The Two Sides of Cognitive Masking: A Three-Level Bayesian Meta-Analysis on Twice-Exceptionality

Abstract

We compared the Wechsler scores of individuals with twice-exceptionality (2e) and giftedness using a three-level Bayesian meta-analysis. Ninety-five effect sizes were calculated from 15 studies (n = 2,106). Results show that individuals with 2e who have learning disabilities perform lower than individuals with giftedness in Full-Scale Intelligence Quotient (FSIQ; g = −0.62), working memory (g = −0.79), and processing speed (g = −0.75). Individuals with 2e who have attention-deficit/hyperactivity disorder have a distinct profile in which only processing speed differs from individuals with giftedness (g = −0.55). Results suggest that using a single Intelligence Quotient (IQ) score in the identification process will be misleading. Moreover, IQ may mask the strengths or weaknesses of individuals with 2e.