Understanding Primitive Reflexes: Part 1
At SENSE-ational Spaces, we believe that every child deserves the opportunity to thrive in an environment that supports their sensory and developmental needs. One crucial aspect of early development is the presence and integration of primitive reflexes. These automatic movements are vital for survival in infancy and lay the groundwork for more complex motor skills and cognitive functions as a child grows. However, when these reflexes persist beyond their typical integration period, they can impact a child's development in various ways!
What Are Primitive Reflexes?
Primitive reflexes are innate, involuntary movements that emerge in utero and are essential for a newborn's survival and early development. Some reflexes are needed during labor, while others facilitate early motor development. These reflexes typically diminish as the child grows and higher brain functions mature. However, if they remain active beyond infancy, they can interfere with motor coordination, balance, learning, and behavior.
A Note on Reflex Observation
The descriptions below provide a helpful overview of what retained reflexes may look like in daily life. However, it's important to understand that many of these signs can also stem from other developmental factors. Just because a child shows one or more of these characteristics does not necessarily mean a reflex is retained. For that reason, screening for primitive reflexes should always be done by a trained professional, such as an occupational therapist or developmental specialist.
Commonly Retained Primitive Reflexes and Their Impact
Moro Reflex
Often referred to as the startle reflex, the Moro reflex is an involuntary response that emerges in utero and is triggered by a sudden loss of support, a shift in head position, or loud, unexpected sounds. When activated, infants typically respond with a dramatic movement: arms fling outward, then quickly retract toward the body, often followed by crying. This reflex is a protective mechanism designed to alert caregivers to potential danger.
The Moro reflex typically integrates by around 4–6 months of age.
(Harrington & Hill, 2023)
What this may look like:
Heightened anxiety or exaggerated startle responses
Sensory sensitivities, especially to noise, light, or touch
Emotional dysregulation (difficulty calming after being upset)
Poor adaptability to change or transitions
Fight-or-flight overreactions, even to minor stimuli
Sleep disturbances due to a hyper-alert nervous system
Palmar Grasp Reflex
The Palmar Grasp Reflex is an automatic response present at birth that causes a baby to tightly close their fingers around any object placed in the palm, often strong enough to support their own body weight for a brief moment! This reflex is one of the earliest signs of motor system activation and plays an essential role in early bonding and tactile awareness.
This reflex typically integrates by 4–6 months of age, as voluntary grasping and hand control begin to take over.
(Harrington & Hill, 2023)
What this may look like:
Messy or awkward handwriting due to an overly tight grip on writing tools
Difficulty with precise hand movements like buttoning, using scissors, or tying shoelaces
Fatigue or frustration during writing or fine motor tasks
Poor hand-eye coordination
Avoidance of fine motor activities, leading to delayed skill acquisition
Asymmetrical Tonic Neck Reflex (ATNR)
Often called the “fencing reflex”, the ATNR is triggered when an infant turns their head to one side. In response, the arm and leg on the face side extend, while the limbs on the skull side flex. This reflex emerges around birth and typically integrates by 6 months of age.
The ATNR plays a role in early visual-motor development, helping infants learn how to track objects and begin hand-eye coordination.
(Harrington & Hill, 2023)
What this may look like:
Difficulty crossing the midline, such as bringing the right hand across the body to the left side (important for reading, writing, and sports)
Poor handwriting or writing posture, especially when turning the head causes the writing hand to extend involuntarily
Discoordination between both sides of the body, impacting tasks like catching a ball, riding a bike, or dressing
Visual tracking issues, which can interfere with reading fluency and attention
Postural instability; children may fidget or use excessive body movement to compensate
Symmetrical Tonic Neck Reflex (STNR)
The Symmetrical Tonic Neck Reflex (STNR) typically emerges around 6 to 9 months of age and usually integrates by around 11 months. It plays a key role in helping infants transition from lying on their stomachs to crawling by coordinating head and limb movements.
The STNR is triggered by head movement in the sagittal plane:
When the head is bent forward (chin toward chest), the arms bend (flex) and the legs straighten (extend).
When the head is lifted backward (neck extended), the arms straighten (extend) and the legs bend (flex).
This reflex helps develop muscle tone for crawling and prepares the child for upright postures like sitting and walking by coordinating upper and lower body movements.
(Harrington & Hill, 2023)
What this may look like:
Difficulty sitting still and maintaining an upright posture, often resulting in a “slumping” or “W-sitting” position
Trouble with hand-eye coordination and crossing the midline, making tasks like reading, writing, and copying from a board more difficult
Poor coordination between the upper and lower body, which can lead to clumsiness or awkward movements
Difficulty transitioning between positions, such as moving from crawling to walking
Increased fatigue during activities requiring sustained sitting or focused attention
Tonic Labyrinthine Reflex (TLR)
The Tonic Labyrinthine Reflex (TLR) is a primitive reflex that helps newborns develop muscle tone and balance by responding to the position of the head relative to gravity. It emerges before birth and typically integrates by around 3.5 years of age as the child gains better control over posture and movement.
The TLR has two main responses based on head position:
When the head tilts forward (chin to chest), the body responds with flexion - arms and legs curl inward
When the head tilts backward (head extension), the body responds with extension - arms and legs straighten and arch backward
(Harrington & Hill, 2023)
What this may look like:
Poor balance and coordination, especially during activities that require stability and body control
Difficulty with spatial awareness and sensing where the body is in space
Postural issues, such as slouching or a stiff, “robotic” posture
Toe walking or overly tight muscles in the legs
Motion sensitivity or fear of movement, which can limit participation in physical activities
Spinal Galant Reflex
The Spinal Galant Reflex is a primitive reflex present from birth, typically integrating by around 6 months of age. It is triggered by stroking or tapping along one side of the infant’s lower back, near the spine.
When activated, the infant’s hips will move or “wiggle” toward the side that is stroked. This reflex assists with birthing by encouraging the baby to move through the birth canal and also plays a role in developing core stability and pelvic control.
(Harrington & Hill, 2023)
What this may look like:
Excessive restlessness or fidgeting, especially when sitting for extended periods
Difficulty sitting still, often seen in children who frequently wiggle or shift in their seats
Poor posture and challenges with maintaining an upright seated position
Sensory sensitivities or discomfort around the waistline, such as sensitivity to clothing tags, waistbands, or tight clothing
In some cases, it is linked to bedwetting beyond the typical age
The Importance of Reflex Integration
The integration of primitive reflexes is crucial for the development of higher-level skills. When these reflexes are not integrated, they can interfere with the neurological organization of the brain, leading to challenges in areas such as coordination, balance, sensory processing, attention, and academic performance. Retained reflexes have been linked to challenges such as ADHD, sensory processing difficulties, learning disabilities, and delays in fine and gross motor skills
Supporting Reflex Integration at SENSE-ational Spaces
At SENSEational Spaces, we are committed to providing resources and strategies to support the integration of primitive reflexes. Through our educational blogs and workshops, we offer insights into the role of these reflexes in early development and practical approaches to facilitate their integration.
For example, incorporating activities that promote bilateral coordination, balance, and sensory processing can aid in the integration of retained reflexes. Simple exercises, such as crawling, rolling, and activities that involve crossing the midline, can be beneficial. Additionally, creating an environment that supports sensory exploration and provides opportunities for movement can enhance the integration process.
Coming up in Understanding Primitive Reflexes: Part 2, we’ll explore practical activities and strategies to support reflex integration. Don’t miss it!
References
Harrington, R., & Hill, J. (Hosts). (2023, December 27). #288 - Primitive reflexes: The basics - Our free webinar [Audio podcast episode]. In All Things Sensory by Harkla. Harkla. https://www.podchaser.com/podcasts/all-things-sensory-by-harkla-919173/episodes/288-primitive-reflexes-the-bas-195972496
