A psychoeducational report sometimes includes two overall cognitive scores that look similar but are not the same: the Full Scale IQ (FSIQ) and the General Ability Index (GAI). When they are close together, most readers never notice the GAI is there. When they pull apart, it raises a natural question: which number is the real one? This guide explains what each score is built from, why they can diverge, and what it means when they do, whether you are reading a child’s report or your own.
Quick Answer
The FSIQ and the GAI are both estimates of general cognitive ability, built from overlapping but different sets of subtests. The GAI leaves out working memory and processing speed, so it can sit higher than the FSIQ when those two areas are a relative weakness. A gap between them is common and not a diagnosis on its own. It is one piece of information an evaluator weighs, not a replacement IQ or a hidden “true score.”
What’s Inside the Full Guide
- What the FSIQ and the GAI are each built from, and why the GAI exists at all
- Why a real gap between them tends to appear (and it is usually about working memory or processing speed)
- How this works the same way on the WISC-V and the WAIS-5, despite looking like different tests
- What a gap can and cannot tell you
- How to turn the pattern into a useful conversation with an evaluator or school team