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Table 5 Intellectual ability classifications1 (% of participants) determined by full scale IQ (FSIQ) versus mean normalized score

From: A solution to limitations of cognitive testing in children with intellectual disabilities: the case of fragile X syndrome

Classificationa Males Females
Based on FSIQ (%) Based on mean normalized (%) Based on FSIQ (%) Based on mean normalized (%)
Profound 0.0 3.3 0.0 0.0
Severe 0.0 17.0 0.0 2.2
Moderate 84.8 46.4 20.8 8.7
Mild 10.8 29.4 29.2 16.3
Borderline 3.8 1.3 15.6 26.1
Low average 0.6 2.6 10.4 21.7
Average 0.0 0.0 20.8 22.8
High average 0.0 0.0 3.1 2.2
  1. aClassifications: profound, FSIQ < 25 or mean z < −5.0; Severe, FSIQ ≥ 25 and < 40 or mean z ≥ −5.0 and < −4.0; Moderate, FSIQ ≥ 40 and < 55 or mean z ≥ −4.0 and < −3.0; Mild, FSIQ ≥ 55 and < 70 or mean z ≥ −3.0 and < −2.0; Borderline, FSIQ ≥ 70 and < 80 or mean z ≥ −2.0 and < −1.3; Low Average, FSIQ ≥ 80 and < 90 or mean z ≥ −1.3 and < −0.7; Average, FSIQ ≥ 90 and < 110 or mean z ≥ −0.7 and < 0.7; High Average, FSIQ ≥ 110 and < 120 or mean z ≥ 0.7 and < 1.3. z score refers to the number of standard deviations from the average of the WISC-III normative sample.