I have recently been reading Malcolm Gladwell’s new bookOutliers: The Story of SuccessI have to say that I found a lot of it irritating as I thought his arguments were very polemic and with lots of flaws, although he is a great storyteller and writer. There are however, two interesting chapters on high IQ in the book. As a neuropsychologist who assesses IQ, I sometimes get people telling me that they or their children have very high IQ’s normally over 150 and sometimes over 200. I am never sure when this comes from as on the most commonly used test of IQ in the US and UK, the Wechsler scales, the highest IQ you can get is 160. In Gladwell’s chapter he discusses the case of Chris Langan a person with one of the highest IQ’s in the US, with an IQ of 195.

I think a lot of people think that having a high IQ is a very valued attribute and thus claim to have a high IQ in order to impress. What people don’t seem to realize is that IQ is not an interval scale i.e. like a ruler, getting higher in equal measures. Instead IQ is a comparison scale, it compares your score to others. About 50% of the population have an IQ between 90 and 110 making this level of IQ normal. A further 46 % have either a high IQ from 111-130 or a low IQ between 89 and 70. Only 2% have an IQ below 70 (classed as a learning disability) and 2% or 2 in a 100 people have an IQ above 130. An IQ above 148 would place you in the top 1 out of 1000 people. However a high IQ isn’t always a good thing. Gladwell describes how Chris Langan’s life has been one of underachievement, he now lives on a farm looking after animal with a relatively quite life. Gladwell also looked at a long term study of a group of very high IQ kids who had been followed up. They also hadn’t done that well. Gladwell argues that whilst a higher than average IQ predicts good education etc beyond a certain point (about 120) ‘having additional IQ points doesn’t seem to translate into real world advantage’ (p79).

In my clinical practice I have only rarely seen children with an IQ over 130 and those that I have seen seem to have found it difficult. They tended to be socially isolated partly because they couldn’t relate to their peers. But also a good proportion of these children had a social communication disorder (Asperger’s syndrome). In a way a very high IQ is abnormal. Only a very few people have it and there must be some odd process in development/evolution for it to occur. It doesn’t seem to give any particular benefit and often is associated with difficulties. So my advice is to be careful in wishing for a very high IQ for you or your child in this regard it is probably better to be average or high average.