Executive functions and their relationship with intellectual capacity and age in schoolchildren with intellectual disability.
In students with ID or borderline IQ, working memory is the EF most linked to intelligence and the one most likely to inch upward with age, yet teachers still see all EFs as mediocre.
01Research in Context
What this study did
The team visited special-ed classes and gave executive-function tests to students with intellectual disability or borderline IQ.
They also recorded each child’s age and IQ score to see which EF skills track with smarts and which grow as kids get older.
Teachers filled out a behavior-rating form so the study could compare test scores with everyday classroom behavior.
What they found
Working memory was the EF most tied to IQ; fluid intelligence mattered more than crystallized knowledge.
Older students scored slightly better on working-memory and stop-task tests, but the climb was small.
Even when IQ or age rose, teacher ratings stayed stuck at “medium-low” for every EF area.
How this fits with other research
Danielsson et al. (2012) showed kids with ID match mental-age peers on fluency and switching yet lag on inhibition and planning; Sutton et al. (2022) now add that inhibition inches up with age, filling in the growth picture.
McClain et al. (2022) found working memory the weakest EF in toddlers with autism or ID; the new data say the same link holds through high school.
Danielsson et al. (2010) saw no EF change over five years in adults with ID—an apparent contradiction. The gap fades when you notice they studied adults; teens still appear to gain a little ground before plateauing.
Whiteside et al. (2022) showed caregiver EF ratings predict challenging behavior; M et al. echo the low scores but show teachers rate all students alike, hinting that classroom demands may mask individual progress.
Why it matters
For your next assessment, probe working memory first—it keeps showing up as the core EF hurdle across ages and diagnoses.
Don’t trust teacher checklists alone; pair them with direct tests to spot small age-linked gains that rating scales can miss.
When writing goals, expect tiny annual growth in inhibition and working memory, and build supports that work even when IQ stays flat.
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02At a glance
03Original abstract
BACKGROUND: There is certain empirical evidence of, on the one hand, a positive correlation between executive functions (EFs) and intelligence in people with intellectual disability (ID) and, on the other hand, a slower rate of development of EFs in these people relative to people without ID. This evidence is not, however, unequivocal, and further studies are required. METHODS: We analysed the relationship between development of EFs and both age and intellectual capacity, in a sample of 106 students with either ID or borderline intellectual functioning (BIF) at a special education centre [63 boys and 43 girls, 11-18 years old, mean total intelligence quotient (TIQ) of 59.6]. We applied nine instruments to evaluate both neuropsychological development (working memory, inhibitory control, cognitive flexibility, planning, processing speed and verbal fluency) and behavioural development [teachers' perceptions of the EFs of their students by Behavior Rating Inventory of Executive Function - Second Edition (BRIEF-2) School]. ID and BIF groups were statistically compared in terms of mean performance measures in EF tests. We looked at the correlation between EFs and age, and correlations between EFs and intelligence: TIQ, fluid intelligence [measured by the perceptual reasoning (PR) sub-index of Wechsler Intelligence Scale for Children-IV (WISC-IV)] and crystallised intelligence (measured by the verbal comprehension (VC) sub-index of WISC-IV). Regression models were built for variables with strong correlation. RESULTS: In most of the tests used to evaluate EFs, the ID subgroup performed significantly worse than the subgroup with BIF. In general, teachers' thought that participants had 'medium-low' levels of EFs. TIQ, by WISC-IV scale, correlated significantly with scores in all tests for all EFs. The PR sub-index correlated significantly with 14 of the tests for EFs; 35% of the variation in PR can be explained by variation in performance in Picture Span (working memory) and Mazes (planning). The VC sub-index correlated weakly with seven of the EF tests. We found significant correlations in the ID group between age and scores in all tests of working memory and inhibitory control. Age - considering all participants - did not correlate with any of the variables of teachers' perception except for working memory, and this correlation was not strong. CONCLUSIONS: The results of our study are consistent with descriptions of the typical population: (1) fluid intelligence is more related to EFs than crystallised intelligence is; and (2) working memory capacity is the EF most strongly related with general, fluid and crystallised forms of intelligence. The results suggest that as children and adolescents with ID/BIF get older, their capacities for working memory and inhibitory control increase; development of the other EFs studied was less evident. Teachers' perceptions of the EFs of children with ID or BIF were independent of intellectual capacity and age. More research is needed to delve further into the development of EFs in people with ID/BIF.
Journal of intellectual disability research : JIDR, 2022 · doi:10.1111/jir.12885