Research has shown that they can remember another bonobo or chimpanzee for more than 25 years.
Researchers used infrared eye-tracking cameras to record what the primates looked at when they were shown side-by-side images of other bonobos or chimpanzees.
One photo was of a stranger, while the other was of a bonobo or chimpanzee with whom the participant had lived for a year or more at some point in their life.
They found that the monkeys' eyes lingered significantly longer on images of those they had previously lived with, suggesting some degree of recognition.
They also looked longer at monkeys with whom they had had a more positive relationship.
Researchers found that the monkeys' eyes lingered significantly longer on images of those they had previously lived with, indicating some degree of recognition
In one case, a bonobo named Louise had not seen her sister or cousin in more than 26 years, when the researchers showed her their images, her eyes focused on both of them (File Image)
The findings also support the theory that long-term memory in humans, chimpanzees and bonobos likely originated from our shared common ancestor who lived between 6 million and 9 million years ago.
In one case, a bonobo named Louise had not seen her sister or cousin in more than 26 years. When the researchers showed her their images, her eyes focused on both.
Dr. Laura Lewis, from the University of California, Berkeley, said: 'These animals richly recognize each other. We don't know exactly what that representation looks like, but we do know that it will last for years.
“This study shows us not how different we are from other monkeys, but how similar we are to them and how similar they are to us.”
Previous research has shown that dolphins can recognize each other's distinctive calls for up to twenty years. “To date, that is the longest long-term social memory ever found in a non-human animal,” says Dr. Lewis.
The findings also support the theory that the long-term memory of humans, chimpanzees and bonobos likely comes from our shared common ancestor who lived between 6 and 9 million years ago.