Executive functions in intellectual disabilities: a comparison between Williams syndrome and Down syndrome.
Williams and Down syndromes show clear, different executive-function weak spots—planning for Williams, shifting and verbal inhibition for Down—so screen and teach accordingly.
01Research in Context
What this study did
Costanzo et al. (2013) compared executive-function skills in two groups: children with Williams syndrome and children with Down syndrome.
They used mental-age-matched peers without disabilities as a baseline.
The team gave each child the same battery of planning, shifting, and inhibition tasks.
What they found
Both syndrome groups scored lower than mental-age peers on most executive tasks.
Williams syndrome showed a unique dip in planning tasks.
Down syndrome struggled more with shifting sets and stopping verbal responses.
How this fits with other research
Tassé et al. (2013) ran a near-identical study the same year and saw the same split: Williams weak in planning, Down weak in shifting.
Hong et al. (2021) pooled 57 later studies in a meta-analysis and confirmed the Down pattern: large deficits in shifting and verbal working memory.
Freeman et al. (2015) added that, within Down syndrome, kids with poorer motor scores also show weaker executive function, so motor drills may boost EF.
Why it matters
You can stop using one-size-fits-all EF checklists.
If you assess a child with Williams syndrome, probe planning first.
If the diagnosis is Down syndrome, start with shifting and verbal inhibition tasks, then fold in motor-heavy activities to double the impact.
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02At a glance
03Original abstract
Executive functions are a set of high cognitive abilities that control and regulate other functions and behaviors and are crucial for successful adaptation. Deficits in executive functions are frequently described in developmental disorders, which are characterized by disadaptive behavior. However, executive functions are not widely examined in individuals with intellectual disability. The present study is aimed at evaluating the etiological specificity hypotheses pertaining to executive functions by comparing individuals with intellectual disability of different etiology, as Williams syndrome and Down syndrome, on different aspects of executive functions. To this aim a battery evaluating attention, short-term and working memory, planning, categorization, shifting and inhibition, was administered to 15 children, adolescents and adults with Williams syndrome, to 15 children, adolescents and adults with Down syndrome and to 16 mental-age-matched typically developing children. The two groups with intellectual disability showed impairment in a set of executive functions, as auditory sustained attention, visual selective attention, visual categorization and working memory, and preserved visual sustained attention, auditory selective attention and visual inhibition. However, a distinctive profile has been found between the two syndromic groups on other executive functions. While participants with Down syndrome were poor in shifting and verbal aspects of memory and inhibition, those with Williams syndrome were poor in planning. The specific weakness and straights on executive functions may support the etiological specificity hypothesis accounting for distinctive cognitive development syndrome-specific.
Research in developmental disabilities, 2013 · doi:10.1016/j.ridd.2013.01.024