title: Childhood conscientiousness predicts the social gradient of smoking in adulthood: a life course analysis.
abstract: OBJECTIVE
  The social gradient in smoking is well known, with higher rates among those in less advantaged socioeconomic position. Some recent research has reported that personality characteristics partly explain this gradient. However, the majority of existing work is limited by cross-sectional designs unsuitable to determine whether differences in conscientiousness are a predictor or a product of social inequalities. Adopting a life course perspective, we investigated in the current paper the influence of conscientiousness in early and mid-life on the social gradient in smoking and the role of potential confounding factors in a large longitudinal cohort study.
  
  
  METHODS
  Using data from the 1958 National Child Development Study, we examined the extent to which two measures of conscientiousness, one assessed with a personality questionnaire at age 50 and one derived from three related items at 16 years in childhood, explained the social gradient of smoking at age 50 by comparing nested logistic regression models that included social class at birth, cognitive ability, attention and conduct problems at age 7, and educational qualification.
  
  
  RESULTS
  Childhood conscientiousness was a significant predictor of smoking at 50 years (OR=0.86, CI (95%) 0.84 to 0.88), explaining 5.0% of the social gradient independent of all other variables. Childhood conscientiousness was a stronger predictor than adult conscientiousness, statistically accounting for the observed direct association of adult conscientiousness with smoking.
  
  
  CONCLUSIONS
  Conscientiousness may be a predictor rather than a product of social differences in smoking. Inclusion of personality measures and adoption of a life course perspective add significantly to our understanding of health inequalities.
authors.affiliation: Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Pluess
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Mel
authors.initials: M
authors.lastname: Bartley
mesh_terms: D001288:Attention; D002648:Child; D002652:Child Behavior; D003071:Cognition; D005260:Female; D005544:Forecasting; D015438:Health Behavior; D054624:Health Status Disparities; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010551:Personality; D012307:Risk Factors; D012309:Risk-Taking; D012907:Smoking / Q000453:epidemiology*; D012923:Social Class; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology
keywords: Cohort studies; Life course epidemiology; PSYCHOLOGY; SMOKING; SOCIAL INEQUALITIES