Intelligence and Health – why do they go together?
13 May 2009
Researchers at the Institute of Psychiatry, have found that brighter people are often healthier. It is not known why, although there are several plausible explanations. For example: childhood poverty may harm both health and intelligence; brighter people might more easily learn the benefits of eating well, exercising and not smoking – so they become healthier. Rosalind Arden explains, 'We had a different idea, that there may be an over-arching genetic ‘fitness-factor’ that influences both intelligence and health, regardless of childhood experiences or healthy lifestyles.'
The ‘fitness factor’ may reflect genetic differences between people – differences in the thousands of genes that influence both body (influencing health) and brain (influencing intelligence). The team analysed relationships among intelligence and a diverse set of health measures in a sample of around 3500 middle-aged male US veterans of the Vietnam Era. Half the men had served in Vietnam; the other half had served in the USA, Germany or Korea. The health measures included muscle atrophy, hernia, nose malformation, ear inflammation, club toes, scoliosis, and unusual levels of glucose, ketones, or proteins in urine samples. The team also checked whether smoking, taking drugs, being overweight, drinking a lot of alcohol or serving in Vietnam increased the likelihood of health problems.
'We found that lower intelligence predicted these diverse health problems, and did so more strongly than the life-style factors (smoking, drug use, drinking, obesity, serving in Vietnam). The health problems from head to toe were also mildly inter-correlated with one another, despite having no obvious medical coherence.' said Ms Arden. These results are consistent with the idea that a genetic ‘fitness factor’ influences both bodily health and brain function – an idea that could be tested further with genetically informative data.
Ms Arden continues, 'We agree that our own health-related behaviours (as well as conditions such as poverty) do matter. But the focus of our research is to investigate whether there is also a genetic ‘fitness factor’ that influences both intelligence and health. Our analyses do not prove one exists, but they show that the idea is worth pursuing – and we are.'
Link to the paper: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W4M-4W5M0C5-2&_user=121727&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000010000&_version=1&_urlVersion=0&_userid=121727&md5=45d1bd0e0e9471004382fa0926b0b020
Authors:
Rosalind Arden, Institute of Psyhiatry
Linda S, Gottfredson, University of Deleware
Geoffrey Miller, University of New Mexico