IQ, Socioeconomic Status, and Early Death: The US National Longitudinal Survey of Youth

Objective: To assess whether the association between cognitive ability (IQ) and early mortality is mediated by socioeconomic status (SES) or whether the association between SES and mortality reflects a spurious association caused by IQ. Methods: The participants were from the US National Longitudinal Survey of Youth (n 11,321). IQ was assessed at age 16 to 23 years and the participants were followed up to 40 to 47 years of age. Results: Controlling for sex, birth year, race/ethnicity, baseline health, and parental education, higher IQ was associated with lower probability of death (odds ratio (OR) per 1-standard deviation increas