Why are Yawns Contagious?

My wife has been off caffeine for the last couple weeks as a self-experiment. She is yawning a heck of a lot more. I am talking multiple times a minute. That means I am yawning a heck of a lot more as well. But why is that? I am not more tired than usual and, unlike my wife who likes to live life on the edge, I am drinking my delicious coffee every morning. But as she yawns, my yawn frequency goes up. This may be because humans mimic one another, or maybe I am doing it in solidarity with her caffeine-free situation. Turns out that yawns are a lot more exciting than they appear to be. <a href="https://medium.com/aha-science/why-are-yawns-contagious-f3ea45bf11f4">Website</a>