The Definition Of Dyslexia Just Been Updated. The First Update Since 2 Decades

2026-10-09T05:21:09Z

Definitions of health conditions matter, because they inform diagnosis, support, treatment, and future research.

Dyslexia has just got its first official definition update in more than two decades, and it's a major one.

Dyslexia is a condition that affects information processing in the brain: People with it may have problems remembering and working through what's presented to them, and that can show up in difficulties with reading, writing, and pronunciation.

The updated definition, published in the Annals of Dyslexia and authored by researchers from the US, is the result of a consultation with more than 15 international experts on the condition, and reflects recent progress in our knowledge of what dyslexia is.

One of the biggest changes here is the removal of IQ tests for dyslexia. Previously, for someone to be diagnosed as dyslexic, there needed to be a 15-point gap between their reading test score and their score on a standardized IQ test – essentially showing their reading was unusually poor given their overall intelligence.

"There were many children that came close to that definition, but just missed that 15-point difference by one point," says educational psychologist R. Malatesha Joshi, from Texas A&M University.

"Because of that, they were not allowed further help.

"We have taken out the brain-based content so people don't think there is something wrong with their brain if they cannot read or have dyslexia."

Previously, someone with dyslexia who scored below par on both reading and IQ might not be identified as having the condition. By taking the "brain-based content" out of the equation, this should catch more people who need support.

The updated definition is also broader when it comes to the causes of dyslexia. The older guidelines suggested the condition was "neurobiological in origin", and while that isn't going away, factors like genetics and environmental influences are now also mentioned.

Full article:

https://www.sciencealert.com/experts-just-updated-the-definition-of-dyslexia-for-the-first-time-in-20-years