![](\"https:\/\/i.dailymail.co.uk\/1s\/2023\/12\/18\/21\/79102773-12878715-Researchers_found_the_apes_eyes_lingered_significantly_longer_on-a-4_1702935558252.jpg\")
<\/p>\nA study has revealed that they can remember another bonobo or chimpanzee for more than 25 years.<\/p>\n
Researchers used infra-red eye-tracking cameras to record where the primates gazed when they were shown side-by-side images of other bonobos or chimps.<\/p>\n
One picture was of a stranger, while the other was of a bonobo or chimp the participant had lived with for a year or more at some point in their life.<\/p>\n
They found the apes’ eyes lingered significantly longer on images of those with whom they had previously lived, suggesting some degree of recognition.<\/p>\n
They also looked longer at apes with whom they’d had more positive relationships.<\/p>\n
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Researchers found the apes’ eyes lingered significantly longer on images of those with whom they had previously lived, suggesting some degree of recognition\u00a0<\/p>\n
In one case, a bonobo named Louise had not seen her sister or nephew for more than 26 years. When the researchers showed her their images, her eyes honed in on both of them.<\/p>\n
Dr Laura Lewis, from the University of California, Berkeley, said: ‘These animals have a rich recognition of each other. We don’t know exactly what that representation looks like, but we know that it lasts for years.<\/p>\n
‘This study is showing us not how different we are from other apes, but how similar we are to them and how similar they are to us.’<\/p>\n
Previous research has shown dolphins can recognise one another’s signature calls for up to 20 years. ‘Until this point, that has been the longest long-term social memory ever found in a non-human animal,’ Dr Lewis said.<\/p>\n
The findings also bolster the theory that long-term memory in humans, chimpanzees and bonobos likely comes from our shared common ancestor that lived between 6 million and 9 million years ago.<\/p>\n