Cognitive Abilities in Williams Syndrome

Daniel Miezah1, Associate Professor Melanie Porter1, Associate Professor Jennifer Batchelor1

1Macquarie University, Sydney, NSW, Australia

Most studies have focused on group means in examining cognitive strengths and weaknesses in William syndrome (WS). Studies examining cognitive variations at the individual level in WS are limited. This study examined heterogeneity and homogeneity in cognitive strengths and weaknesses in WS by focusing on individual performance instead of group averages.

The Woodcock Johnson III Tests of Cognitive Abilities, Australian Adaptation (WJ-III COG) was used to assess a wide range of cognitive abilities in a large sample of 49 WS individuals (aged 6 to 39 years). Intra-individual WJ-III COG subtest and domain comparisons were conducted by investigating the z-scores of each WS participant. A cut-off of less than or equal to -1.5 was used to define a significant personal weakness and a cut-off of greater than or equal to 1.5. was used to define a significant personal strength.

Although there was some homogeneity in cognitive strengths and weaknesses at both the subtest and domain level of the WJ-III COG, there was also evidence of heterogeneity across some WJ-III COG domains and subtests, which overall IQ, chronological age, or sex could not fully explain.

Based on these findings, clinicians should be cautious when claiming that a single cognitive profile is characteristic of all WS individuals. Findings have important clinical implications in terms of assessment and management of cognition in WS.


Mr. Daniel Miezah is currently a PhD student in the Psychology Department at Macquarie University. He previously completed a Masters in Clinical Psychology at the University of Ghana.