Understanding Primary Reflexes: How They Shape Development and Impact Growth

Jan 28

What Are Primary Reflexes? Primary reflexes are automatic responses that our bodies have to certain stimuli, like touch or sound. They are essential survival mechanisms that help us interact with the world, develop, and stay safe. These reflexes are present from birth and help newborns adapt and develop skills that are necessary for survival. Though we all have them, external factors like stress, a chaotic environment, or excessive screen time can affect their development.

These reflexes are an integral part of our genetic makeup, meaning every human, regardless of their origin, has them. They bridge the gap between automatic survival behaviors (like flinching) and more controlled, learned actions (like walking or writing). Over time, primary reflexes help with emotional, social, and brain development, enabling individuals to grow and learn as they interact with the world.

For instance, an infant who experiences choking while swallowing may develop a survival instinct, leading the brainstem to send signals that restrict food intake. This can cause feeding difficulties that require therapy intervention, potentially even leading to the need for a feeding tube. In another case, an infant may touch a hot object while crawling, and the hand-grasp reflex may lock into place as a protection, hindering the development of other manual skills.

The Importance of Early Reflexes in Child Development

An important study conducted in 2019 evaluated the prevalence of retained primitive reflexes in preschool children in the Southeastern U.S. It found that many children aged 3-5 years still exhibited retained reflexes, with the Tonic Labyrinthine Reflex (TLR) being the most common. This study highlights the importance of screening for primitive reflex retention in preschool-aged children to allow for early intervention.

Below, we explore several common primary reflexes and their impact on a child's development:

Moro Reflex: The Startle Reflex

What It Is: The Moro reflex is an automatic response to sudden movements or loud noises. When triggered, the baby will extend their arms and legs out, then quickly bring them back in as though hugging themselves. This reflex is intended to protect the baby from potential danger.
When It’s Present: The Moro reflex is present from birth and helps babies react to potential threats.
When It Should Be Integrated: This reflex typically integrates by 4-6 months of age.
Consequences of Retention: If not integrated, it can lead to anxiety, emotional dysregulation, hypersensitivity to vestibular stimulation, and difficulty focusing. Older children may experience maladaptive self-protection patterns and poor immune function.

Spinal Galant Reflex: The Lower Back Reflex

What It Is: Triggered by stroking one side of the lower back, this reflex causes the baby to curve toward the stroked side. It aids in movement during birth and assists the baby’s ability to adjust to positional changes.
When It’s Present: Present from birth, it plays a role in early movement.
When It Should Be Integrated: The reflex typically integrates by 9 months.
Consequences of Retention: Retention can result in posture issues, difficulty sitting still, bedwetting, ADHD, and gross motor coordination problems.

Asymmetrical Tonic Neck Reflex (ATNR): The Fencing Reflex

What It Is: When a baby turns their head to one side, the arm on the same side straightens while the opposite arm and leg bend. It’s essential for hand-eye coordination.
When It’s Present: Present from birth and helps with early motor skills like reaching, rolling, and turning the head.
When It Should Be Integrated: Should integrate by 6 months.
Consequences of Retention: If it persists, it can cause coordination issues, learning challenges, and affect tasks like writing and sports. It may also lead to processing disorders and attention issues.

Babinski Reflex: The Foot Reflex

What It Is: The Babinski reflex occurs when the sole of the foot is stroked, causing the toes to fan out and the big toe to point upward.
When It’s Present: Present at birth, the Babinski reflex helps doctors assess the health of the nervous system.
When It Should Be Integrated: This reflex disappears by 6-12 months.
Consequences of Retention: Retaining this reflex can lead to poor balance, coordination issues, and developmental delays in motor skills and language.

Symmetrical Tonic Neck Reflex (STNR): The Crawling Reflex

What It Is: Triggered when the head tilts forward, causing the arms to bend and the legs to straighten. Tilting the head back causes the opposite response. This reflex supports the transition from crawling to sitting and standing.
When It’s Present: Appears around 6 months and helps the baby progress through early motor milestones.
When It Should Be Integrated: Should integrate by 9 months.
Consequences of Retention: If retained, it can result in difficulties with balance, coordination, and tasks such as writing. Children may also experience academic issues and social challenges.

Tonic Labyrinthine Reflex (TLR): The Head Position Reflex

What It Is: The TLR is triggered by changes in head position. When the head tilts back, the body straightens, and when the head tilts forward, the body curls.
When It’s Present: Present at birth, it helps with motor control and head movement.
When It Should Be Integrated: This reflex should integrate by 6 months.
Consequences of Retention: Retained TLR can cause poor balance, poor posture, and difficulties with coordination. It can also impact the development of gross motor skills like crawling and walking.

Palmar Grasp Reflex: The Hand Grasp Reflex

What It Is: The palmar grasp reflex causes a baby to automatically grasp anything placed in their palm.
When It’s Present: Present from birth, the palmar grasp reflex is one of the earliest reflexes to appear.
When It Should Be Integrated: The reflex typically integrates by 5-6 months of age.
Consequences of Retention: If not integrated, it may cause delayed fine motor development, hand control issues, and challenges with later milestones like writing or using utensils.

Rooting Reflex: The Feeding Reflex

What It Is: The rooting reflex helps babies find the breast or bottle for feeding. When a baby’s cheek or mouth is gently stroked, they will turn their head toward the stimulation and open their mouth.
When It’s Present: Present at birth and critical for early feeding.
When It Should Be Integrated: This reflex typically fades by 3-4 months.
Consequences of Retention: A retained rooting reflex can lead to feeding difficulties, delayed oral motor skills, and difficulty transitioning to spoon-feeding or chewing.

Landau Reflex: The Postural Reflex

What It Is: The Landau reflex helps infants develop control over their trunk and head. When the baby is held horizontally (face down), their head, neck, and trunk extend, and they typically arch their back, helping with motor control.
When It’s Present: Appears around 3-4 months of age and strengthens by 5-6 months.
When It Should Be Integrated: Integrates by 12-24 months.
Consequences of Retention: Retaining the Landau reflex can cause poor postural control, delayed gross motor development, and motor planning issues.

Conclusion: The Importance of Primary Reflexes in Development

Primary reflexes play a crucial role in a child’s development. They guide early motor skills, help with survival, and set the foundation for later learning and coordination. If these reflexes are not integrated at the right time, they can lead to a variety of developmental challenges, such as difficulties with balance, coordination, social skills, and learning.

Early detection of retained reflexes and seeking appropriate interventions can help children overcome these challenges and ensure they develop the necessary skills for a successful future. If you're concerned about your child's reflexes or development, seeking guidance from a developmental specialist or therapist can be a key step in fostering healthy growth.

Understanding and addressing these reflexes is essential for giving children the best start in life.

Written by: Dr. Marisa Milavetz

At Strive Pediatrics, we’re here to help ensure your child develops strong motor skills, coordination, and confidence. Our expert team can assess retained reflexes and provide targeted interventions to support healthy growth. Contact us today to learn more about how we can help your child reach their full potential!