Archaic reflexes in adults: can you keep them, and what signs to look for

Two very different phenomena hide behind the same word

Hello to you, the movement professional,

About two in three young high-level footballers. That is the proportion of players who, in a study published in 2024, showed at least one residual archaic reflex on testing, most often at a low level. Players of around 17, trained in high-level structures, with the kind of support many clubs envy. This figure puts to rest a stubborn idea, the one that reserves residual reflexes for children struggling at school.

So yes, an adult can keep archaic reflexes active, even at the highest level. You just need to separate them from release signs, which reappear after damage to the frontal cortex and are a matter for the physician. For the RNP reading, a residual reflex indicates which sense has not finished its wiring, and it says nothing more than that.

A residual archaic reflex is a newborn reflex that still shows up in the older child or the adult when its triggering stimulus is presented, instead of being held in reserve by the cortex. The complete map, with the ages and functions of each reflex, is in the guide to archaic reflexes. Here we stay with the adult.

Can you still have archaic reflexes in adulthood?

Yes, and more often than you would think. The study we mentioned comes from Frontiers in Sports and Active Living and covers 69 young high-level French footballers, aged about 17. The detail deserves a closer look: alongside those two players in three with at least one residual reflex, nearly one in four showed an ATNR, the asymmetrical tonic neck reflex.

Picture these players in training. Sharp changes of support, head swiveling to pick up information, a pass on the run. Nothing, to the eye, gives anything away. They perform with this reflex, by working around it. In the high-performing adult, a residual reflex behaves like a resource locked by compensation. As a result, the way you talk about it to your athlete changes: you open a lead to explore, with nothing alarming in your voice.

One trap remains, and it is a serious one. In adults, the term "archaic reflex" covers two realities that have almost nothing in common. Mixing them up can be costly.

Release signs and residual reflexes: what is the difference in adults?

Let's start with release signs. In an adult whose frontal cortex has been damaged, or sometimes with age, infant reflexes resurface. The hand closes on its own around an object brushing the palm (grasp). The lips pucker when you tap around the mouth. The chin contracts when you scratch the palm (palmomental). The big toe lifts when you stimulate the sole of the foot (Babinski sign). All of this belongs to a medical examination, and to a physician only. If you observe one with no known explanation, you refer the person to their doctor, with no comment and no protocol.

Some of these signs, the palmomental first among them, are found in a not insignificant share of healthy older adults. In isolation, they say little, and that is precisely why their interpretation falls to the physician, who places them within a full examination.

Functional residual reflexes, for their part, are identified in healthy adults through standardized field tests. You present a precise stimulus, a head rotation, a neck flexion, a light touch on the back, a backward tilt, and you watch whether an automatic response disturbs the posture or the movement. These fall within the movement professional's field, because they inform you about a sensory input and about the sensorimotor loop it feeds.

The boundary fits in one line. The release sign goes to the physician; what stays on your side is the functional residual reflex, the one you read.

Which archaic reflexes can be identified in adults, and with which tests?

In the field, most protocols derive from the work of Sally Goddard Blythe and the INPP (Institute for Neuro-Physiological Psychology). The principle does not vary from one reflex to another: you isolate the triggering stimulus, then observe what moves in the rest of the body. The meaning of a reflex is read in that trigger, even when the response involves the whole body.

You will notice that a column is missing, and that is deliberate: there is no automatic link between a response on the test and a specific difficulty in the person's life. The test shows that an old response still shows up when a stimulus is presented. What it costs day to day calls for a different reading. And before going that far, you have to ask whether you can even trust what the test displays.

Are field tests for archaic reflexes reliable?

We are touching the weak link of the subject, so let's say it frankly. Tests of the Goddard Blythe or INPP type rely on scoring by the observer, often on a scale from 0 to 4. The published data on their reliability, between two raters or from one session to another, are scarce and cover small samples. A 1 out of 4 scored on a tired day can very well become 0 the next day.

Run the experiment in your head. First version: you rotate your athlete's head in a hurry at the end of the session, they are still out of breath, the gym music is pounding. Second version: same time, same instruction to the word, same rotation speed, feet on the same floor markers, a video from the front. Only the second gives you information you can use.

That is why the RNP grid revolves around the test, stimulation, retest cycle. A single test is a blurry photo. A series of retests under identical conditions ends up making a measurement.

Non-integrated archaic reflexes in adults: what signs in training?

To the naked eye, in the adult, the residual reflex is rarely visible. You guess it in the compensations, the strategies the system has built to work around an automatic response that gets in its way. They work, often very well, and they almost always cost something somewhere.

Take a residual ATNR in a thrower or a racket-sport player. Every time the head turns to follow the ball or the target, the opposite arm receives a parasitic instruction. So the system learns to lock the neck, to freeze the shoulders, or to turn the whole trunk instead of the head alone. What you see: a stiff movement, a gaze that tracks with the chest, a posture that freezes at exactly the moment it should stay free. What the athlete tells you: tension in the upper back after technical sessions, and a fatigue they can't explain.

The price can also be paid in attention. A Moro that is still active maintains a background state of alert. Startling at the slightest sharp noise, shoulders rising as soon as the situation becomes unpredictable, difficulty releasing vigilance. Your athlete spends part of their mental availability containing a response their cortex should have held in reserve long ago.

On learning difficulties, be careful. Observational studies report more retained reflexes in children with attention or reading difficulties. That is a correlation. Nobody has shown that the reflex was the cause, or that working on the reflex would make these difficulties disappear. As long as this distinction stays blurry for you, the risk of overpromising is real.

How does the RNP reading interpret a residual reflex in adults?

For the RNP reading, a residual reflex is an indicator of the sense that has not finished its wiring. The ATNR points to the head input, cervical and vestibular, and its coupling with vision. With the Galant, we look at the tactile input of the back. The TLR refers to the vestibular system and the reference to gravity. The reflex shows where to look.

Here we find the image of the body in the dark. One zone of the sensory map stays poorly lit, and the system feels its way along, leaning on its compensations. The job is to read where it is dark, to switch that input back on with targeted stimulation, then to make this new lighting hold in the movement. For cervical proprioception, for example, this goes through precise, graded head movements, retested right away.

Integration of the reflex comes afterward, as a consequence; the cortical mechanism behind that word is detailed in the article inhibiting or integrating an archaic reflex. And if you want to see how floor patterns, crawling and all fours, are read again in adults, primal movement in adults extends the reflection.

The limits of reading reflexes in adults

No data allow us to claim that a residual reflex on its own explains a drop in performance, a discomfort or a learning difficulty. And as long as field tests remain so poorly documented, nothing guarantees that a reflex testing positive one day will still do so the following week.

The RNP reading, on the other hand, leads to a prediction that can be proven wrong. If the reflex does point to the sensory input, targeted work on that input should change the standardized retest faster than a generic integration exercise applied without prior reading. If filmed, blind-scored retests do not show this gap, the reading will have to be revised.

A residual reflex in an adult is read like an address, that of the sense still to be wired.

👉 I want to learn to read what the reflex reveals, in each person I work with.

Frequently asked questions about archaic reflexes in adults

Can you still have archaic reflexes in adulthood?

Yes. Field tests identify residual reflexes in healthy adults, elite athletes included: a 2024 study found at least one in about two in three young high-level footballers. In the high-performing adult, this reflex is most often worked around by compensations.

What are the signs of a non-integrated archaic reflex in adults?

They show up mainly in the compensations: neck or shoulders freezing when the head turns, frequent startles, fragile balance when the head changes position, restless sitting. Only a standardized, retested test can link these signals to a specific reflex.

What is the difference between a release sign and a residual reflex?

A release sign, such as forced grasp or the Babinski, reappears in the adult after damage to the frontal cortex or with age, and is a matter for a physician. A functional residual reflex is identified in the healthy adult by a field test and informs about a sensory input.

Are archaic reflex tests in adults reliable?

Their reliability is poorly documented and depends heavily on how they are administered. Standardizing the instruction, the time of day and the speed of the movement, then filming, makes the measurement usable, especially when you track its change through retests.

Does a residual reflex explain learning difficulties in adults?

Co-occurrences exist between retained reflexes and learning disorders, mostly studied in children, but no causal relationship has been demonstrated. The reflex remains one indicator among others, never an explanation on its own.

Is reading an adult's residual reflexes a form of care?

No. LabO RNP is neither medical nor paramedical, and is an addition to a care pathway, never a replacement for it.

By the LabO RNP team