Mr. X was administered the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV), which is an individually administered test of a person's intellectual ability and cognitive strengths and weaknesses. The WAIS-IV is comprised of 15 separate subtests and measures both verbal and nonverbal skills. On the WAIS-IV, Mr. X earned a Full Scale IQ of 155, which classifies his intelligence in the Very Superior range and ranks him at the 99.9th percentile when compared with other adults his age. The chances are 95 out of 100 that his true Full Scale IQ falls within the range from 150 to 158. Because Mr. X's Verbal Comprehension Index (148, 99th percentile, Very Superior) and Perceptual Reasoning Index (150, 99th percentile, Very Superior) were not significantly different, his Full Scale IQ appears to be an accurate representation of his general cognitive abilities. This is consistent with his estimated premorbid intellectual functioning, which is thought to be at least in the high average range. As Mr. X did not report any cognitive symptoms or concerns, his scores across these measures of intellectual functioning are thought to be stable and consistent.
His Verbal Comprehension Index is interpretable, as the components do not vary significantly. VCI includes four tasks. The first task, Similarities, consists of using verbal reasoning to draw similarities between two ideas or concepts. The second task, Vocabulary, consists of providing a verbal definition of presented vocabulary words. The third task, Information, consists of answering general knowledge questions which are typically learned during schooling. The fourth task, Comprehension, consists of questions about everyday situations that require judgment and reasoning to answer accurately. Mr. X's VCI score of 148 (99th percentile, Very Superior) suggests that he has strong verbal abilities, and performed well on tasks in school which involved these skills.
Mr. X's Perceptual Reasoning Index (PRI) is also interpretable, as the components do not vary significantly and thus can be interpreted as a single construct. PRI includes five tasks. Block Design assesses the ability to reconstruct targeted designs using blocks with different-colored sides. Matrix Reasoning involves using nonverbal reasoning skills to complete a puzzle from multiple options. Visual Puzzles consists of selecting three of six choices that can be rearranged to recreate a target design. Picture Completion assesses higher-order visual analysis and reasoning, and consists of identifying missing portions of complex pictures. Figure Weights consists of identifying from five choices the weight which would balance a visually-depicted scale. Mr. X's Perceptual Reasoning Index score of 150 (99th percentile, Very Superior) suggests that he excels in the mental manipulation and configuration of visual material, and is able to use reasoning to solve a variety of visual puzzles.