Chimpanzees can 'catch' yawns from a human-like robot

Embargoed until: Publicly released: 2025-06-06 01:00

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Photo by Alex Kraft on Unsplash

Yawning is contagious in many mammals - when we see someone yawn, we find ourselves yawning too. International researchers have found chimpanzees can also 'catch' yawns from a human-like robot. The researchers showed 14 chimpanzees a robot that can make human facial expressions, including yawning and gaping, and observed that the chimps responded in kind. They say eight of the chimpanzees yawned in response to the robot yawning, and the chimps even lay down in response to the yawn, with some gathering bedding for a rest. The researchers say this is likely the first study showing contagious yawning in response to a robot, and it could mean chimpanzees see yawning as a cue to have a rest.

Media release

From: Springer Nature

Zoology: Chimpanzees can catch yawns from androids

Chimpanzees (Pan troglodytes) can ‘catch’ yawns from an android imitating human facial expressions, finds research published in Scientific Reports. The study demonstrates that chimpanzees will both yawn and lie down in response to yawns made by an android, suggesting that it may act as a cue to rest rather than simply triggering an automatic response.

Contagious yawning — where seeing another animal yawn triggers a yawn response in an individual — is primarily observed in mammals and some fish. While the evolutionary origins of yawning and yawn contagion are still unknown, some animals, including humans, can catch yawns from other species.

Ramiro Joly-Mascheroni, Beatriz Calvo-Merino, and colleagues used an android head that could simulate facial expressions to test the responses of 14 adult chimpanzees aged between 10 and 33 years. The head contained 33 rotational motors which functioned as muscles to generate facial expressions — including yawns — with each facial movement lasting 10 seconds. Each chimpanzee was exposed to four 15-minute sessions of the android demonstrating ‘yawning’, ‘gaping’, and ‘neutral’ facial expressions. These sessions were recorded on camera and each chimpanzee was scored for their responsiveness, along with the amount of time they spent lying down. Eight of the 14 chimpanzees (57.1%) displayed contagious yawning in response to the android’s ‘yawn’, while the same number also lay down in response, with some gathering bedding before lying down.

These findings appear to show contagious yawning due to an inanimate model for the first time, according to the authors. They add that the mechanisms behind this response remain unclear, and future research could explore whether other actions performed by robots are contagious to animals.