Journal of Child Neurology

It's the body getting ready to go underwater, and it works whether or not there's water involved.

According to a 2012 study in the Journal of Child Neurology, researchers could set this off in almost every baby they tested just by blowing air across their face, and it worked best when the baby was already crying.

As we get older, that reflex weakens, but in a baby, it's on a hair trigger, which is why parents use it.

You blow on your baby's face to stop hiccups, you blow on your baby's face because she's screaming in the car seat and it's the only thing that resets her.