Decoding Newborn Reflexes

Many of your little one’s first movements are reflexes – meaning they’re completely out of your baby’s control. Learn more about 8 of these natural responses, and what prompts them.

Whether they’re opening their mouth when their cheek is brushed or gripping your finger after it strokes their hand, many of your little one’s first movements are reflexes – meaning they’re completely out of your baby’s control.

In other words, when the right environmental triggers happen, baby’s body responds in certain ways automatically, without any thought from baby.

Some newborn reflexes help baby get the nourishment they need, while others help their survival in different ways. And still others don’t have a clear reason behind them.

But regardless of their purpose, be sure to enjoy these reflexes while you can. Baby will grow out of them before you know it!

Learn more about 8 of these natural responses, and what environmental cues prompt them, below.

To see some of the newborn reflexes in action, and for more information, watch this video from Stephanie Phipps of the Michigan Inter-Tribal Council:

Rooting reflex

What is it?

When baby feels something brush against their cheek, lip, or side of their mouth, they turn their head towards what brushed against them, then open their mouth.

Why does it happen?

This is how babies search for your breast, or a bottle, when they’re hungry.

How long does it last?

From birth until around 4 months of age. After that, baby can find the nipple or bottle more easily, so they don’t have to search for it with rooting.

Sucking reflex

What is it?

When a breast nipple, bottle nipple, or something else (like a finger) touches the roof of baby’s mouth, they’ll close their lips and start to suck.

Why does it happen?

Again, it’s all about getting the needed nutrition.

How long does it last?

Interestingly, the sucking reflex doesn’t appear until week 32 of pregnancy, and isn’t at full strength until about 36 weeks. That’s why preemies born before 36 weeks usually have a weaker suck, and may need help with feeding.

Sucking is an automatic reflex until baby is about 3 months old. Of course, since it’s so crucial to feeding, baby will continue to suck on the breast or bottle after that. But they’ll be making a conscious choice to do so. Baby might also consciously suck a thumb or finger to soothe after 3 months.

Moro reflex (startle reflex)

What is it?

When baby hears a loud noise or sees a sudden movement, or their head position abruptly changes, baby will throw out their arms with open hands. Then, they’ll pull in their arms and legs, close their hands, and cry. Even baby’s own crying can sometimes trigger the Moro reflex. This reflex is named after Ernst Moro, the doctor who identified it.

Why does it happen?

We don’t know for sure. But this could be a “leftover” reflex from when babies had to tightly hold onto their moms. If something startled a baby and made them loosen their hold on their mother, the Moro reflex could have been a warning for the mother to quickly catch them.

How long does it last?

Around 2-4 months of age, the Moro reflex suddenly disappears.

Grasping reflexes

What are they?

The main grasping reflex (palmar grasp) happens when a finger or object touches baby’s open palm, and baby grips it tightly. This one’s very satisfying and heartwarming to trigger – gently stroke baby’s palm with one of your fingers and watch baby hold onto the finger with your hand.

A similar grasp (the plantar grasp) happens when something touches the sole of baby’s foot, and baby curls their toes to grab it.

Why do they happen?

While the palmar grasp is likely meant to help a baby bond with their parents (holding hands!), experts aren’t sure why babies have the plantar grasp.

How long do they last?

The palmar grasp usually lasts until a baby is around 5-6 months old. The plantar grasp lasts longer, until 9-12 months of age.

Tongue-thrusting reflex

What is it?

When solids enter your young baby’s mouth before they’re developmentally ready, or something else “abnormal” enters your young baby’s mouth, their tongue will thrust forward to force it out.

Why does it happen?

This protects a baby from choking on solid foods when they aren’t ready for solids yet.

How long does it last?

This reflex will vanish around 4-6 months of age. When it’s gone, that’s one key sign that your baby is ready to start solid foods. But as long as they still have the reflex, they can’t start solids yet, because the reflex will keep pushing the food out of baby’s mouth.

Stepping reflex

What is it?

This reflex is sometimes called the “walking reflex” or “dancing reflex” – for good reason. If you hold baby upright, support them under their arms, and let their feet touch a solid surface – say, the floor, a changing table, or your lap – baby will move their feet up and down, almost like they’re walking or dancing.

(Holding baby upright is perfectly safe for baby, as long as you support their head. So, feel free to have fun with this reflex. Try putting on some music, holding baby in a way that triggers the reflex, and watching baby “dance!”)

Why does it happen?

Scientists don’t know for sure, but this could happen because baby knows innately that humans are supposed to walk.

How long does it last?

Usually, for about two to three months. Then, around baby’s first birthday, baby will start to walk for real – but this time, it will be a learned behavior and not a reflexive one.

Tonic neck reflex

What is it?

While baby is on their back and their head turns to one side, they’ll straighten the arm on the side their head is facing. On the opposite side, they’ll bend the arm at the elbow. Together, this looks almost like a fencing position. But sometimes, this reflex won’t trigger if baby is distracted or crying.

Why does it happen?

This could be a protective reflex – or it could be involved in navigating the birth canal. It might also help with hand-eye coordination. But the true purpose remains a mystery.

How long does it last?

The tonic neck reflex will go away between 5 and 7 months of age.

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