Do you ever look at your child's IQ report and feel unsure what it's really telling you? That's a common feeling. The answer is often simpler than the report makes it look.
An IQ test is a snapshot. It captures one morning, in one room, under one set of rules. It does not capture the child you watch at the kitchen table every day.
That gap is exactly what the research has started to explain. ADHD and autistic traits don't lower a child's whole mind. They tend to pull down a couple of specific parts of the test while the thinking parts stay steady.
What the research found
A 2024 meta-analysis pulled together scores from autistic and ADHD children and adults across many studies. Autistic participants performed in the typical range for verbal and nonverbal reasoning. But they scored about one standard deviation below the mean for processing speed, with slightly reduced working memory.
The review called this a "spiky" profile. Strong reasoning. A dip in how quickly the brain handles routine tasks. That spiky shape is the thing a single IQ number can flatten out.
For ADHD, the same review found performance mostly at age-expected levels, with slightly reduced scores for working memory. In 2026, Lavigne-Cerván and colleagues looked at children aged 6 to 16 on the WISC-V. The ADHD group scored significantly lower than the control group on working memory and processing speed.
One more piece matters if your child has both. A 2026 study by Narzisi and colleagues found that children with both ASD and ADHD scored significantly lower than the ASD-only group in working memory, processing speed, and full-scale IQ. The researchers describe this combined presentation as a distinct profile, marked by compounded cognitive difficulties. In short, it deserves its own look, not a borrowed one.
The meta-analysis was careful about one point. The pattern on these tests is not sensitive or specific enough to diagnose anything on its own. It is a map of strengths and difficulties, not a verdict.
How to read the report
The number on the front page is the least useful part. The breakdown underneath is where your child actually shows up.
- Look past the total. The Full-Scale IQ is an average, and averages hide the spikes. Ask for the index and subtest breakdown so you can see where the score dipped and where it held strong.
- Find the processing speed line. If that number sits lower than the reasoning scores, that is the spiky profile the research describes. It tells you about speed, not about how smart your child is.
- Ask for plain words. Reports can read like another language. Ask the psychologist to write one short paragraph, in everyday terms, explaining what each weaker area means for daily life.
Practicing the slower skills at home
You can't drill an IQ score higher, and you shouldn't try. But you can give the slower skills easy, low-pressure practice.
- Keep instructions short. Working memory tires quickly. Give one step, let your child finish, then give the next. This takes the load off the exact skill the studies found runs a little lower.
- Let speed tasks be untimed. At home, take the clock away. When there's no race, your child can show you the thinking that a timed test never sees.
- Use a short movement break. A quick stretch or a five-minute dance before homework can help your child settle back in. It isn't exercise for its own sake. It's a reset.
What to bring to the care team
Clinicians only get the test morning. You get all the other mornings. Your observations fill in what the number leaves out.
- Bring your own notes. Jot down how your child handles puzzles, multi-step chores, or getting ready in a hurry. Hand those notes over with the report. They turn a flat score into a real picture.
- Write down what your child says. When I brought our log to her psychologist, she asked, "What did your daughter say?" I had to admit I was not tracking that. Now I write down her own words, because they explain the scores better than I can.
- Ask about accommodations. If processing speed is the barrier, extra time or a quiet room can let your child show their reasoning instead of their speed. Schools often say yes when you name the specific need.
Holding the number loosely
Here is the part I keep coming back to. The 2024 review noted that autistic individuals may especially benefit from a cognitive assessment to identify and support their strengths and difficulties. That is the right use of these tests. Not to rank a child. To find where to help.
A spiky profile isn't a broken one. A slower processing speed sits right next to strong reasoning on the same page. When you read the report that way, a confusing score turns into a plan.
So before you let one number define your child, go back and find the spikes. They are usually the most honest part of the whole report.
Have you spotted a pattern in your child's scores that didn't match the child you know? Tell me about it in the comments.
This article is for general information only. It is not medical advice and is not a substitute for care from your child's doctor or care team. I'm a parent, not a doctor.
Sources
- (2024). Cognitive Profile in Autism and ADHD: A Meta-Analysis of Performance on the WAIS-IV and WISC-V. Archives of Clinical Neuropsychology. PMID 37779387
- Lavigne-Cerván, Collado-Valero, Navarro-Soria, Rosales-Gómez, Torrecillas-Martínez (2026). ADHD, Subtypes and Cognitive Performance: WISC-V as a Support Tool for Diagnostic Assessment. Actas Españolas de Psiquiatría. PMID 42343738
- Narzisi, Barbetti, Fabbri-Destro, Berloffa, Fantozzi, Viglione (2026). Cognitive and emotional profiles in children with ASD, ADHD, and comorbid presentations: evidence for a distinct clinical phenotype. Frontiers in Psychiatry. PMID 41853080