Research in the Journal of the International Society for the Study of Individual Differences with a paper titled Personality and Individual Differences has come up with a theory that could indicate who's trustworthy and who would stab you in the back given half a chance...
Academics from Baylor University in Texas have tested 135 students were for Machiavellian egocentricity (those incredibly irritating selfish types), and for things such as cold-heartedness.
It's common knowledge that as soon as one person yawns, everyone else catches it.
Or NEARLY everyone, that is.
Among the people who were tested, the ones who scored most highly for unfavourable characteristics were the ones least likely to yawn.
Freaky stuff!
Brian Rundle, a PhD student involved in the study, told The Times:
'One of the biggest lines of evidence is that (contagious yawning is) very much related to empathy.
'While this is a really interesting finding, it doesn't mean that if you're not affected by a contagious yawn there's something wrong with you.'
'There's some evidence that to show that in baboons or dogs or chimps the alpha male tends to yawn first,' he added.
'If you're sitting around the campfire it cues everyone else to yawn, and instead of going to bed at separate times they all do it at same times.'
Do you think they got their inspiration from DCI John Luther?
We've been yawning all the way through writing this – phew, we're safe! What do you think the worst trait in a person is? Selfishness? Arrogance? Rudeness? Tell us on Facebook or Twitter @CloserOnline