Why is yawning contagious?

Yawning is an involuntary action that everyone does. It’s also been noticed that yawning seems contagious. However, new research suggests rather than being a precursor to sleep, the purpose of yawning is to cool the brain so it operates more efficiently and keeps you awake. The theory could explain a puzzling question about subconscious human behaviour – why many of us yawn when we see or hear another person doing it, or even read about it or even just think about it? The brain cooling theory says that when we contagiously yawn we are participating in an ancient, hardwired ritual that evolved to help groups stay alert and detect danger. Read more …