“…Mean scores for groups of research patients with KS lie below normative averages on tests of general intelligence (Fales et al., 2003; van Rijn, Swaab, Aleman, & Kahn, 2008), and lower intelligence has been associated with poorer working memory and executive function in many studies in the general population (Ackerman, Beier, & Boyle, 2005; Ardila, Pineda, & Rosselli, 2000; Fales et al., 2003; Polderman et al., 2009; Salthouse & Pink, 2008), although these findings are not universal (Friedman et al., 2006). …”