Have you even heard the term reflexes and wondered what are primitive reflexes? One of the many things that your newborn’s pediatrician will check periodically is their primitive reflexes. The existence of reflexes can be a great marker for neurological health in people of all ages, as they are controlled by the nervous system – the brain, spinal cord, and nerves. Primitive reflexes develop in the womb and are integral to an infant’s survival and future development. Below we will break down each of these reflexes and their purpose.
Related: Books About Primitive Reflexes
What are Primitive Reflexes?
As infants develop into toddlers, these reflexes should do what health care professionals call “integration”. The response that comes with the primitive reflex should integrate into a more mature or voluntary movement. If they are still present long after they should have integrated, the child will display certain characteristics specific to the retained reflex, many of which hold back their development and academic skills.
Let’s begin with the most easily noticeable reflex that babies have: the palmar reflex. This is also known as the grasping reflex. You will see this when you place your finger into the palm of an infant’s hand, and they hold on tight. This is an adorable response that can make you feel pretty special, but it is involuntary up until about 6 months of age when the reflex should disappear.
The palmar reflex is important for the development of purposeful grasping, something that an infant is learning throughout their first year of life.
Fun Fact: if your baby is holding your hair in a death grip because of this reflex, stroke the back of their hand with your finger – it should initiate a release of the grasp.
The rooting reflex is one of the main “survival” reflexes. The rooting reflex can be elicited by stroking an infant’s cheek with your finger, or more likely, a bottle or breast nipple. This is because when the cheek is stimulated, the infant will turn his or her head towards that stimulation.
If you ever need your baby to pay attention to their feeding, try giving their cheek a little stroke or tap so they turn towards the feeding source. This response should be seen in infants up until about 4 months of age.
Similar to the rooting reflex, the sucking reflex is necessary for an infant’s feeding abilities. To stimulate the sucking response, touch the roof of the infant’s mouth and they will automatically begin sucking.
Most infants learn this skill very quickly (they do get tons of practice, after all!) and the reflex will disappear by about 2 months old.
This reflex is the first of three on this list that is a response to a change in body position. Also known as the startle reflex, the Moro reflex can be seen by gently dipping a baby’s head and neck backward, as if they are falling. It can also be elicited by other stimuli like a startling noise or a drastic change in temperature.
The response that you will see in the baby is that of fear – their arms, legs, and head will reach out and then tuck back in – jerking their body back and forth. They may also open and close their hands and may even cry. The movement that is created by a startling stimulus is to protect your baby and allow them to move away from the stimuli even before they can control their own movements. Pretty cool, huh?
You may notice the startle reflex really kicking in around 1 month old. If your baby is inconsolable and moving around their body in this way, securing supporting their bottom and their head should help them realize that they are safe. By six months old, or as early as two months, this reflex will disappear.
TONIC LABYRINTHINE REFLEX
The tonic labyrinthine reflex (TLR) is used for head and postural control. We know that baby has poor control of their head and neck when they are born, and this reflex is part of what helps them gain control over this part of their body.
The TLR can be seen when moving the head and neck forward and backward. When the head moves forward toward the chest, the arms and legs bend and the baby assumes the fetal position. When the head moves back away from the chest, the arms and legs straighten. You can see this really well during tummy time!
The TLR will disappear by about 4 months old so that more advanced reflexes and movements can begin development.
ASYMMETRICAL TONIC NECK REFLEX
Last on the list of movement-based reflexes is the asymmetrical tonic neck reflex (ATNR). As the name suggests, this reflex has to do with the neck. You can see the reflex if you turn a baby’s head to one side while they are laying on their backs. They will reflexively straighten their arm and leg on the side that they are looking, and bend the arm and leg of the other side. That is where the asymmetrical part comes in: their left side and right side of their body are opposite. They look a bit like an archer, about to shoot an arrow.
This reflex is important in the birthing process, as the motions of the head can control the movement of the rest of the body help the baby through the birth canal. It is also important to the initiation of crawling, as the arms and legs move as a baby turns their heads while on their belly. For this same reason, the ATNR is crucial to the development of hand-eye coordination.
The ATNR disappears around the time an infant is gearing up for crawling, around 6 months old.
MORE ON PRIMITIVE REFLEXES
There are a few more infant reflexes that we did not mention, and you can check them out if you are looking to learn more! The Spinal Galant Reflex, the Babinski Reflex, the Landau Reflex, and the Symmetrical Tonic Neck Reflex (STNR) are some that we missed in this article. The Landau and the STNR are actually not primitive reflexes, as they develop after the baby is born, but they are developmentally important nonetheless!
Sydney Thorson, OTR/L, is a new occupational therapist working in school-based therapy. Her
background is in Human Development and Family Studies, and she is passionate about
providing individualized and meaningful treatment for each child and their family. Sydney is also
a children’s author and illustrator and is always working on new and exciting projects.