imitation Promotes Social Bonding in Primates
Capuchin Monkeys Predisposed Toward Individuals Who Imitate Them
Imitation, the old saying goes, is the sincerest form of flattery. It also appears to be an ancient interpersonal mechanism that promotes social bonding and, presumably, sets the stage for relative strangers to coalesce into groups of friends, according to a study by a team of scientists at the National Institutes of Health and two Italian research institutions.
The study authors found that capuchin monkeys preferred the company of researchers who imitated them to that of researchers who did not imitate them. The monkeys not only spent more time with their imitators, but also preferred to engage in a simple task with them even when provided with the option of performing the same task with a non-imitator.
Read the full press release