ADD / ADHD, Dyslexia, Science, Web/Tech

Genetics and Learning Disabilites

One of my read-everyday blogs is Kevin McGrew’s Intelligent Insights. Kevin is an expert in the concept of IQ / intelligence and sometimes his postings can be a little intimidating in their technicalities but they are always worth reading and I learn something from every post. Today, he has two posts which caught my eye. One on genetics and learning disabilities, such as ADHD, and the other on memory and intelligence which I shall blog later.
The ‘generalist genes’ hypothesis is reversal of the common perception of genes’ roll in learning and ability. Rather that saying that gene X causes problem Y, the generalist gene hypothesis argues that genes that affect one area of learning, such as mathematics performance, are largely the same genes that affect other abilities. Although there are some genetic effects that are specific to each ability.
The full study “‘Generalist genes’ and mathematics in 7-year-old twins” is not yet been published but Professor Robert Plomin website does have some information on the massive twins early development study behind the research.
The generalist gene theory is important information in the debate over what is dyslexia. A debate that can be boiled down to two opposing views. Either dyslexia is:

A) A specific neurological problem that sets sufferers apart from other poor readers


B) Just an extreme form of the problem all poor or struggling readers experience.

Note: Dyslexia under both (A) and (B) is not just a reading problem but reading is a benchmark for academic ability.

The common view of genetics and learning problems fits in with option (A), that there is one or more specific genes that cause the problems. Where as ‘The Dyslexia Myth‘ and the generalist gene hypothesis argue for option (B), that dyslexia is just the bottom end of the scale of learning abilities.
This is a critical debate in education. The range of reading abilities in a normal classroom conforms to what statistians refer to as standard deviation. An easy example of it is people’s hight. Most people are about the same height, some people are a bit taller or a bit shorter, a few people are noticeably taller or shorter and at the extremes are a handful who have medical problems such as dwarfism.

In the classroom the large blue areas represent the average kids as most children are average. The green and yellow areas represent those who either do really well or struggle in school. The red area represents those who just fail, for whatever reason, in school.
Option (A) would describe those children in the red area as dyslexic and that apart from their dyslexia those children would be in one of the other coloured areas. Option (B) argues that those children in the red are no different from those in the yellow area, just that much less able.
To education and society the difference between those two opposing points of view is huge. If (A) is true then those children in the red area need specialised (expensive) teaching specific to their disabilities, such cerebellum based exercises. But if (B) is true, those children need the same education that everyone else is getting, just a lot more of it. If society gets this choice wrong, then either we will waste huge amounts of money on specialised education that does not work or waste huge amounts of money on traditional one-to-one teaching methods that don’t work. Getting this wrong will costs us all financially and leave some children with crippling learning problems.