“[After the assessment] I was surprised to learn that most of [the infantile reflexes] were still present and uninhibited in me at the age of almost thirty in spite of having learned to compensate for and cover them up. One which was still present was an infantile reflex that babies have to assist them in passing out of the womb! It was also found that I had different infantile reflexes present in different quarters of my body and that some were partially inhibited and some not at all” (Donna Williams)
Motor development progresses from primitive reflexes to using voluntary movements.
Infantile reflexes (aka primitive, infant, or newborn reflexes) are automatic muscle reactions in response to particular stimuli. They start as early as the 25th week of gestation, and are fully present at birth in typically developing infants. Some reflexes are of a survival value (e.g., the rooting reflex helps infant find the mother’s nipple), others help infants to develop posture, alignment of head with body and voluntary motor skills.
With the development of the frontal lobes (during the first year of life), the cortical inhibition emerges and many infant reflexes become integrated with more mature patterns of response (e.g., postural reflexes – controlling balance and coordination) and replaced with the voluntary motor activity. However, some remain through adulthood. A reflex that is still present after the age it would have been replaced by voluntary movements (referred to as an unintegrated/ retained or persistent reflex) is a sign of an atypical development. Unintegrated primitive reflexes can disturb psychomotor development and involve difficulties in social and educational children’s life (Gieysztor et al. 2018).
Some of the infant reflexes are:
Rooting reflex (’searching reflex’) – Retention of the rooting reflex beyond 3-4 months of age may result in difficulty with solid foods, poor articulation and thumb sucking.
The Moro reflex (‘fight or flight’ reaction) – If the Moro reflex retained after 6 months of age, a child becomes hypersensitive (and over-reactive) to sensory stimuli; experiences sensory overload, poor balance, poor coordination, mood swings, anxiety, emotional and social problems/ immaturity.
Palmar Reflex (‘grasp reflex’) – If it persists after 4-6 months of age, it might indicate brain or nervous system damage. [E.g., a child may have difficulty with fine motor skills.
Asymmetrical Tonic Neck Reflex (ATNR) serves as a precursor to hand-eye coordination and is present from birth until about 3-9 months. If not integrated – poor eye tracking, difficulty crossing the visual midline, left-right confusion, and bringing object to mouth/ holding objects/ reaching for object while looking at it simultaneously.
Symmetrical tonic neck reflex (STNR) (‘crawling reflex’) – If not properly integrated (after 11 months), a child will find it difficult to sustain a good posture, experience physical fatigue, poor muscle tone, difficulty with concentration, problems with eye-hand coordination.
Spinal Galant Reflex – If it persists, it may affect a child’s posture, coordination, ability to sit still, walking and running.
The tonic labyrinthine reflex (TLR) – If retained, it can lead to poor muscle tone, tendency to walk on toes, motion sickness, poor balance and disorientation.
Teteilbaum and his team (2002, 2004) hypothesise that movement disturbances in infants can be interpreted as reflexes gone astray in autism: some reflexes persist too long in infancy, whereas others appear much later than they should. For example, the asymmetrical tonic neck reflex may persist too long in autism, whereas head-verticalisation in response to body tilt and some protective reflexes of the arms and head (when falling from sitting position forwards, backwards, or to the side without putting out their arms and dorsiflexing their head to protect it as they fall) does not appear when it should. The authors suggest that it may be a marker for a subgroup of autistic-to-be children: by studying the movements of such children in infancy, Asperger syndrome may be diagnosed as early as 6 months of age.
There can be different causes for retention of primitive reflexes, such as, for example, difficult birth, brain injury, traumas, falls, delayed or skipped crawling, head trauma, chronic ear infections and some others. Retained primitive reflexes can hinder the development and contribute to sensory processing problems, difficulties in performing motor skills, learning difficulties, ADHD, autism and some other conditions. The persistence of primitive reflexes alters the developmental trajectory of future motor ability and therefore their evaluation might be an early indicator of atypical development (Chinello et al. 2018; Nagai et al. 2020).
Some autistic adults with autism have described their problems caused by still present reflexes that should have been inhibited in the first weeks or months of life, e.g.:
“The neurological baggage of retained primitive reflexes and their resulting secondary motor disorders (poor posture, inflexibility, etc.) precluded my participation in society and prevented me from pursuing my interests in full…
Whatever is there in autism that is disabling, it also exaggerates personality traits, too. In other words, my core autistic traits (whether it was something positive like hyperfocus or “negative” like insistence for sameness) were made into gross stereotypes of themselves” (Tim Turner 2020).