Bears can exactly mimic another bear’s facial expressions, casting doubt on humans and other primates being the only mammals able to express their emotions.
Sun bears have been observed opening their mouths to match their playmates when they are interacting face-to-face.
Researchers claim that such facial mimicry has not been seen in primates outside humans and gorillas. Dogs can also use mimic each other to reinforce bonds.
In the behavioural study, they found that bears can use facial expressions to communicate with others in a similar way to humans and apes.
This ‘strongly suggests’ that other mammals could also perform this complex social skill and, in addition, have a degree of social sensitivity.
The researchers studied 22 sun bears – a solitary but also playful species in the wild, for more than two years.
In total, 21 matched the open-mouthed expressions of their playmates during face-to-face interactions.
When they were facing each other, 13 bears made expressions within one second of observing a similar expression from their playmate.