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Hi Everyone,

I am reaching out for some advice regarding a recent IQ test my 6 year old son performed.
His WIAT-III scores came back much higher than his WISC-V score.
The psychologist told me that he is overachieving against his IQ and other kids will eventually catch up.
She did make note of potential ADHD-I but says the IQ will remain fairly fixed regardless.
The IQ test & WIAT were conducted on the same day and it was the first time he had met her - she also made note he potentially suffers with performance anxiety.
Since then he has now been formally diagnosed adhd (inattentive) by a pediatrician
My questions are:
Would the IQ remained fixed with adhd? I imagine there are accommodations in place for a reason
The difference in WISC to WIAT look like they may be statistically significant - shouldn�t this be further investigated?
Is it possible he didn�t perform to his ability on that day?

I have a hard time reconciling he is overachieving given that from what I have read the environmental factors have to line up as well as a drive to work hard.
My son is clocking off the moment he can and not a second later.
I will also note that his school were extremely surprised by the psychologist report and said they expected much higher FSIQ score.

The results are as follows:
VCI - 106 66%
VSI - 102 55%
FRI - 118 88%
WMI - 117 87%
PSI - 118 88%
FSIQ - 118 88%

His WIAT-III results range from the 96 to >99.9 percentile with most being 98-99%.

Any answers or advice would be greatly appreciated

Welcome!

Some context may help:

1. cognitive (IQ) scores are not considered really stable until children are a little bit older, often around age 8 or 9, and some children with neuroatypicalities (such as ADHD) don't really settle into being fully testable (i.e., showing the full range of their abilities in on-demand testing) until even later than that.

2. when considering whether the difference in scores is relevant, we typically consider whether it is statistically significant (often p<.05 or .01), rare (base rates in the standardization samples often <10%) and meaningful (real-life impact). It's important also to recognize that regression to the mean has much more dramatic effects with outlying scores.

To give you a sense of the ballpark for significance, it may help to know that most achievement measures have correlation of about .6 with most cognitive measures. So, for example, if we took his FSIQ as the measure of cognition, and tried to predict achievement, we would expect achievement scores around the 75th %ile. Conversely, if we start from the achievement measures (let's say 98th %ile, since that's where they cluster), and try to estimate cognition, we would predict cognition at about the 90th %ile. The latter is actually pretty much where his scores fall.

2b. here's another way to ballpark this: if the 95% confidence intervals for the measures you are comparing touch/overlap, then a reasonable rule of thumb says the difference is not particularly significant. If there's a big gap between the envelopes, the difference might be more worthwhile investigating.

Bottom line: the scores are neither necessarily fixed/best representation of ability, nor are they necessarily "wrong" per se. He is very young, has never (I gather) experienced this type of testing before, and has neuroatypicalities. I would take these scores as a reference point in time, and no more.

Thanks aeh

I really appreciate the time you have taken to respond and help clarify the information I was given.
It�s hard to think that education can at times be so dependent on this number.
Fortunately I have heard from the school and they are going to deem him as 2e and continue his extension work which will obviously help him with his self soothing behaviours too and other challenges he faces.

Thanks again!