Do All Newborn Startle?

All healthy newborn are born with an evolutionarily programmed involuntary impulse called Moro reflex. So if your baby is startled by the sound of a pot clanking or a siren, for instance, he'll fling his arms wide, spread hid fingers, then grab instinctively - for Mom, of course. Then he'll bring his arms back to his body and relax. Newborn's haven't learned to differentiate between common and uncommon noises. As you little one matures, his brain learns to distinguish sounds and movements and suppresses this primitive reflex.