Traditional intelligence tests might underestimate the co-occurrence of learning disorders and giftedness

A study recently published in the journal Intelligence suggests traditional IQ tests underestimate the co-occurrence of giftedness among children with learning disorders.

Previously, children with above average intelligence who also have a learning disorder have been labelled as ‘twice-exceptional’ because it has been argued that children who struggle academically are often gifted intellectually. This claim has comes from anecdotal evidence of famous people such as Albert Einstein and Leonardo da Vinci who both suffered with learning disorders.

It is thought that above average intelligence could be the result of a brain abnormality caused by the learning disorder itself. However, other scientists argue that children with learning disorders are usually less intelligent and cases of giftedness are very rare. So far, research has not focused on how often a child with a learning disorder presents as extremely intelligent.

In answer to the ongoing debate, Enrico Toffalini (University of Padova), Lina Pezzuti (Sapienza University of Rome) and Cesare Cornoldi (University of Padova) analysed the data from 1,413 children who were diagnosed with a learning disorder and had been assessed by the Wechsler Intelligence Scale for Children-IV. The children were scored for intelligence using an IQ cut off of 130 for giftedness.

It was found that the frequency of a child with a learning disorder also being intellectually gifted depends on the way in which intelligence is measured. When intelligence was determined using the WISC-IV and a cut off of 130, the probability of having a gifted child with a learning disorder was low.

But when an alternative method was used, the General Ability Index (GAI) that measures reasoning ability (and excludes working memory and processing speed), the giftedness in children with a learning disorder was more frequent compared to typically developing children.

Profound differences in age dependent abilities between the groups of children were also exposed. The working memory of gifted children with a learning disorder and typically developing children were similar at a young age but by the age of 16 the former had fallen behind and became equal to the ability to non-gifted children with a learning disorder. In terms of processing speed, gifted children with a learning disorder improved the fastest and matched the ability of gifted typically developing children.

Overall, the study has shed light on the assumption that all children with learning disorders have a deficit in processing speed, because in fact it appears to be overcome by gifted children with a learning disorder.