Large epidemiological studies of almost an entire population in Scotland have found that intelligence (as measured by an IQ-type test) in childhood predicts substantial differences in adult morbidity and mortality, including deaths from cancers and cardiovascular diseases. These differences remain significant after controlling for socioeconomic variables.
How is it that liberals can continue to get away with saying that “IQ tests measure nothing but how well one does on the test,” when we see that IQ does such a great job predicting so many things?
It’s not clear to me why IQ causes increased life expectancy. Tyler Cowen assumes it’s because smart people do a better job self-diagnosing their own symptoms and following doctors’ instructions. I’m sure this is a part of it.
But we know that IQ is a biological trait determined by our genes. Maybe the same genes that cause higher intelligence also have other biological effects which lead to greater longevity?
There seems to be an inverse correlation between IQ and weight. Smart people are more likely to be skinny and stupid people more likely to be fat. Is this strictly a social class issue (it’s not classy to be fat), or is there some sort of biological connection? (Note that being a little overweight actually makes you healthier.)
Link: visit the web page of Linda Gottfredson who authored the article “Intelligence predicts health and longevity, but why?” along with many other interesting papers about intelligence.