We often hear about people with dyslexia who are particularly intelligent, and some very popular books have probably helped to spread the idea that high intelligence is very common in the context of specific learning disorders. However, these views are based on anecdotes rather than verified data. How much truth is there then?
This is the question Toffanini tried to answer and colleagues a few years ago with their research.
What did they find out?
Before moving on to the results, a premise is appropriate: as already explained in other circumstances (for example in the article on WISC-IV profiles in DSAs), in about 50% of people with specific learning disabilities the IQ is not interpretable due to wide discrepancies between the various indices, mainly due to inefficiencies of verbal working memory. In these cases we resort to the use ofGeneral Skill Index (the set of scores concerning the verbal and visuo-perceptive reasoning tests, excluding the verbal working memory and processing speed tests); this procedure is also justified by some studies that highlight a very high correlation between this index and IQ, although the latter score is more predictive of academic and academic success than the other parameters obtainable from WISC-IV, that is the most used test for intellectual evaluations (in this regard, it may be useful to read our previous article).
Therefore, starting from the assumption that in the case of specific learning disabilities (SLD) it is more appropriate to measure the intellectual level through theGeneral Skill Index (instead of IQ), the authors of this research wanted to observe how often, within the population with ASD, intelligence compatible with the classification of plus-endowment was observed.
Let's move on to the main - very interesting - results that emerged from this study:
- Using the IQ, only 0,71% of people with SLD were over-gifted, while in the general population this proportion is 1,82% (ie in the WISC-IV calibration sample).
Therefore, estimating the intellectual level through IQ, it would seem that among people with specific learning disabilities there are less than half of the gifted than there are in the rest of the population.
- If, on the other hand, we use the General Skill Index (which we have seen to be a more reliable estimate of the intellectual level in specific learning disabilities), it turns out that those with specific learning disabilities are more than twice as many as there are. in the general population, that is 3,75%.
Although with due caution (it is not clear how the sample of people used in this research was selected), the data seem to suggest a much more marked presence of highly gifted individuals within the population of people with ASD compared to what happens among people with typical development.
Further research should shed light on the possible causes of this phenomenon.
You may also be interested in:
- The influence of IQ on academic performance: from beginning to end of school
- Does the level of education influence the intellectual level?
- High cognitive potential and specific learning disorders
- ADHD and IQ. What aspects affect school performance?
- The relationship between creativity, intelligence and executive functions
- ADHD in plus-endowment
- Intellectual profiles with WISC-IV in specific learning disorders
- Rowe, EW, Kingsley, JM, & Thompson, DF (2010). Predictive ability of the General Ability Index (GAI) versus the Full Scale IQ among gifted referrals. School Psychology Quarterly, 25(2), 119.
- Scott, KA (2006). Is the GAI a good short form of the WISC-IV ?.
- Toffalini, E., Pezzuti, L., & Cornoldi, C. (2017). Einstein and dyslexia: Is giftedness more frequent in children with a specific learning disorder than in typically developing children ?. Intelligence, 62, 175-179.