Is there any REAL link between Intelligence Quotient (IQ) and dementia?
Many studies have hinted at possible links to low I.Q. and some have found no apparent links at all. Me? I'm no scientist, but I do meet and converse with a lot of people who are living with various types of dementia, and it's my belief that people living with dementia seem by and large to be more mentally astute than comparable groups of people without dementia.
I know, it sounds crazy, but please bear with me while I explain why I believe that that this may be the case.
First, let me explain what IQ is and how it is measured nowadays.
An Intelligence Quotient (IQ) is a number assigned to a person who completes a standard set of tests that are designed to assess human intelligence. The median or "normal" score is 100 and the standard deviation is plus or minus 15. That means that around two thirds of the population has IQ scores between 85 and 115.
Then there are the outliers.. around 2.5% of people score below 70 and 2.5% of people score above 230.
I have a measured IQ of 152 and have been a member of the high IQ society MENSA for over 25 years.
Now here's the interesting thing that got me thinking...
I read about a phenomenon called the Flynn Effect, which, when first proposed seemed to show that there has been a small but consistent rise in average IQ scores over time for the last few decades.
Some of these rises may of course be attributed to changes in testing methods, and it is also the case that there is evidence that there is a decline in IQ amongst the populations of some countries (Norway, Denmark, Australia, Britain, the Netherlands, Sweden, Finland, France and German-speaking countries) a development which appears to have started in the 1990s.
Either way, something very interesting is happening.
Could it be that the the rise in the number of people with dementia is linked to this phenomenon to some degree?
I read a study recently that linked low IQ to incidence of vascular dementia (https://www.ed.ac.uk/news/all-news/dementia), but when I looked at the Scottish children from 1932 who formed the sample, I soon became convinced that it was their unhealthy diets and lifestyles and not their IQs that increased their .risk of vascular dementia.
Other studies have shown that an intellectually stimulating lifestyle is associated with a lower risk for cognitive decline and Alzheimer's disease and related dementia (ADRD), but me observations are the opposite of this.
In conclusion, since my own diagnosis I have entered a world populated by many other people like me, who are living with dementia. I meet with groups of them many times a week. I study these people very acutely. I listen to them intently and I judge their characters and abilities as best as I can, and I have found that people who are living with dementia are generally clever and articulate (as far as their dementia allows). More so in my opinion than I would expect to be the case, even in self-selecting groups such as the ones that I participate in. I'm seeing it with my own eyes. Or am I only seeing the people who have the "get up and go" to put themselves out there? If any academics are reading these humble blog posts, please consider investing in more research into this fascinating area of study.