Why “Can’t vs Won’t” Thinking Fails Neurodivergent Children

One of the most persistent ideas in parenting and professional practice is this:

Some behaviours are “just typical” for a child’s age and stage — and others are because of autism, ADHD, or disability needs.

From there, a second belief often follows:

• If it’s “just behaviour” then, we hold a firm boundary and “nip it in the bud” 

• If it’s “because of need” then, we respond with support and compassion

It sounds reasonable.

But it rests on a flawed assumption:

that a child moves between two distinct states — one where they are choosing behaviour, and one where they are overwhelmed.

In reality, there is no such split.

There is one child, with one nervous system, moving through a world that places uneven, often invisible demands on them.

What we see as behaviour is not a switch between “can” and “can’t”. It is the surface expression of shifting capacity, load, and safety - moment to moment.

And this way of thinking asks us to do something that is not actually possible:

to reliably separate behaviour into neat categories of choice versus need - based only on what we can see and our biases.

The Problem With Sorting Behaviour Into Boxes

We are making high-stakes decisions about support, limits, consequences, and connection — based on interpretation, not based on access to the child’s internal state.

When we decide:

• “they’re just being manipulative”

• “they’re attention-seeking”

• “they could do better if they wanted to”

we are not observing facts.

We are assigning intent.

And often, we assign more negative intent to children who are already marginalised - disabled, neurodivergent, or struggling to meet normative expectations. This is where ableism and childism quietly shape what we see as “reasonable” behaviour.

So the question becomes:

How accurate are we, really, when we decide a child could do better?

“Kids Do Well If They Can” — And What That Actually Demands of Us

Dr. Ross Greene's well-known phrase is often quoted:

“Kids do well if they can.”

This is not just a compassionate slogan. It is a shift in how we understand human behaviour.

It asks us to move from:

• behaviour as choice

to:

• behaviour as an indication of skills, capacity, load, and environmental demands - in that moment

And crucially:

If a child is not doing well, something is getting in the way.

Not:

• they don’t want to

• they’re pushing boundaries

• they’re trying to control the situation

But:

they cannot access the skills required in that moment to meet the expectation.

The Chocolate Biscuit Question

Take a familiar moment:

A child is crying, escalating, repeatedly asking for another chocolate biscuit.

Two interpretations sit side by side:

Interpretation A:They want another biscuit. They are escalating to get their way. We must hold the boundary.

Interpretation B:They are at the edge of their regulatory capacity. The biscuit is predictable, safe, regulating. Meeting this need might prevent collapse.

The problem is:

From the outside, these two scenarios can look identical.

There is no reliable behavioural marker that tells us:

• this is manipulation

• this is dysregulation

And even if we take Interpretation A — this is manipulation — the explanation does not hold.

Because what do we mean by manipulation in a young child?

This is really about a child already under strain, using the only strategies available to them to try to change an intolerable situation.

What gets labelled as “manipulation” is often:

• distress expressed through persistence

• a need that has not yet been understood

• a nervous system trying to regain predictability or control

And crucially:

a child who had more adaptive, flexible options available would use them.

So even within Interpretation A, we arrive at the same place:

this is a child operating at the edge of their capacity.

Which means:

they cannot do any better in that moment.

What Are We Teaching in That Moment?

When we respond to distress as if it is choice or manipulation, children learn:

• My distress is not understood

• My communication is mistrusted

• My needs are dismissed

• Support is conditional on me appearing “reasonable”

• Adults will hold power over me, even when I am overwhelmed

This is not about one biscuit.

It is about relational safety.

Why the “Firm Boundary vs Compassion” Split Breaks Down

We are often told:

• sometimes be firm

• sometimes be flexible

But this assumes we can accurately judge when a child has capacity.

The reality is:

Capacity is not stable, visible, or linear - especially for neurodivergent children.

It is shaped by:

• sensory load

• transitions and uncertainty

• accumulated stress across the day

• communication processing demands

• hypervigilance, masking, and internalised effort

• relational safety (or lack of it)

So the same child, in two similar situations, may have:

• capacity in one moment

• no capacity in the next

So What Do We Do Instead?

If we cannot reliably distinguish “won’t” from “can’t”…

we need a way of responding that does not depend on making that judgement in the moment.

1. Lead With Curiosity, Not Judgement

Shift from:

• “They’re trying to get their own way”

to:

• “What might be getting in the way right now?”

Curiosity keeps the relationship open, reduces escalation, and allows a fuller picture to emerge.

2. Assume There Is a Reason — Even If You Don’t Yet Understand It

Behaviour always makes sense from within the child’s experience — from their standpoint of living and sensing the world.

If we can’t see the reason yet, that is a limit in our access, not evidence that there is no reason.

3. Reduce Load Before You Reinforce Limits

If a child is dysregulated, adding:

• demands

• explanations

• consequences

• repeated “no” or redirection

• emotional intensity in our tone

  increases load.

  
  

Instead, consider:

• fewer words

• softer tone and body language

• reducing sensory and environmental demands

• offering proximity without pressure

  
  

4. When You Need to Say No — Hold the Boundary and Soften the Landing

There are times when the answer is no.

But “no” does not need to mean:

• withdrawal of connection

• escalation of control

• moral judgement

It can look like:

• acknowledging the need

• naming the limit

• staying alongside

For example:

“You really want another biscuit. I know it matters to you. We’re not having another one right now. That’s hard. I’m here for you.”

The boundary stays.

But the child is not left alone inside it.

5. Sometimes, Flexibility Is the Support

If a child is at the edge of collapse:

meeting the need is not reinforcing behaviour - it is supporting a nervous system already under strain.

The question is not:

• What lesson does this teach?

But:

What does this child need, right now, to stay within a tolerable state?

6. Reflect Later, Not in the Moment

Understanding comes after regulation.

Later, we can explore:

• patterns

• triggers

• unmet needs

• skills not yet developed

We can also ask:

• Are the adult expectations appropriately matched to the child’s skills and context?

• Or are we asking the child to consistently meet demands that exceed their capacity?

  
  

7. Reframe “Attention-Seeking” as Connection-Seeking

If a child is seeking attention:

they are seeking connection, co-regulation, or safety.

The need is not the problem.

The question is how we meet it without shame.

A Different Kind of Confidence

This approach does not offer certainty.

It asks us to tolerate not knowing:

• Is this capacity or overwhelm?

• Should I hold or flex?

But it offers something more important:

relational accuracy over behavioural control

Because when we get it wrong — and we will —

a child who experiences us as:

• curious

• responsive

• on their side

can recover from that.

A child who experiences us as:

• misinterpreting

• controlling

• withholding

• punishing

learns something much harder to undo.

To sum it up: this is not the absence of boundaries.

It is a shift in how we understand what a child is able to meet within them.

Perhaps the question is not:

Is this behaviour choice or need?

But:

What response keeps this child safe, understood, and connected — even if I’m unsure?

Because in these moments, we are shaping:

• how children understand themselves

• how safe they feel with us

• whether they learn that support is available when things fall apart

And that matters far beyond any single moment.

Elaine McGreevy, Neurodivergent Speech and Language Therapist