The impact of behavioural executive functioning and intelligence on math abilities in children with intellectual disabilities.
For students with mild ID, math growth hinges on working memory and flexible thinking, but severe inhibition problems cancel the usual IQ boost.
01Research in Context
What this study did
The team looked at kids with mild intellectual disability. They asked: which thinking skills help these kids do math?
They tested working memory, flexible thinking, inhibition, and IQ. Then they saw how each one linked to math scores.
What they found
Weak working memory and stiff flexible thinking hurt math scores the most. Higher IQ helped only when inhibition problems stayed low.
Once inhibition problems hit the clinical range, IQ no longer predicted math success at all.
How this fits with other research
Maehler et al. (2016) found the same thing: working memory, not IQ, drives school success in primary kids with ID. The new study adds that high inhibition can wipe out the IQ link entirely.
Bigby et al. (2009) looked like a contradiction. They saw equal working-memory deficits in low-IQ and normal-IQ kids with learning disabilities, so they said IQ does not matter. The key difference: their group had learning disabilities, not ID, and they did not test how inhibition changes the picture. When inhibition is severe, the IQ effect vanishes; when it is mild, IQ still helps.
Danielsson et al. (2012) mapped the EF profile earlier: kids with ID show good verbal fluency but poor inhibition, planning, and non-verbal working memory. Bouck et al. (2016) now link those exact weak spots to math performance.
Why it matters
Screen working memory and inhibition before you write a math goal. If inhibition scores sit in the clinical range, do not count on IQ to carry the student. Instead, build lessons that cut memory load and give clear stop cues. Short chunks, visual prompts, and timed response cards can bypass the blocked path.
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02At a glance
03Original abstract
BACKGROUND: Little is known about the role of behavioural executive functioning (EF) skills and level of intelligence (IQ) on math abilities in children with mild to borderline intellectual disabilities. METHOD: Teachers of 63 children attending a school for special education (age: 10 to 13 years; IQ: 50 to 85) filled out a Behaviour Rating Inventory for Executive Function for each student. Furthermore, students took a standardised national composite math test and a specific math test on measurement and time problems. Information on level of intelligence was gathered through school records. Multiple regression analyses were performed to test direct, moderating and mediating effects of EF and IQ on math performance. RESULTS: Behavioural problems with working memory and flexibility had a direct negative effect on math outcome, while concurrently, level of intelligence had a positive effect. The effect of IQ on math skills was moderated by problems with inhibition: in children with a clinical level of inhibition problems, there was no effect of level of intelligence on math performance. CONCLUSIONS: Findings suggest that in students with mild to borderline intellectual disabilities and math difficulties, it is important to address their strengths and weaknesses with respect to EF and adjust instruction and remedial intervention accordingly.
Journal of intellectual disability research : JIDR, 2016 · doi:10.1111/jir.12276