Some Chimps Skip Food Tray If the Price Is Friendship

Free food apparently has its limits for chimpanzees. A new study of chimps at Uganda's Ngamba Island Sanctuary found they were less likely to swipe fruit from close companions than from more casual groupmates, suggesting that friendship can override food temptation. Researchers tracked 800 hours of video to map out which chimps were tight, the New York Times reports, then put pairs in a setup where one could yank a tray of pineapple away from the other.

When the thieves faced a friend, they chose to steal less often—61% of the time versus 70% with nonfriends—and sometimes refused to play along at all. Betrayals sparked loud protests and anxiety, but pals were also quicker to reconcile later. Scientists say the behavior points to basic social expectations that may underlie fairness and morality in humans. Oded Ritov of the University of California, Berkeley, a co-author of the study, pointed out there's a risk to attempting to see the emotions and behaviors of humans reflected in other species, per Popular Science, though there are indications that animals form what look to be friendships.