Children aren’t affected by so called ‘yawn contagion’ until they’re around 4 years old, a report in the Public Library of Science ONE journal suggests.
The idea of ‘catching’ a yawn has been associated with a fair few myths over the years, but children simply can’t develop contagious yawning until they’ve learnt to understand another’s emotion. So, while yawning is often associated with boredom, particularly amongst children, it’s actually a reflection of the mood of another that they’ve come to recognise.
Relationships between fellow yawners is also shown to affect whether a yawn is passed on or not, with family members proving to be the most likely to share a yawn. Fewer than one in 10 yawns were passed between strangers, while half of all yawns between family members were contagious, a study of 109 adults over a one-year period demonstrated. It also takes longer to pass a yawn between strangers than it does with people you’re related to.
Professor Elisabetta Palagi, from the University of Pisa, who lead the study, notes that the association between empathy and yawning is also seen among monkeys and apes.