Adult monkeys recognise photographs of their friends, according to scientists.
In an experiment, untrained Barbary macaques showed interest in the photos and spent more time scrutinising pictures of unfamiliar animals.
Juvenile monkeys were fascinated but puzzled by the photographs. They often tried to greet or touch the animal in the image.
The findings suggest that the primates learn with age to understand that photos are representations of faces.
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This reminds me of the work done with primates on theory of mind, which used mirrors to see if they would recognise themselves in the reflection or if they would think it to be another individual. Interestingly, theory of mind develops in the human brain between 3 and 4 years of age... what this article doesn't make mention of is that this might be evidence of a similar development in macaques.