Primitive reflexes and primitive reflex integration

About Primitive Reflexes

Primitive Reflexes are the automatic movement patterns babies are born with to respond to specific sensory stimulation. The primitive reflexes are developed in utero and are controlled by the lowest level of the brain: the spinal cord and the brain stem.

It is thought that the primitive reflexes serve three functions:

  1. Baby’s active participation in the birth process
  2. Hardwiring skills essential for survival such as breathing, sucking and swallowing
  3. Provide movement patterns as precursor for later voluntary movements and postural reflexes

Primitive reflex integration should happen within the first year of life indicating development of cerebellum, midbrain and cortex, allowing the baby to control their movements in gravity voluntarily and through postural reflexes.

Delay in primitive reflex integration indicates slower brain myelination and maturation, and may be associated with learning delays, emotional challenges and coordination difficulties.

Assessing primitive reflexes and primitive reflex integration are an important part of the Switched-on Kids programs.


Below is a description of some of the more common primitive reflexes and the possible challenges a child can suffer if the primitive reflex integration doesn’t happen well:

Fear Paralysis is an intra-uterine withdrawal reflex, which is supposed to integrate in the womb. If it does not, some authors have found it may cause an unsettled and highly strung baby, and anxiety, emotional lability and aggression in an older child

When a baby is surprised or scared, for example by a sudden movement or a loud noise, she will startle: extend neck and arms and breathe in, followed by flexing of spine and limbs and a loud cry. It is thought this reflex will help the baby take her first breath when she is first born and is a way to alert parents for help.

This is a fight-flight reflex during which stress hormones are released causing increased heart rate, breathing rate and blood pressure. This primitive reflex integration starts within the first few months of life and become the less severe reaction we as adults know as startle.

Problems with MORO integration may result in a child who is over-reactive, easily distracted, have poor attention and could even be labelled ADHD. This child may be prone to illness and may be hypersensitive to foods and airborne allergens due to frequent exposure to stress hormones.

In a baby, head rotation reflexively causes ipsilateral limb extension and abduction.  This reflex is thought to assist in the birth process, and helps the baby see his hand, so he can develop hand/eye coordination and depth perception.

If the Asymmetrical Tonic Neck Reflex does not integrate properly the child could be uncoordinated and unbalanced with crawling (if any) and walking, may have difficulty using both sides of the body at the same time as well as having problems bringing arms to midline (catching balls). Pencil grip, writing and reading could be a challenge.

In a baby, when you place your finger in his palm, the fingers will close and hold on. This reflex goes back in evolution to when babies clung on to their mother for safety.

Delayed primitive reflex integration may result in the child having difficulties with hand and finger control, pencil grip, handwriting and hypersensitivity of the hand. Due to this reflex’s association with the Rooting and Sucking Reflex, this child may often also dribble profusely and suffer delayed speech and articulation.

Stroking a baby’s cheek and lips will result in a reflex turn of the head, opening of the mouth with the tongue extended searching for the nipple and when found sucking and swallowing.

If this reflex does not integrate well, the child may be hypersensitive on the skin around the mouth, challenges with chewing and swallowing solid foods, as well as possibly causing speech and articulation difficulties. They could dribble profusely, suck their thumb, and, due to the association with the Palmar Reflex, have difficulties with manual dexterity and hypersensitivity of the hands.

In a baby, when you stroke the lumbar paraspinal muscles on one side, you will see a slight contraction of those muscles. It is thought this reflex may help the baby ‘wriggle’ during the birth process. Bilateral stimulation is involved in micturition.

Primitive reflex integration difficulties may result in a child who has trouble sitting still, ‘ants in the pants’, coordination problems, bedwetting and possibly scoliosis.

This reflex is about where the head and body are in space and the interaction with the senses. It causes the limbs to bend when the neck is flexed, and to straighten when the neck is extended.

If the primitive reflex integrate doesn’t happen properly the child may suffer disturbance in the vestibular system and its interaction with the other senses. The child may have low tone, be delayed in reaching their gross motor milestones, and may appear stiff, unbalanced, uncoordinated and clumsy. The child can suffer vision and hearing problems and may suffer motion sickness. Toe walking can be a sign of retention of this reflex.

This is not a true primitive reflex as it emerges after birth. It is the rocking motion on hands and knees just before the child learns to crawl.

Cervical flexion will cause the arms to flex, hips extend and the eyes to focus close. This causes the child to rock forward. When the neck extends, the arms will extend and the hips will flex, causing the child to rock back and train the eyes on the far distance.