Lower IQ = higher risk of death, Swedish study finds

A team of researchers led by Dr. David Batty, a Wellcome Trust research fellow at the MRC Social and Public Health Sciences Unit in Glasgow, studied data from 1,000,000 Swedish men who had entered the army at 18. After taking into account if the individual had been raised in a more affluent family, they discovered one key influence on the association between IQ and death: education. The reason, they suggest, could be due to the fact that more intelligent men with higher cognitive abilities were more likely to lead a healthier lifestyle.

"People with higher IQ test scores tend to be less likely to smoke or drink alcohol heavily, they eat better diets, and they are more physically active. So they have a range of better behaviors that may partly explain their lower mortality risk," notes Dr. Batty, who conducted a second study using data from more than 4,000 U.S. soldiers followed for 15 years. The study showed the same correlation between IQ and death rates.

Other studies have been done in Sweden, showing that preschool education and improved nourishment can raise IQ scores. The fact that enhancing educational opportunities can have long-term health benefits has further validated the government's efforts to improve living conditions and education. Dr. Batty also suggests that there may be benefits to simplifying public health information to make it easier for people with lower IQs to comprehend. According to Dr. Batty, messages designed to change unhealthy behaviors are too complicated. "Messages about diet, including how much or what type of alcohol is beneficial, aren't simple, and the array of strategies available for quitting smoking are diverse and actually quite complicated. If you clarify the options available to people who want to, say, quit smoking, in the short term that may have an effect," he says.

News Release: High IQ linked to reduced risk of death   www.sciencedaily.com  March 13, 2009