The GAI is a measure of reasoning ability that places less emphasis on working memory and processing speed than the FSIQ does. Both are measured using standard scores, and have a mean of 100 and a standard deviation of 15. In terms of the bell curve, the numbers indicate the same degree of rarity - a GAI of 156 is as rare as a FSIQ of 156, by definition.
Your child's GAI falls more than three standard deviations above the mean. This is very rare.
Your child's PSI falls less than one standard deviation above the mean. Processing speed could be a "bottleneck" for your child, limiting how well he can demonstrate what he is capable of and how easily people will recognize his potential.
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