Yawning is just your body's way of taking in more oxygen, right? Wrong. Scientists have never been able to prove the long-believed myth that the wide-mouthed, eye-squinting inhalation aids respiratory function. And it's not a way of signaling you're bored either. Spontaneous or contagious, yawning may simply be about your brain needing to turn on its internal air conditioner (similar to how sweat is triggered when your body needs to cool down).
Previous studies have shown that brain temperature can fluctuate due to sleep cycles and stress levels, but new evidence published in Physiology & Behavior shows that yawning may also be influenced by the seasons—or more specifically, ambient temperatures. Researchers monitored the yawns of 120 pedestrians between 1 p.m. and 3 p.m. during the winter and summer in two different locations (Tuscon, AZ and Vienna, Austria) to measure how ambient temperature variation affected yawning frequency.
They found that when it was too cold or too hot, people tended to yawn less frequently. They also found that the optimal temp for people to yawn was around 68 degrees Fahrenheit (a.k.a. room temperature). The closer to 98.6 degrees, which is the average body temperature, the less often people yawned because the warm air isn't cool enough to effectively regulate body temps, explains study co-author psychologist Andrew Gallup of SUNY College at Oneonta.
What does this mean to you? Not much beyond debunking some old myths about breathing and (yaaawn) boredom, and getting to know how your body operates just a little better. Let us know what you think of this weird news in the comments below or tweet us @Shape_Magazine!