Performance on a range of spatial and mathematics tasks was measured in a sample of 1592 students in kindergarten, third grade, and sixth grade. In a previously published analysis of these data, performance was analyzed by grade only. In the present analyses, we examined whether the relations between spatial skill and mathematics skill differed…

This study of children from two U. S. states examined associations among four cognitive and academic skills: executive function (EF), visuo-motor integration, mathematics assessed with applied problems, and letter-word knowledge. Before (T1) and after (T2) kindergarten, children (N=555) were assessed using the Head-Toes-Knees-Shoulders (HTKS) EF…

In a previous study, Mix et al. (2016) reported that spatial skill and mathematics were composed of 2 highly correlated, domain-specific factors, with a few cross-domain loadings. The overall structure was consistent across grade (kindergarten, 3rd grade, 6th grade), but the cross-domain loadings varied with age. The present study sought to…

Objective: The goal of this study was to contrast the cognitive phenotypes in boys with 47,XYY (XYY) karyotype and boys with 47,XXY karyotype [Klinefelter syndrome, (KS)], who share an extra copy of the X-Y pseudoautosomal region but differ in their dosage of strictly sex-linked genes. Methods: Neuropsychological evaluation of general cognitive…