Do the Gifted Score Lower on Measures of Processing Speed for Reasons Substantive or Psychometric? A Simulation Study

Gifted children and adolescents often score lower on measures of cognitive processing speed than on other broad abilities commonly assessed by intelligence tests. Multiple studies have demonstrated that gifted students as a... [ view full abstract ]

Gifted children and adolescents often score lower on measures of cognitive processing speed than on other broad abilities commonly assessed by intelligence tests. Multiple studies have demonstrated that gifted students as a group typically earn mean scores in the average or high average range on measures of processing speed and that individual scores for these lower-order processing abilities range from superior to below average. There is debate in the literature about why this phenomenon occurs. Some experts argue that gifted students work more carefully and slowly than non-gifted peers, while others suggest gifted students may score lower on measures of processing speed because it is not a core reasoning ability associated with giftedness.

Here, we test whether this phenomenon could be the result of the ubiquitous statistical artifact of regression to the mean. Results from recent factor analyses of the Wechsler Intelligence Scale for Children—5^th Edition will be used to generate simulated subtest scores for 10,000 “students” for the 16 WISC-V subtests. Subtest scores will be used to calculate composites reflecting Full Scale IQ as well as the five indexes: Verbal Reasoning, Fluid Reasoning, Visual Processing, Working Memory, and Processing Speed, as per WISC-V directions. We will compute mean scores on the Indexes for students with FSIQs of 130 and above and compute the percentage of these students who scored in various descriptive ranges. Average scores and percentages will be compared to those reported in the research literature.

Because Processing Speed tasks load at a lower level on g, we expect that gifted students will show considerably lower scores on the Processing Speed Index than on the more cognitively complex Indexes. Thus we expect the artifact of regression to the mean to explain—in part, if not completely—students’ lower processing speed scores on cognitive tests.