The phenomenon of "contagious yawning" may not be as potent in rooms full of elderly people, research suggests.
Older people are less likely to be susceptible to "catch" a yawn from someone else, a study implies.
But age only accounts for a small amount of the variation in why some are susceptible to an infectious yawn and others are not, the US researchers said. The team of experts from the Duke Centre for Human Genome Variation said their study also dispelled the theory that contagious yawning is linked to empathy.
The study, published in the journal Public Library of Science ONE, examined 328 healthy participants who underwent a number of tests to assess their cognitive function and levels of empathy, energy and sleepiness. They then watched a three-minute video of people yawning and experts recorded how many times they yawned while watching the clip.
Some did not yawn at all while others yawned 15 times during the film - 222 yawned at least once.
The researchers did not find a strong connection between yawning and empathy or intelligence. The only factor that appeared to influence whether or not someone was susceptible to a contagious yawn was age - as age increased, participants were less likely to yawn, they said.
Study author Elizabeth Cirulli said: "Age was the most important predictor of contagious yawning, and even age was not that important."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article