Retained Primitive Reflexes and ADHD: The Piece of the Puzzle Nobody Told Me About

Going Granola Without Going Nuts · Neurodiversity · Occupational Therapy · 7 min read

I want to start with a confession. When someone first mentioned the words "retained primitive reflexes" to me, my brain immediately conjured an image of tiny little monkeys running around doing some kind of ancient ancestral dance. Like some prehistoric survival routine from a nature documentary.

Which is not exactly what it means. But also, not entirely wrong in spirit.

Once I understood that primitive reflexes are movements that are literally built into every human baby for survival, and that most of us graduate out of them in the first year of life while some kids do not quite make it all the way through graduation, it actually made complete sense. We all start with these reflexes. Most of us just do not remember having them.

What I also did not know was that my son's retained reflexes were quietly behind some things we had been scratching our heads over for years. Including his handwriting. Which at one point was, and I say this with love and a lot of retrospective humor, not something you would have trusted with a wedding invitation.

This post is for every parent who, like me, had never heard this term before. Because it might be one more piece of the puzzle for your child. And in my experience, the more pieces you have, the better equipped you are to help them. Plus this one is a little weird and interesting and I think we could all use a little weird and interesting on this journey.

First, what is a primitive reflex?

Primitive reflexes are automatic movements that babies are born with. They are controlled by the brainstem and they serve a purpose: they help newborns survive, move through the birth canal, feed, and begin developing their nervous systems. You have probably seen some of them without knowing what they were called. The way a newborn turns their head when their cheek is stroked. The way they startle and throw out their arms at a sudden loud noise. The way their little fingers grip around yours.

In typical development, these reflexes are active in the first months of life and then gradually integrate, meaning they get absorbed into the central nervous system and replaced by more voluntary, controlled movements. By the time a child is crawling, walking, and developing fine motor skills, most primitive reflexes should be fully integrated.

But sometimes they do not integrate fully. And when that happens they are called retained primitive reflexes. And that retention can show up in ways that look a lot like ADHD, sensory processing challenges, learning difficulties, and coordination problems.

What the research says

Research increasingly shows a connection between retained primitive reflexes and neurodevelopmental conditions including ADHD. A 2025 peer-reviewed study found that children with ADHD show higher rates of ATNR and Galant reflex retention compared to typically developing peers, and that retained reflexes may be linked to behavioral dysregulation, hyperactivity, and impulsivity.

A separate study published in Frontiers in Psychiatry found that disinhibition of primitive reflexes is associated with attention deficit and hyperactivity in children. And occupational therapy literature has long documented the connection between retained reflexes and challenges with handwriting, reading, focus, coordination, and sensory processing.

This does not mean retained reflexes cause ADHD, or that every child with ADHD has retained reflexes. What it means is that they can co-occur, and that addressing retained reflexes may help reduce some of the functional challenges associated with ADHD. It is one more avenue worth exploring.

What causes a reflex to be retained?

This is the part that really stopped me when I first learned about it. Retained reflexes can be linked to a number of things: birth complications, limited floor time or movement in early infancy, illness or injury in early childhood, environmental stressors, and even genetic factors.

For our son, the occupational therapist who assessed him suspected his two retained reflexes were likely connected to the fact that he was born with the umbilical cord around his neck. Even mild birth trauma, the kind that resolves quickly and leaves no lasting visible effects, can sometimes interrupt the integration process for certain reflexes. His nervous system did the best it could in that moment. And some of those early reflexes just never fully let go.

When she explained that, so much clicked into place. Not as an excuse or a label, but as a map. It helped us understand what was happening and what we could do about it.

The most common retained reflexes and what they look like.

Our son had two retained reflexes identified: the ATNR and the STNR. I had never heard of either of them. Here is a plain-language breakdown of these and the other most commonly retained reflexes so you know what to look for.

ATNR: Asymmetrical Tonic Neck Reflex

Also called the fencing reflex

In babies, when the head turns to one side, the arm and leg on that side extend while the opposite side bends. You can see this in newborns naturally. It typically integrates between four and six months.

If retained, may look like: Easily distracted, messy handwriting, poor coordination, difficulty reading and writing, poor visual tracking, losing their place easily in schoolwork, trouble with auditory listening, and difficulty crossing the midline of the body.

STNR: Symmetrical Tonic Neck Reflex

Supports crawling and postural transitions

Active around six to nine months, this reflex connects head movement to the upper and lower body. When the head goes up, the arms extend and legs bend. When the head drops, the arms bend and legs extend. This is what supports crawling.

If retained, may look like: Poor posture, tendency to slump when sitting, sitting in a W position, poor balance, poor eye-hand coordination, difficulty shifting focus from the board to the desk, slowness with copying tasks, reading and writing challenges, messy eating, and difficulty with social cues.

Moro Reflex

The startle reflex

The earliest reflex to form, present from the second trimester. When a baby experiences a sudden change in sensory input, sound, movement, touch, the arms fling out and the baby startles. It is the foundation of the fight or flight response.

If retained, may look like: A nervous system in a constant state of alertness. Emotional reactivity, sensory overload, poor stress tolerance, hypersensitivity to sound, light, or touch, anxiety, and difficulty regulating after being startled or surprised. This one in particular can look a lot like anxiety or sensory processing disorder.

TLR: Tonic Labyrinthine Reflex

Helps develop head and posture control

Present from birth, this reflex is connected to the vestibular system and helps babies develop head control and posture. It should integrate in the first few years of life.

If retained, may look like: Low muscle tone, difficulty sitting upright, toe walking, poor balance, motion sickness, and difficulty with spatial awareness.

Spinal Galant Reflex

The hip rotation reflex

When the skin along the side of a baby's spine is stroked, the hip on that side swings toward the stimulus. It helps babies during the birthing process and typically integrates by three to nine months.

If retained, may look like: Fidgeting and inability to sit still, especially if clothing or chair backs touch the spine. Bedwetting beyond the typical age. Hypersensitivity to touch around the waist or back. Poor concentration and short-term memory.

Retained reflexes are frequently seen in children with ADHD, sensory processing differences, learning difficulties, and developmental delays. They are not a diagnosis on their own. But they can be a missing piece that explains why certain challenges are persisting despite other interventions.

How we discovered it: the preschool screening.

Our son was actually screened for retained reflexes at his preschool by an occupational therapist. This was really the very beginning of us noticing that something might be a bit different about how he was moving through the world. We had not yet put any formal labels on anything. We just knew there were some things worth paying attention to.

The screening was simple, non-invasive, and observational. The OT watched how he moved, how he held his body, how he responded to certain prompts. And she identified two retained reflexes: the ATNR and the STNR. Both of which, she explained, were consistent with what she was seeing in his sensory responses and his motor patterns.

She connected them to his birth history and explained that mild birth complications, even ones that seem to resolve immediately, can sometimes leave an imprint on the nervous system's early wiring. It did not feel like blame or a diagnosis. It felt like information. And information, in our experience, is always better than not knowing.

What we did: occupational therapy.

We decided to pursue occupational therapy. And I want to be honest about our experience because I think honesty is more useful than a perfectly tidy success story.

Our son absolutely loved it. Every single week. He looked forward to those sessions in a way that he did not look forward to most things that involved any kind of work or effort. The OT was warm and skilled and genuinely good with him. Each session started the same way: they would make a list together of the activities they were going to do, how they would do them, and in what order. Then they would go do them.

The activities ranged from big body play and climbing to fine motor work, handwriting, and balance challenges. It was always purposeful and always disguised as fun. And that structure, the making of the list at the start of each session, was itself a form of executive functioning practice that carried over into how he approached other tasks.

Did it make a dramatic difference in his retained reflexes specifically? Honestly, I am not sure. It is hard to measure. What I can tell you is that I never regretted trying it. And I know I would have regretted not trying it after it had been recommended. That is enough for me.

It was a cost. It was a commitment. And it was worth it for the fact that it gave him a space where his body was understood, where effort was framed as play, and where someone saw him and worked with him without any sense that something needed to be fixed.

My honest take

Occupational therapy is not a cure and I would not present it as one. For some families it makes a significant measurable difference. For others, like ours, the benefits are real but harder to quantify. What I do know is that the process of understanding retained reflexes gave us language and context for things we had been observing but could not explain.

And that matters. Because when you understand what is happening in your child's nervous system, you stop interpreting their behavior as willful and start interpreting it as neurological. That shift in perspective changes everything about how you show up for them.

How to find out if your child has retained reflexes.

The best starting point is a referral to a pediatric occupational therapist who is trained in primitive reflex assessment. Not all OTs specialize in this area so it is worth asking specifically when you call. You can ask your child's pediatrician for a referral, or contact your school district's special education department since OT services are sometimes available through the school as part of a child's evaluation or IEP.

Some signs that might make it worth exploring: poor handwriting that does not improve with practice, difficulty sitting still especially if touch around the back or waist seems to trigger fidgeting, persistent bedwetting, significant sensitivity to sound, light, or touch, poor coordination that seems out of proportion to everything else about your child, or a general sense that their body is working against them even when their mind is trying hard.

None of these signs confirm retained reflexes on their own. But if several of them resonate, it is worth asking the question.

There is also growing research suggesting that structured movement programs, things like rhythmic exercise, balance work, and coordination-based activities, can help support reflex integration even outside of formal OT. A 2025 study found that a twelve-week structured exercise program reduced ATNR retention and improved fine motor coordination in children with ADHD, with significant behavioral improvements as well. You do not necessarily need a formal program to start incorporating more of this kind of movement into your child's daily life.

The handwriting chapter. A love story with a happy ending.

I want to talk specifically about handwriting because it was one of the most visible places we saw our son's retained reflexes show up in daily life. And because the ending of this particular story is one of my favorites.

Both the ATNR and STNR reflexes directly affect the neck, the arms, and the ability to cross the midline of the body. Crossing the midline means being able to use one hand comfortably on the opposite side of the body, which is something handwriting requires constantly. When those reflexes are not fully integrated, the physical act of writing can be genuinely hard in ways that have nothing to do with effort or intelligence.

Our son's handwriting was a struggle. It was effortful. It was inconsistent. Copying shapes was hard. Drawing was frustrating. And for a while we wondered whether something more specific was going on, whether he might have dysgraphia, which is a learning difference that directly impairs the ability to write and is distinct from just having messy handwriting.

Thankfully, after evaluation, dysgraphia was ruled out. What we were dealing with was a nervous system still working through the integration process, combined with a school environment that leaned heavily on technology and did not give his hands nearly enough practice with pencil and paper. Which, it turns out, matters enormously.

Here is where the story gets good.

Our son is now at a school that uses pencil and paper ninety-nine percent of the time. Minimal technology. Lots of writing. And his handwriting today is genuinely lovely. He has even learned to write in cursive, which he is proud of in a way that is wonderful to watch.

I could write an entire post, and probably will, about the science behind handwriting and cursive specifically and why it is so beneficial for kids with learning differences and brains that work differently. The research on cursive and how it helps get thoughts from the brain onto the page is genuinely fascinating, especially for kids who struggle with the physical act of writing. But I will save that for another day.

For now I will just say this: if your child's handwriting is a struggle, it is worth asking whether retained reflexes might be a contributing factor. And it is worth knowing that the brain is remarkably capable of continuing to develop and integrate with the right environment and the right support. My son's handwriting journey is proof of that.

And I want to say something here that might be a little countercultural in a world where we are quick to look for the diagnosis behind every struggle: sometimes it really does come down to old-school practice. Not instead of understanding the underlying cause. But alongside it.

Our son needed a lot of practice writing. He needed teachers who held him accountable for doing his best work and who did not accept illegible assignments as the finished product. Not harshly. Not unkindly. But firmly. With high expectations delivered in a warm and supportive way.

The best way I can describe his teachers this year is this: imagine a grandma who loves you so completely and so deeply, but she is still absolutely going to make sure you do the right thing. That combination of unconditional warmth and genuine accountability has been, by far, the most impactful thing we have experienced at his school this year. More than any specific intervention or program. Just love with a backbone.

So if you are in the thick of handwriting struggles with your child, yes, look into retained reflexes. Yes, consider an OT evaluation. Yes, ask about dysgraphia if the struggle is significant and persistent. But also do not underestimate what consistent practice, high expectations, and the right teacher can do. Sometimes the brain just needs more time and more repetition in the right environment. And sometimes that is enough.

Dysgraphia is a specific learning difference that directly impairs the ability to write and is worth evaluating separately if handwriting struggles are significant and persistent. Messy handwriting alone does not equal dysgraphia. But if writing is causing real distress and nothing seems to help, it is worth a proper evaluation to understand what is actually going on.

One more piece of the puzzle.

This is how I think about retained primitive reflexes in the context of everything else we navigate with our son. Not as a diagnosis. Not as the explanation for everything. Just as one more piece of the puzzle.

We are raising kids whose nervous systems work differently. Whose brains process the world at a different pace and through a different filter. And sometimes, underneath all of that, there are also these very early, very foundational wiring patterns that never quite finished integrating the way they were supposed to. Because of birth. Because of the unpredictable nature of early development. Because sometimes the body just does things its own way on its own timeline.

And you know what? That is okay. It is figurable-out-able. It is not the end of anything. It is just information.

I also want to say this, because I mean it sincerely: this journey does not have to be as heavy as it sometimes feels. There is real hard stuff in it, absolutely. The meetings and the evaluations and the advocating and the googling at 10PM and the worrying. All of that is real. But there is also so much that is funny and surprising and genuinely wonderful if you give yourself permission to see it that way.

My son went from handwriting that required a decoder ring to writing in cursive. He went from an OT session where he made a to-do list before swinging on a rope to a kid who now makes his own lists before tackling hard things. The weird little monkey reflexes that were quietly making his life harder are integrating, slowly and surely, because we found them and we did something about them.

That is a good story. And we get to be in it.

Trust the weird thing. Look into it. You might find another piece that finally makes something click. And if nothing else, you will have an excellent story to tell about the time you learned that your child had a retained fencing reflex. Which, I promise, sounds much more alarming than it actually is.

I am not a doctor, occupational therapist, or medical professional. Everything here is based on our own family's experience and information I have gathered from research and professionals along the way. If you are concerned about your child's development, please consult a licensed occupational therapist or your child's pediatrician. They are the right people to assess and guide this.

More posts in this space that might help connect the dots.

What Is a Psychoeducational Evaluation and How Do You Get One?

The 7 Types of ADHD: What I Didn't Know and Why It Changed How I Parent

Emotional Regulation and ADHD: How to Help Your Child Name Big Feelings Before They Take Over