Can chimpanzees, apes and bonobos remember friends they have not seen for decades? A Johns Hopkins University surprising study in 2023 found that chimpanzees and bonobos can recognize former groupmates after more than 25 years apart, revealing remarkable social memories that may be surprisingly similar to those of humans. The team worked with chimpanzees and bonobos at Edinburgh Zoo in Scotland, Planckendael Zoo in Belgium, and Kumamoto Sanctuary in Japan.