Clever children live longer, according to a new study which found that having a high IQ is strongly associated with the length of your life. People with lower IQs don't live as long on average.
Scientists from the University of Aberdeen and University of Edinburgh matched the results of intelligence tests given to all 11-year-olds attending Aberdeen schools in 1932 with survival up to 76 years. The findings are published this morning in the British Medical Journal.
The researchers managed to track down 2,230 of the 2,792 people who took the test in 1932. They found that those who died before reaching the age of 76 had a significantly lower IQ as a child than those who managed to reach that age.
The effect was stronger in women than men, the researchers report, partly because men with high IQs were more likely to have died on active service during the second World War.
The researchers were also able to measure the increased risk of dying before age 76 on the basis of IQ. Women with an IQ deficit of 15 points at age 11 had only a 75 per cent survival compared with those with the top IQs. Women with a 30-point deficit were only half as likely to survive to age 76 compared with their cleverer sisters.
The scientists admitted they did not understand why but believe that measuring childhood IQ "was a significant predictor of human survival".
Many studies had shown up the inequalities in health and length of life when comparing different socio-economic groups. "People living in deprived conditions generally suffer more illness and die younger," the authors noted. Socio-economic status, educational level and mental ability were all "closely related".
Attempts had been made to separate the effects of IQ from social class and education in other studies. The two tended to divide when statistically controlled for. "This indicates that mental ability is not entirely a surrogate for social class and vice versa," the authors said.
