High intelligence early in life has consistently been associated with decreased mortality, but the mechanisms are still not fully understood. In this cohort study, we examined the association between intelligence in early adulthood and later mortality from natural and unnatural causes taking birth weight, parental socioeconomic position, participants' own education and body mass index into account.
13 536 Danish men born in 1953 and 1959-1961 with data from birth certificates and intelligence test scores from conscription were followed until 2009. Information on vital status was obtained from the Civil Registration System. Mortality risks were analysed by the multiple Cox proportional hazards model.
The risk of mortality from natural as well as unnatural causes was more than twice as high among men in the lowest scoring intelligence tertile (HRnatural deaths=2.24; 1.90-2.65 and HRunnatural deaths=2.67; 2.03-3.53). Adjusting for all covariates attenuated the estimates, but the association remained (HRnatural deaths=1.82; 1.48-2.25 and HRunnatural deaths=2.30; 1.63-3.25).
In men, intelligence in early adulthood was inversely associated with midlife mortality from natural and unnatural causes. The associations remained after adjustments for a range of covariates.
Insights into the causes of variances in physical performance are important to prevent mobility limitations in old age. We examined associations between intelligence in early adulthood and midlife physical performance.
Data from the Copenhagen Aging and Midlife Biobank were analyzed using linear regression. In total, 2,848 male cohort members had intelligence scores from conscription and physical performance measures from midlife.
In adjusted models, a 1 SD increase in intelligence resulted in 1.10 more chair-rises (p