As humans we perfectly know the feeling. We see someone else yawning and immediately after we feel the urge to yawn as well. Even if we didn’t necessarily felt that tired before. It can’t be coincidence, right?
The purpose of yawning seems to be that when doing so, their is more blood circulation to our head, therefore providing oxygen and a cooling down of our head, a good way to be more alert. But a new research* with lions shows there might be an additional function.
The researchers noticed that lions that copied the contagious yawning, also copied other following behaviours, such as moving away. They putted forward the thesis that this might be a method of increasing vigilance in the group, of promoting collective awareness for threats or food opportunities. So the yawning may serve as a real group behaviour, where different individuals become more alert to other stimuli and act towards those. An interesting find for further research!
*Casetta et al. (2021). Yawn contagion promotes motor synchrony in wild lions, Panthera Leo. Animal Behaviour 174, 149-159.
Animal Behaviour Facts 