Next time you’re stuck on a math problem, try yawning. According to scientists at the State University of New York, we yawn to boost blood flow and chill the brain, which in turn makes us feel more attentive.

“Brain-cooling” also explains why we “catch” a yawn. Contagious yawning could be triggered by empathic mechanisms which function to keep a group awake and raise the general attentiveness.

Paratroopers also report yawning before they jump. It signals a transition between behavioural states of wakefulness and sleepiness, and boredom to alertness (They’d better be alert before jumping out of an airplane!).

So, for future purposes try yawning in history class – you might even shift that C to an A!