Objective. Conscientiousness is a strong predictor of health behaviours and better health outcomes. However, longitudinal data from representative samples of the population and from adolescents are rare. Therefore, the objective of this study was to establish whether school-related conscientiousness was associated with the onset and change in alcohol drinking and cigarette smoking frequency, in a large representative cohort of school pupils in England.
Methods. A school-related conscientiousness facet in the Longitudinal Study of Young People in England (LSYPE, N= 15,770) was identified, which had concurrent validity with conscientiousness and its facets. Latent growth curve modelling (LGCM) was used to model initial alcohol drinking and cigarette smoking frequency, over 4 years of the study.
Results. For all pupils, higher conscientiousness predicted lower initial alcohol drinking across 4 years (from year 9 to 12). In females, higher conscientiousness was marginally associated with a slower rate of change in the move from non-drinker to drinker (linear slope), but significantly associated with a faster upturn in this change (quadratic slope). Higher conscientiousness predicted non-smoker status, greater initial cigarette smoking frequency for pupils (in smokers) but a change towards less frequent smoking (in smokers). Associations were not explained by parental educational, income, or monitoring; regularity of seeing friends; psychiatric morbidity; or birth weight.
Conclusions. School-related conscientiousness is an important facet, predictive of health behaviour onset and change during adolescence. The study illustrates the value of representative population samples that allow researchers to study associations between personality traits and health behaviours over time.