High IQ in Children Leads to Longer Life

It is possible that being smart means you will live longer.

A new study, the largest to date on the subject, suggests that higher intelligence (IQ) in childhood is associated with a decreased lifetime risk of the major causes of death, including heart disease, stroke, smoking related cancer, respiratory disease and dementia. More broadly, the study suggests that lifestyle is a factor in determining the effect of intelligence on longevity.

To test this, a team of researchers at the University of Edinburgh examined the association between intelligence test scores in subjects aged 11 and then leading causes of death in men and women up to age 79. The data camef rom 33,536 men and 32,229 women born in Scotland in 1936 who took a childhood intelligence test at age 11 and whose cause of death data was linked and available up to December 2015.

The causes of deaths in the subjects were coronary heart disease, stroke, cancers, respiratory disease, digestive disease, and dementia. The researchers found that higher chilhood intelligence was associated with a lower risk of death until age 79, after taking account of several factors ("confounders") that could bias the results such as age, sex, and socioeconomic status. Specifically, a higher intelligence test score was associated with a 28% reduced risk of dying from respiratory disease, a 25% reduced risk of dying from coronary heart disease, and a 24% risk of dying from stroke.

The researchers say the study provides interesting results in terms of associating childhood IQ and causes of death, and even accounting for confounders, the results are still significant. "Importantly, it shows that childhood IQ is strongly associated with causes of death that are, to a great extent, dependent on already known risk factors," they wrote in an editorial linked to the study.