Why Do We Yawn?
Researchers are starting to unravel the mystery surrounding one of the most common behaviors: the yawn. WSJ's Jonathan Rockoff and evolutionary psychologist Dr. Andrew Gallup explain reasons behind the yawn on Lunch Break with Tanya Rivero. Photo: Getty Images.
This transcript has been automatically generated and may not be 100% accurate.
... I ... the bad every time you feeling on coming on especially ... if you happen to the enemy and you're worried what is stopping on fast well ... new research suggests that you just may be keeping your brain sharp that that might seem to race beyond social stigma heated tell us more is doubly SJ reporter Jonathan Rockoff ... thank you so much for being with us so ... then it turns out the ons may actually just be keeping our brains quarrel is that right yes to one of the leading theories about yawning is that it's the kind of cranial airconditioner ... that it is a time when the when in times of stress in times of anxiety before I came on the set here I was yawning ... Olympic athletes Qian before their hands parachute is yawn before they jump out of an airplane so why is that well it turns out that ... scientists have found that people in these stressful anxious situations experience a slight rise in pre temperature it's hardly noticeable less than a degree ... but it's enough to impact the functioning of the brain ... and body on in your calling in these deep gulps of cooler air and helps you to cool in the brain restored to normal cognitive function makes perfect sense to me we also had added Dow up an evolutionary psychologist at the State University of New York atoning Otto with that ... so in a Gothic and then now evidence that the former we understand it ... reason three awning that we didn't have enough oxygen ... that's been debunked ... Ch ... although financial wisdom holds that Beyonce's increased to her liner to our brain ... research conducted over two decades ago has falsified ... this leads us to the hypothesis and found a link between ... different levels of oxygen and carbon taxes in the in the air and influence beyond ... this ... fella ... I ask you why he is nodding contain this there's still a mystery or ... is it perhaps to prompt some kind of behavior ... this is a good question ... and ... no one really knows why yawning is contagious although recent research has suggested that this this this association between ... contagious yawning and and in ... other words those that are better this were higher and the teenagers are hardly the only solution ... and ... however as villainous really tell us about the function of contagious yawning ... according to the crippling hypothesis that the view that Beyonce function to call the brain contagious yawning ... may have evolved to promote ... growth isn't so is increasingly on cruise cognitive functioning by lingering tensions to top two levels the spreading of the year across the group ... that enhanced overall group arousal ... alertness conditions so if it were facing again Teradata and we can all become alert together ... and fight about that seems to that seems to make sense ... now said we tried to make ourselves in awe ... well we don't even have to make or so's you know if we buy just talking about it by reading about it by thinking about it we we all year ... for most of this you ... right and and one thing that we can't use stifling the turns now ... when say on gets caught my eyes common that I love getting your article you wrote that they are more common in the summer with teens make perfect sense because where ... harder in the summer that's right ... I ... got a pen and added thanks to both of you for that