Johns Hopkins University reports:

Apes recognize photos of groupmates they haven’t seen for more than 25 years and respond even more enthusiastically to pictures of their friends, a new study finds.

The work, which demonstrates the longest-lasting social memory ever documented outside of humans and underscores how human culture evolved from the common ancestors we share with apes, our closest relatives, was published today in the journal Proceedings of the National Academy of Sciences.

“Chimpanzees and bonobos recognize individuals even though they haven’t seen them for multiple decades,” said senior author Christopher Krupenye, an assistant professor at Johns Hopkins University‘s Krieger School of Arts and Sciences who studies animal cognition. “And then there’s this small but significant pattern of greater attention toward individuals with whom they had more positive relationships. It suggests that this is more than just familiarity, that they’re keeping track of aspects of the quality of these social relationships.”

Adds lead author Laura Lewis, a biological anthropologist and comparative psychologist at University of California, Berkeley: “We tend to think about great apes as quite different from ourselves but we have really seen these animals as possessing cognitive mechanisms that are very similar to our own, including memory. And I think that is what’s so exciting about this study.” [Continue reading…]