Cognitive Flexibility Deficits in Developmental Dyscalculia: A Robust, Intelligence-Independent Impairment.

Cognitive flexibility deficits are reported in developmental dyscalculia, but their specificity remains unclear. Sixty-four Moroccan fourth-graders (32 dyscalculia, 32 typically developing) completed the WCST-64. A composite Flexibility Z-score was analyzed via ANCOVA, ROC analysis, and Bayesian estimation. The group difference persisted after adjusting for age (adjusted d = 2.23), for working memory and inhibition (d = 2.47), and for nonverbal intelligence (d = 2.54), confirming flexibility-specificity. Diagnostic utility was excellent (AUC = 0.968). The total-sample flexibility-mathematics correlation (rs = -.62) was non-significant within groups, reflecting group separation. The sample-derived cutoff requires external validation.