Contrary to previous research, a new study out today finds that people with lower IQs are not necessarily more likely to die prematurely.
Previous studies have found low IQ to be associated with a greater risk of dying young. To try to examine that more closely, Tomas Hemmingsson of the Karolinska Institute in Stockholm, Sweden, and colleagues analyzed data about 43,283 people born between 1949 and 1951. For military service, the men underwent extensive testing, including an IQ test and screening for physical and mental health problems. The researchers then followed the men through 2003. It's the largest study of its kind.
When those who died during the study period were analyzed by IQ alone, the researchers found a clear pattern: the lower the IQ the greater the chance of dying between the ages of 40 and 54. In fact, those with the lowest IQ were more than three times more likely to die early in middle age than those with the highest score.
But when the researchers took other risk factors into consideration, such as childhood social circumstances including socioeconomic status, adolescent behavior and mental health and adult social circumstances, the association between IQ and premature death disappeared, the researchers reported in a study that will be published in the Journal of Epidemiology and Community Health.
The researchers say the findings indicate that it's not IQ per se that increases someone's risk of dying prematurely. Instead, it could be that lower IQ leads to poorer socioeconomic status or other circumstances that are really to blame.
http://voices.washingtonpost.com/checkup/2009/07/is_iq_linked_to_longevity.html
