Cognitive Profiles of French Individuals with Williams Syndrome and Down Syndrome: What's Up? What's Next?

The aim of our study was to characterize the face recognition skills, theory of mind skills, and language skills of a single group of French participants with Williams syndrome (WS) compared to a group of participants with Down syndrome (DS). Twelve French-speaking participants with WS and 12 French-speaking participants with DS took part in this study. The two groups were matched for nonverbal and verbal levels. We used the Benton Facial Recognition test to study the groups' ability to recognize faces, the Theory of Mind Test Revised, and the morphosyntactic production and morphosyntactic comprehension subtests from the French test battery "Instruments pour le Screening et l'Approfondissement de l'examen des DYsfonctionnements du Langage chez l'Enfant (ISADYLE)". The results of the participants with WS were systematically better than those of the participants with DS. Nevertheless, although they outperformed the participants with DS, the participants with WS were far from performing at ceiling level. Most importantly, we found no significant correlations between performances on the various standardized tests for either group of participants. The evaluation of cognitive skills in a single group of French participants with WS confirmed that they present a complex profile. Because these competences are strongly influenced by social and cultural aspects, it is therefore essential to develop studies for specific languages, including when one is examining a rare developmental disability.