Almost every parent does the same thing with a new evaluation report. They flip past the history and the careful paragraphs and land on one number: the IQ score. I understand the pull. After weeks of waiting, a single figure feels like the answer you came for. It almost never is.
That number is real and it means something. But it is a summary of a summary, and the most useful information in your child's report is usually sitting in the scores underneath it, the ones most families never get walked through.
What does an IQ score actually measure?
An IQ score is an average of several different thinking skills, not one thing your child has more or less of. Most children's evaluations use the WISC-V (the Wechsler Intelligence Scale for Children, the most widely used children's IQ test), which measures five separate abilities and then blends them into a single full-scale number.
- Verbal reasoning: using words to explain, define, and reason out loud.
- Visual-spatial: working with patterns and puzzles and seeing how pieces fit together.
- Fluid reasoning: spotting the rule in a problem your child has never seen before.
- Working memory: holding information in mind long enough to use it.
- Processing speed: how fast your child takes in and acts on simple information.
The full-scale IQ is the average of those. Averaging is tidy. It is also where the detail goes to die.
Why can two children with the same IQ look nothing alike?
Because the same average can be built from completely different parts. A child who scores in the 95th percentile for verbal reasoning and the 25th for processing speed can land at the exact same full-scale number as a child who is steady-but-middling across the board. On paper they match. In a classroom they are two different kids with two different problems.
Two boys I tested a few months apart both came out at a full-scale 108. The first could talk circles around adults and came undone the moment he had to get any of it onto paper. The second barely said a word during the talking tasks, then built every block design in front of him in record time. Same number. Nothing else the same.
The full-scale IQ tells you how tall the building is on average. The index scores tell you which floors are missing.
Dr. Anna LeviWhat is "scatter," and why do I read it before the IQ?
Scatter is the spread between those index scores, and it is often the first thing I look at. When the indexes sit close together, the full-scale number is a fair summary of your child. When they are far apart, that single number averages away the exact thing the family walked in to understand.
A wide gap is not bad news by itself. It is information. It usually marks where school feels harder than it should, and it points straight at the accommodation that would actually help, like extra time for a fast thinker with slow processing speed.
How much should one or two points matter?
Less than you would think. Every IQ score carries a margin of error, because no test captures a child perfectly in a single afternoon.
The test's own manual reports a confidence range around each score, usually about five points in either direction. So a reported full-scale of 98 really means "most likely somewhere between about 93 and 103." The difference between a 98 and a 101 is statistical noise, not a real gap between two children.
Round numbers feel precise, but an IQ score is a best estimate with a range around it, not a fixed measurement like height. Treat small differences, your child's versus a sibling's or this year's versus last year's, as the noise they usually are.
What can an IQ score actually predict?
Part of how your child does in school, and not a lot beyond that. In study after study, an IQ score accounts for less than half of the differences in how children do academically, which means more than half comes down to things the test was never built to measure.
Here is some of what it leaves out: whether your child can focus, whether anxiety hijacks them on a test, how organized they are, whether they bounce back from a wrong answer, and how well they are being taught. I have evaluated gifted kids who were failing their classes and kids with thoroughly average scores who were thriving. The number predicted neither. What was happening around the number did.
How do you read a score report like a clinician?
Skip the headline number and go straight to four things. They will tell you more than the composite ever could.
Find the index scores, not just the full-scale
The composite is the average. The index scores are the actual abilities. Read those first, because that is where your child's strengths and struggles live.
Look at the spread before the size
Are the indexes bunched together or spread out? A tight cluster means the full-scale number describes your child fairly. A wide gap means it does not, and the gap is the part worth talking about.
Read the percentiles and the confidence range
A percentile tells you how your child compares with 100 other children their age. The 50th is dead average; the 90th means they did as well as or better than 90 of those 100. Each score also comes with a range, so ask for it instead of fixating on the single point.
Read the words, not only the numbers
The sentences in the report about how your child worked are gold. Did they give up fast or double-check everything? Did they talk their way through a hard problem or freeze? That is the part a number cannot hold.
When is a single IQ number actively misleading?
In a handful of common situations, the full-scale number is the wrong summary to trust. A comprehensive evaluation exists partly to catch them.
- Twice-exceptional kids: a child who is gifted and also has ADHD or a learning difference. The second pulls the average down and hides the first.
- A child still learning English tested in English on the verbal tasks, where the score reflects language exposure more than reasoning.
- A rough day: anxiety, a cold, or a hard morning can quietly depress a score.
- One slow index dragging the rest: when processing speed or working memory is low but reasoning is strong, the full-scale undersells the child. This is why reports often include a GAI (the General Ability Index, a version of the score that leans on reasoning and sets speed and memory aside).
Every private evaluation in our practice is run by two clinicians. A single number is easy to accept at face value. A profile with real scatter needs two people asking why the gap is there and whether the composite should even be reported as a summary. The subtle profiles, the ones common in girls and in twice-exceptional kids, are exactly the ones a second set of eyes catches.
If you are holding a report full of numbers and no one has walked you through what they mean, that conversation is worth having. You can book a consult with our team, and we will read the profile with you, not just the headline.
Questions parents ask us most
Is a higher IQ always better?
Not in any way that helps you parent. A higher number does not predict happiness, friendships, or even grades on its own. What helps is knowing your child's specific strengths and gaps, which is what the rest of the report is for.
The school only gave us the full-scale score. Can I see more?
Yes, ask for it. You are entitled to the complete results, including the index scores and percentiles. If the report shows only a composite, request the full score summary or a meeting to go through it.
Does an IQ score change as my child grows?
It can shift, especially in young children and after real intervention. One score is a snapshot, not a permanent label. If an old number is being used to make a big decision, that is thin ground to stand on.
Is IQ the same as how well my child will do in school?
No. It predicts part of school performance and misses most of it. Attention, anxiety, effort, and teaching matter at least as much, and none of them show up in the IQ number.
Our report lists a GAI that differs from the IQ. Which one is right?
Both are real; they answer different questions. The GAI leans on reasoning and sets speed and memory aside, so when those drag the full-scale down, the GAI often describes your child's thinking more fairly. Ask which one your evaluator is leaning on and why.
A number is a starting point, not a verdict. The parents who get the most out of an evaluation are the ones who keep reading past it.
