Your baby's flinch when his sister screams feels alarming, and you want a clear answer about whether it harms him. A startled reaction is usually a normal reflex, not a sign of lasting damage, but ...

This story is from The Pulse, a weekly health and science podcast. Subscribe on Apple Podcasts, Spotify or wherever you get your podcasts. Sometimes, I wish I had a sign on my chair, as if I were a ...