Here’s a story from the trenches.
I once worked with a little girl who, at first, seemed to have a developmental delay. She was quiet, hard to engage, slow to respond, and not using much language. I assumed that speech and language were the primary issues in her lack of engagement. But something about her didn’t quite add up. She seemed more “unavailable” than delayed, like her energy was being used somewhere else. Eventually, we learned that she had a medical condition that was causing her significant pain. Once that piece of the puzzle came into focus, everything changed. She wasn’t refusing to communicate, and she wasn’t behind; she was internally distracted by pain in a way that made speaking incredibly hard. It was one of those cases that reminded me, again, to stay humble, stay curious, and keep asking, “What else could be going on here?”
Which brings us to today’s question: what if every confusing presentation is the wrong working theory in disguise? And, can a functional child development approach “work” for these kids?
This post is about kids that the systems around them cannot quite figure out. The neurodivergent kid. The kid with a learning disability. The chronically dysregulated kid. The kid carrying something from before you knew them. These are the children whose behavior is most confusing to the adults around them, which means their behavior is the most likely to be misread, mismeasured, and treated for the wrong thing.
The Functional Child Development framework does not change for these kids. The pillars are the pillars. What changes is how you apply them. And the core principle -- that behavior is a signal, a piece of information about what a child’s system needs -- works hardest precisely where the signal is hardest to read.
Start with the signal.
When a child behaves in a way the adults around them cannot make sense of, the reflex is to treat the behavior. Escalation protocols. Behavior charts. A medication conversation. Sometimes those are right. But the FCD frame asks a prior question: what is this behavior telling us about what is happening upstream of it?
Treating a child for attention problems when they are chronically sleep-deprived. Treating oppositional behavior when the child is in physical pain they cannot describe. Treating anxiety when the child is being bullied in a setting the adults do not see. Treating a speech disorder when the child is partially deaf.
In each case the visible behavior is real. The working theory about its cause was wrong, and the wrong theory is sometimes sending everyone down a road that does not arrive anywhere useful.
The fix is not to become a better diagnostician, though that helps. The fix is to ask the upstream questions before reaching for the downstream label. To treat the behavior as a signal worth decoding rather than a problem to suppress.
The way you decode the signal is to walk through the pillars. For the complicated kid, the walk looks the same as it does for any child. The answers are where everything is different.
Connection. The question is not whether this child has a relationship with a regulating adult. The question is what this particular child’s nervous system needs from that adult, and whether anyone in their daily life is delivering it in a form the child can actually receive. For some neurodivergent children, the standard ways we show warmth -- sustained eye contact, lots of animated verbal affection -- are not regulating. They are overwhelming. The need for a secure, attuned relationship is not different for these children. It’s just that what attunement looks like from the outside can be completely different. Attunement is the work of reading this specific child, not running a script.
Regulation. Sleep, Fuel, Senses, Move, Feelings. For complicated kids, the sensory dial is the one the adults most often miss. The child who looks oppositional may be in sensory overload that no one has named (and that they don’t yet have the capacity to understand. It’s just their life). The child who cannot sit still may be managing pain or have a body that needs to move to stay organized. The child melting down at four in the afternoon may not have eaten anything since breakfast that their body needs. “Bad behavior” might read as a choice, but is often a body doing the best it can in conditions no one has adjusted.
Play and Exploration. The standard, curriculum-shaped assumptions about how children should play often misfire badly for complicated kids. The interest this child actually has is the entry point, and that interest may look unusual: the encyclopedic knowledge of trains, the obsession with how elevators work, the patterns in the bathroom tile that hold their attention completely. Those “weird interests” are not a distraction from real engagement. It is real engagement, and real engagement is precious and rare and worth building on rather than redirecting away from.
Identity and Purpose. The complicated kid often receives their identity from clinical and educational systems before they receive it from their family or can develop their own. “You are the kid with the diagnosis.” That message arrives early and lodges deep. Which means the family’s role -- telling this child a fuller story about who they are, helping them experience themselves as capable, letting them know they matter before anyone asks them to have it all figured out -- matters more for the complicated kid, not less.
Resources and Demands. The load on a family raising a complicated kid is structurally heavier. The evaluations, the specialist appointments, the medication adjustments, the IEP meetings, the insurance fights, the hours on the phone. Reducing demand is harder and more important here than anywhere. A depleted caregiver cannot do any of the above, and the caregiver of a complicated kid is running closer to depletion as a baseline condition of the work.
I want to be honest about something the framework cannot do.
For some of these children, the honest answer to “what does FCD say about my specific kid” is: not enough yet. The research on how the Connection pillar applies in autism is real but incomplete. The research on how the Regulation pillar applies to chronic-pain conditions is thinner than anyone would like. The question of what happens to identity development when a child has been receiving disability-identity messaging since age four does not have a settled answer.
FCD is not a manual for every condition, and I would not trust it if it claimed to be. FCD is a framework for thinking about a child’s development, applied through the lenses of the people who actually know the child -- the parent, the clinician, the teacher. The framework helps you ask better questions. For the complicated kid especially, better questions are often the thing that has been missing.
The complicated kid is not an exception to this framework. The same five pillars hold. The child’s profile is part of the conditions within which the framework has to work, not a defect it is trying to correct. The kids who are hardest to read are the kids who are served best by this way of thinking.
If you are parenting a complicated kid, here is the practical version.
Walk through the pillars for your specific child. Connection, Regulation, Play and Exploration, Identity and Purpose, Resources and Demands. Notice which one you keep getting stuck in. That is the entry point, and the place worth bringing to whoever helps you with your kid.
Before you add one more intervention to your child’s life, ask the upstream question. What condition might be producing this signal? Is it sleep? Is it sensory? Is it pain? Is it something social happening where you cannot see it? Is it a side effect? Is it a transition, or a loss, or a fear the child has not been able to name?
And bring this frame to your child’s clinicians. Ask them to think upstream with you. The ones who will are worth holding onto.
Try This
This week, pick one behavior your child does that confuses you. Run the pillars on it: Connection, Regulation, Play and Exploration, Identity and Purpose, Resources and Demands. Not to solve it today. Just to see whether there is an upstream condition you have been treating as background noise.
Consider This
If behavior is a signal, what signal has your child been sending that you, or the systems around your child, have been hearing as misbehavior?
If this resonated, restack it on Notes -- that’s how it reaches the next parent. If a specific person came to mind while you read, forward this email to them.
Want the research behind this post? Read the Dive Deeper: The Complicated Kid — five studies that anchor what we wrote, what they found, and where the evidence has limits.
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