Smarter people live longer, according to new research published in the British Medical Journal.
Social scientists have long observed a relationship between high intelligence and a longer lifetime, yet the correlation has largely been attributed to factors associated with high IQ.
Those who score well in intelligence tests are more likely to have a degree and earn more, for example: both factors that increase the likelihood of living until old age.
Now, a comprehensive study has bolstered the theory – known as the “system integrity hypothesis” – which proposes that people with a high IQ are innately healthier.
Surveys carried out across Scotland in the 1930s and 1940s recorded the IQ test scores of almost every 11-year-old. Of the participants in the Scottish Mental Survey 1947, 33,536 men and 32,229 participants were examined.
A research team led by Catherine Calvin a professor of psychology at Edinburgh University, analysed the causes of death of those in that age group to determine if there was a correlation between childhood intelligence and how long they lived.
They found one. After accounting for factors such as higher income and smoking, researchers found childhood intelligence was inversely associated with all major causes of death
Particularly strong correlations between lower intelligence and respiratory diseases, heart diseases and strokes were found. An association was also observed between childhood IQ results and death from injury, smoking related cancers, digestive disease and dementia.
Another, weaker connection was found between childhood IQ level and suicide and with cancers not related to smoking.
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