Unit of Ethology, Department of Biology, University of Pisa, 56126, Pisa, Italy.
CNRS, EthoS (Ethologie Animale et Humaine)-U.M.R 6552, Université de Rennes, Université de Normandie, 35000, Rennes, France.
Sci Rep. 2024 Jan 7;14(1):361. doi: 10.1038/s41598-023-49797-5.
Yawning is undeniably contagious and hard to resist. Interestingly, in our species, even the mere sound of a yawn can trigger this contagious response, especially when the yawner is someone familiar. Together with humans, one other mammal species is known to produce loud and distinct vocalisations while yawning, Theropithecus gelada. Geladas are known for their complex social interactions and rich vocal communication, making them intriguing subjects for studying yawning behaviour. To explore the contagious effect of yawn sounds on geladas, we conducted playback experiments in a zoo-housed colony with animals living in two groups. We exposed them to yawn sounds (Test) or affiliative grunts (Control) produced by males from either their own group or the other one. The results were remarkable, as simply hearing yawn sounds led to yawn contagion in geladas, with multiple responses observed when the yawns came from members of their own group. This finding adds a significant contribution to the research on mimicry and behavioural contagion in primates. Moreover, it raises intriguing questions about the involvement of sensory modalities beyond visual perception in these phenomena.
打哈欠无疑具有传染性，而且很难抗拒。有趣的是，在我们人类中，即使只是听到哈欠的声音也能引发这种传染性反应，尤其是当打哈欠的人是熟悉的人时。除了人类，还有一种哺乳动物也会在打哈欠时发出响亮而独特的声音，那就是山魈。山魈以其复杂的社会互动和丰富的声音交流而闻名，这使它们成为研究打哈欠行为的有趣对象。为了探索打哈欠声音对山魈的传染性影响，我们在一个动物园饲养的群体中进行了播放实验，实验对象是生活在两个群体中的动物。我们让它们听来自自己群体或另一个群体的雄性发出的打哈欠声（测试）或亲和咕噜声（对照）。结果非常显著，因为山魈只需听到打哈欠的声音就会引发打哈欠的传染，当打哈欠的声音来自自己群体的成员时，会观察到多次反应。这一发现为灵长类动物中的模仿和行为传染研究做出了重要贡献。此外，它还提出了一些有趣的问题，涉及到除视觉感知以外的感觉模式在这些现象中的参与。
