When “Won’t” Is Really “Can’t”: Understanding the PDA Profile

There is a kind of child — and a kind of adult — who pushes back against almost everything. Not just hard things. Even things they want to do. Even small things, like putting on shoes or sitting down to eat.

The usual words for this are defiant. Strong-willed. Controlling. But there is a growing body of research, and a lot of lived experience, pointing to something very different underneath.

What looks like “won’t” is often “can’t.” And the reason why changes everything about how you help.

I write this as a parent who lives with this every day, on both ends of it. I am not a clinician, and I won’t pretend to be. For trusted, expert information, the PDA Society is the best place to start.

What the PDA profile actually is

PDA stands for Pathological Demand Avoidance. Many people now prefer to call it a Persistent Drive for Autonomy, because that name says what is really going on.

It is understood as a profile within the autism spectrum. It was first described by British psychologist Elizabeth Newson in the 1980s, and it is recognized internationally, though it is not yet a formal standalone diagnosis in most systems.

Here is the part that matters most. The word “pathological” does not mean bad, or manipulative, or a character flaw. Researchers describe the demand avoidance as involuntary — it happens beneath conscious control. The leading way to understand it is called the autonomy-threat model. In plain terms: the nervous system reads a demand as a threat. Even a small or friendly demand. Even one the person agrees with. The body responds the way it would to danger — fight, flight, or freeze.

So the pushback is not a power play. It is a threat response. Clinicians who work with PDA adults describe people who desperately want to do the thing, and feel they cannot in the moment, because the anxiety is as strong as a phobia.

This is also what separates the PDA profile from ordinary stubbornness. Most kids resist sometimes — when they are tired, or bored, or just don’t want to. That comes and goes. The PDA pattern is deeper, more constant, and tied to a real need for control, not a passing mood.

An occupational therapist who once worked with our family shaped how we understand this. She wasn’t fond of the diagnosis itself — she found it inaccurate — and instead looked at behaviour through a sensory lens. The idea, as I came to understand it, is this: for these children the world can feel like it is in pieces and always changing, which makes it very hard to process their surroundings and organize a response. When a demand is made that they don’t have the capacity to navigate, it feels like a threat to their safety. Their intense need for control and autonomy isn’t a behavioural refusal — it is a functional necessity, a way to make sense of a world that feels overwhelming. That lens changed everything for us.

The same profile can look like night and day

Here is what I rarely see written down, and what I know from my own home.

The PDA profile does not look the same in everyone. How much it shows depends heavily on how much choice, voice, and control the person has.

I see this at both ends, because I live with both.

My son has this profile. A lot of the time, you would barely notice it — because he has choices, he has a voice, and he gets a say in what happens to him. When he feels in control, cooperation comes much more easily. That matches what the research says: when a person with this profile has freedom to make their own decisions, the sense of threat drops, and they can engage.

But he is not “fixed,” and he is not always fine. When circumstances make him feel cornered or out of control, it still comes. He has hard spin-outs in those moments. The difference is that we now understand what they are — not bad behaviour, but a nervous system that has hit its limit on pressure.

My husband has the same profile, and a much harder road. He carries adult demands my son doesn’t yet face — a demanding job, plus the weight of being a partner and a father, plus everything home life asks of him. The pressure is constant in a way it simply isn’t for a child. He is learning new tools later in life, and learning late is harder. The demands keep coming faster than the coping can catch up.

Same profile. Two very different pictures. A child who, with the right support, is mostly thriving — and an adult under heavy load who is often struggling. The biggest variable between them is how much control they have over what is being asked of them. And because my husband’s end is the harder one, it is through him that I see the demand avoidance most clearly — the daily, grinding version that my son, with the right support, mostly gets to avoid.

It taught me something I hold onto: when you see resistance, you are usually seeing a person at their limit. The kind thing — and often the effective thing — is to return some control and help with the pressure of the moment.

Why pushing harder backfires

When a child resists, the common advice is to hold firm. Don’t give in. Use rewards and consequences. Reward charts. Firm boundaries.

For this profile, research and experience agree that this usually makes things worse. More pressure means more threat. More threat means a bigger fight-flight-freeze response. People with PDA are often misread as having Oppositional Defiant Disorder and handled with confrontation — which raises the anxiety that caused the avoidance in the first place. You end up in a loop.

There is also a quieter cost. Children with this profile often feel deep shame about not being able to do what is asked, even when they truly want to. Punishment adds to that shame. It does not build the thing they actually need, which is trust and a sense of safety.

This is why the kind of support matters so much.

Our son sees an occupational therapist, not a behaviour interventionist. That choice has mattered. Instead of training him to comply, she helps him understand himself — to notice what his body is feeling, to learn to speak up for what he needs, and to hear affirming messages about who he is. The approaches that work best, across the research, are the ones that lower anxiety and offer choice: options instead of orders, collaboration instead of commands, flexibility instead of rigid rules.

For us, that approach is the difference between a home with frequent meltdowns and a home with far fewer.

What this might mean for you

I won’t tell you what to do. Every person with this profile is different, and I am not the expert. But here is what has helped our family, and what lines up with what the specialists say:

• We treat resistance as information. It usually means the pressure is too high right now, not that someone is being bad.
• We offer real choices wherever we can. Control isn’t a reward to be earned. For this profile, it is a need.
• We choose support that is affirming — that helps the person understand and advocate for themselves, rather than just obey.
• When we need real guidance, we go to trusted sources like the PDA Society, not to whoever is loudest online.

If you have a child or a partner whose resistance has been called defiance, I hope this gives you another way to see it. Underneath the “no” there is very often a nervous system asking for the one thing that helps most: a little more control over their own world.

That isn’t defiance. It is a need. And when we meet it, both the kids and the adults living with this can do so much more than just get through the day.

I’m Kelly. I don’t write this as an outsider — this is my family’s life. I share it as a parent, not a clinician. The sensory-lens perspective here is thanks to occupational therapist Jennifer Sexton. For trusted information about the PDA profile, please visit the PDA Society.