Given a choice, most humans would probably rather spend time with nice people than with jerks. But the opposite seems to be true of bonobos, a recent study suggests.

“Of our two closest relatives, chimps and bonobos, [bonobos] are the ones known to show less extreme aggression,” says the study's lead author Christopher Krupenye, an evolutionary anthropologist now at the University of St. Andrews in Scotland. “So we thought, if either of them are likely to share with humans this motivation to prefer helpers, it may be bonobos.”

Krupenye and Duke University anthropologist Brian Hare tested a group of 43 bonobos living in a sanctuary in the Democratic Republic of the Congo. In one experiment, 24 bonobos watched a series of cartoons depicting an anthropomorphic circle trying to ascend a hill. The circle was either helped by a triangle or hindered by a square. The apes were then offered two identical pieces of fruit under a paper cutout of either the “helper” triangle or the “hinderer” square. Like human infants, bonobos could distinguish each shape on the basis of its social behaviors. But unlike humans, they preferred the square. The findings appeared in January in Current Biology.

Behaviors humans see as antisocial might, among bonobos, be more reflective of social dominance. And for apes living in a strict hierarchy, it pays to befriend those on top. Krupenye says his team's results support the notion that the preference to avoid individuals who mistreat others is one of the things that set humans apart from other apes. But University of Southern California developmental psychologist Henrike Moll, who was not involved in the study, argues it may not make sense to compare the two species this deeply on the basis of their reactions to these videos—especially if humans interpret them in terms of morality, whereas bonobos view them through the lens of social dominance.