The average adult yawns about 20 times a day. But why? Surely we can’t all be that tired

This reflex occurs most often due to state change, i.e. during periods of transition between waking and sleep

Research indicates we yawn to promote alertness, or cortical arousal and sometimes due to increases in brain temperature

One hypotheses is that people yawn when other people yawn due to a phenomenon called echopraxia

Yawning is an evolved form of synchronized group behavior – out of our 20 yawns, many of them occur during shared periods of transition throughout the day

When other people yawn we also become more sensitive to our own physiological state – maybe we’re tired and we didn’t know it until someone else’s yawn gives us the trigger

If a dog or cat is socialized in the same house as you, cross-species yawning contagion can occur

Recent research suggests that the variability could signal levels of empathy or ability for empathetic processing