It amazes me to see how newborn babies are so perfectly programmed for the early days of life outside the womb. Babies are born so weak and simple that they can't hold up their heads or even roll over, but they start out life with a perfect set of of reflexes designed to help them navigate early life outside the womb. All healthy babies are born with the collection of reflexes known as "primitive reflexes." Here are some of the reflexes you can expect your baby to have at birth.
A fear of falling is the only fear instinctively programmed into babies. When your baby feels like she's falling-- that is, if she loses the sensation of warmth or pressure against her chest, or is pulled in one direction and then released-- she responds by spreading and unspreading the arms, then crying.
Many evolutionary holdovers can be seen in our newborn babies. Our furry, primitive ancestors carried their babies on their backs. Like chimps, their babies clasped on to their parents' hair using their hands and feet. Human babies are, remarkably, born with a reflex that causes their toes to curl when the area under them is touched. This, known as the plantar reflex, would have helped him hold onto Mom's fur four million years ago, but is now useless.
The rooting reflex has as much utility today as it had thousands of years ago. When a newborn's cheek is touched, he will turn toward the side that was stroked and try to suckle. He may also bob his head up and down, especially when hungry, seeking a nipple. This basic reflex is necessary for a newborn's survival because it helps them to easily find and latch on to a breast.
Also important for a baby's survival and nourishment in the newborn phase, the suckling reflex enables newborns to nurse reflexively when something enters their mouths. This is the reason that even the youngest babies will suck pacifiers or bottles without "learning" to do so. Premies may have trouble coordinating sucking and breathing, but you can expect most healthy, full-term babies to have this reflex absolutely mastered.
Like the plantar reflex, the grasp reflex once served the purpose of enabling newborns hold on to their parents' bodies. Today, its primary purpose is bonding: what parent doesn't absolutely adore the feeling of a newborn's little hand wrapped sweetly around her pinkie? This reflex tends to disappear some time in the first few months-- around the time the baby stops holding her hands in a fist.
Primitive reflexes help babies survive in the world around them, even when it's still very big and new to them. It is because of these reflexes that our babies are able to make it through their first several months of life, before they're actually capable of thinking and learning on a more mature level. If you have any questions about your baby's newborn reflexes, talk to your pediatrician. The National Institutes of Health offers more information about reflexes in infancy.