Hand model of the brain: the brain behind the behaviour

Your child insists the broken cracker is the problem. It isn’t really about the cracker. By the time the cracker breaks, something in their nervous system has already sounded the alarm, and they’re reaching for whatever explanation makes sense in the moment. That doesn’t mean the distress isn’t real.

One analogy we use to make sense of what happens in the brain during a meltdown is Dr Dan Siegel’s hand model of the brain. It’s a simplified picture, but a really useful one.

How the hand model of the brain works

Make a fist with your thumb tucked inside. Each part of your hand stands for a part of the brain.

Your wrist and palm are the brainstem, the oldest part of the brain. It runs the things we never have to think about, like breathing, heart rate and body temperature, and it’s where fight, flight and freeze responses start.

Your thumb is the limbic system, the feeling brain. It sits deep in the middle of the brain and handles emotion, memory and threat detection. It includes the amygdala, a small structure that works a bit like a smoke alarm, scanning constantly for danger and sounding fast.

Your fingers are the prefrontal cortex, the thinking brain. It sits at the very front of the brain, just behind your forehead. This is the part that helps us pause, plan, problem-solve, see someone else’s point of view and calm the alarm when it goes off. It’s also the last part of the brain to fully mature, well into our twenties.

When your fingers are folded over your thumb, the thinking brain can talk to and soothe the feeling brain. Lift your fingers and you have what Siegel calls a “flipped lid”. The thinking brain becomes much harder to access, and the feeling brain and body take the lead. The thumb never leaves. It is not that the feeling brain switches on in a meltdown, it is that the thinking brain stops covering it.

This isn’t a choice, or something that happens consciously. It’s a nervous system doing its job.

The hand model of the brain, after Dr Dan Siegel. Thumb tucked away = the feeling brain. Fingers folded over = the thinking brain in charge.

One honest note. Real brains are a lot messier than a fist! There’s no actual lid, and all these parts are chatting to each other all the time. Feelings are part of how we think and make decisions, not something that gets in the way of them. But the hand model gets the experience right. When stress builds up enough, the part of us that can pause and think things through gets much harder to reach, and the fast, protective part takes over. It’s simple on purpose, and that’s what makes it so handy in the middle of a hard moment.

Why this happens more for some kids

Neurodivergent kids, including many ADHDers, often have nervous systems tuned to detect threat more readily, and executive functioning skills (planning, prioritising, sequencing, filtering information) develop at a different rate.

These skills aren’t fully mature in any human until well into their twenties, so expecting a child to “just calm down” or “think it through” in the moment isn’t developmentally realistic.

Sensory processing plays into this too. A child who is already managing background noise, scratchy clothing, or too much visual input has less capacity left over for coping with the next thing that goes wrong. Distress behaviours often build on top of an already full sensory load, not out of nowhere.

Early neuroimaging studies found that in young children, the amygdala (the brain’s threat-detection centre) can measure larger in autistic children than in their peers, a difference that tends to level out by adolescence (Schumann et al.).

Findings across the wider research field since have been mixed, and what this means for day-to-day experience isn’t yet well understood, but it’s one thread of evidence for why some nervous systems may be primed for threat detection earlier on.

A note on PDA

For kids with a PDA profile (Pathological Demand Avoidance, or Pervasive Drive for Autonomy), this threat response can be triggered by demands and expectations themselves, even ones that seem small or reasonable to everyone else.

A request to put on shoes, sit down, or stop an activity can register in the nervous system the same way an actual threat would, because autonomy and control feel essential to safety.

This means the usual approach of adding more structure, more consequences, or more firmness often backfires, since it adds pressure exactly where the nervous system is already on high alert. Reducing the sense of demand (offering choices, collaborating rather than directing, dropping non-essential asks) tends to support regulation far more than holding firm.

Ask yourself… is this a learning moment?

Before you respond, it helps to check in with one question: is your child’s lid down, or has it flipped? If their thinking brain is online, this might genuinely be a moment to teach, problem-solve, or talk something through. If their lid has flipped, it isn’t, not yet.

A flipped lid means their brain isn’t in a state to process information, take on a new idea, or reason through consequences, no matter how reasonable or well-intentioned the lesson is. Trying to teach into a flipped lid doesn’t just fail to land, it adds more threat, because you’re expecting logic from a brain that currently can’t access it.

The lesson isn’t lost. It’s just not for right now. If the answer to “is this a learning moment” is no, the job in that moment isn’t teaching, it’s helping your child find their way back to a closed fist first.

What helps in the moment

Validate first, and let that be the whole sentence. “That’s really hard” goes further than logic or reassurance. “I know this is hard, but next time you need to…” cancels out the validation, because it was never really validation, it was a lesson wearing a softer opening. Less is more here.

Don’t reason with the feeling brain. Save explanations for afterwards.

For anticipatory anxiety, gently redirect attention (I Spy, questions, curiosity) rather than talking more about the worry itself.

Curiosity helps more than correction, even if what they say doesn’t quite add up.

Co-regulate by matching their energy first, then gradually easing it down together, rather than jumping straight to calm. For some kids, especially those with a PDA profile, an adult who goes very calm or soft can feel controlling or dismissive and add to the distress rather than ease it.

What tends not to help

Reasoning, negotiating, or explaining logic while the feeling brain is in charge
Threats, bribes, or consequences delivered mid-meltdown
Time-out framed as punishment for losing control
Correcting or arguing with what they’re saying (“that’s not true,” “that doesn’t make sense”)

None of these are wrong to think of, they just tend to add another layer of threat rather than helping a child find their way back to calm.

A lot of what pushes us toward firmness in a public meltdown isn’t really about what our child needs. It’s the audience, a shopping centre, a family gathering, other parents watching, and the fear underneath it: that if we don’t respond firmly, people will judge us, or our child will think they’ve “gotten away with it.”

That fear is understandable, but responding to it doesn’t help your child regulate. It often makes things harder, because now there are two nervous systems activated instead of one, your child’s, and yours, from feeling watched and judged.

Worth remembering in the moment: no one in that shopping centre will recall this in five minutes. Your child, and how safe they felt with you in it, will.

What to say afterwards, not during

Once your child is back in their thinking brain, reflecting together supports learning: “What might help you stay in control next time?” Said during the meltdown, this activates threat further. Said afterwards, it builds capacity.

Reframing “losing control”

Rather than shame (“I am bad”, “something’s wrong with me”), the message we want kids to take is: “When I lose control, I’m safe. The people around me will help me find it again.”

That’s what actually builds regulation skills over time.

The short version

Behaviour in the moment is communication, not defiance.
Ask yourself: is this a learning moment? If the lid’s flipped, it isn’t yet.
The thinking brain goes offline under threat. Wait for it to come back before talking things through.
Validate first, reason later.
Attuning to where they’re at is doing more than it feels like in the moment.
A public meltdown can trigger our own fear of judgement. That fear is real, but it’s not a reliable guide to what your child needs.

Where this comes from

Siegel, D. J. Hand model of the brain. Dr Dan Siegel. drdansiegel.com/hand-model-of-the-brain
Schumann, C. M., Hamstra, J., Goodlin-Jones, B. L., Lotspeich, L. J., Kwon, H., Buonocore, M. H., Lammers, C. R., Reiss, A. L., & Amaral, D. G. (2004). The amygdala is enlarged in children but not adolescents with autism; the hippocampus is enlarged at all ages. Journal of Neuroscience, 24(28), 6392–6401.

This is general information, not individual advice. If meltdowns are a regular part of your family’s week and you’d like help working out what’s driving them, an occupational therapist can work through that with you.