Common Primitive Reflexes and How They Affect Your Child

Understanding which reflexes are retained—and how they show up in everyday behavior—can be a game changer for identifying the root of developmental challenges. Here are some of the most common ones to look out for:

👉 Moro Reflex (Startle Reflex)

What it is: An automatic response to sudden stimuli, like loud noises or changes in position.

Should integrate by: 4–6 months old

If retained, you might see:

• Hypersensitivity to sound, light, or touch

• Exaggerated startle responses

• Poor impulse control

• Emotional outbursts or anxiety

• Trouble transitioning between tasks or environments

🧠 Why it matters: A retained Moro reflex keeps the nervous system in a heightened state of alert, making it hard for the child to feel calm and focused.

👉 ATNR (Asymmetrical Tonic Neck Reflex)

What it is: When the baby turns their head, the arm and leg on the same side extend while the opposite side bends.

Should integrate by: 6 months

If retained, you might see:

• Difficulty crossing the midline (e.g., reading across a page)

• Trouble with handwriting or copying from the board

• Awkward posture while sitting at a desk

• Poor coordination in sports or PE

🧠 Why it matters: This reflex interferes with bilateral coordination, essential for reading, writing, and many physical tasks.

👉 STNR (Symmetrical Tonic Neck Reflex)

What it is: Head movement controls arm and leg positions (e.g., head down = arms bend, legs straighten).

Should integrate by: 9–11 months

If retained, you might see:

• Poor posture at a desk

• "W-sitting" or slumping

• Difficulty learning to swim or ride a bike

• Trouble with reading and copying from the board

🧠 Why it matters: This reflex affects postural control and eye tracking, both vital for classroom success.

👉 TLR (Tonic Labyrinthine Reflex)

What it is: Influences muscle tone based on head position (e.g., head back = body stiffens).

Should integrate by: 3–4 months

If retained, you might see:

• Poor balance or frequent falling

• Difficulty with stairs or uneven surfaces

• Fear of heights or movement

• Motion sickness

• Weak muscle tone or fatigue

🧠 Why it matters: A retained TLR can interfere with balance, coordination, and spatial orientation.

Why We Can’t "Talk Away" These Issues

Primitive reflexes are automatic, brainstem-level movements. If they’re retained, it means that part of the nervous system hasn't matured the way it should. This isn’t something kids can "grow out of" or "try harder" to overcome.

💡 That’s why interventions need to involve the body, not just the mind.

The right kind of physical and sensory input—especially movement patterns that mimic early developmental milestones—can help the brain rewire and move past these reflexes, often resulting in noticeable changes in behavior, coordination, and learning.

The Takeaway

If your child has delays or struggles that don’t seem to respond to traditional strategies, don’t lose hope. Retained reflexes and an underdeveloped vestibular system are often-overlooked factors that can be effectively addressed with the right intervention.

By supporting the body’s foundational systems, we help unlock the brain’s full potential—creating a path toward smoother movement, stronger learning, and a calmer, more confident child.