science

Hold on to your heart: A new study found that apes — our closest living relatives — can recognize family members and long lost friends even after decades of separation.

Researchers tested 26 captive chimpanzees and bonobos from zoos around the world, showing them pictures of former groupmates alongside pictures of unknown apes, ultimately confirming what primatologists have long suspected.

"It was a really simple test: Do they look longer at their previous groupmate, or are they looking longer at the stranger?" Laura Simone Lewis, a postdoctoral fellow in Berkeley's psychology department and lead author of the study, explained.

"And we found that, yes, they are looking significantly longer at the pictures of their previous groupmates."

There is also evidence that they became even more intent when shown a picture of an ape with whom they'd had more positive interactions, as compared with antagonistic relationships, according to the report published last week in the journal Proceedings of the National Academy of Sciences.