Childhood conscientiousness is not merely an indicator of social class or cognitive ability.

Conscientious children are less likely to smoke in later life, a study has found.

Scientists analysed the personality trait in 16-year-olds and later at age 50, and compared the results to a number of other measures including social class at birth, cognitive ability and attention problems at age seven, social class and the level of qualifications attained at 50, and whether they smoked at 50.

Using data from the 1958 National Child Development Study, they analysed more than 8,000 people born in the UK that year and found that higher conscientiousness scores in both childhood and adulthood were associated with a lower likelihood of smoking at age 50.

“That childhood conscientiousness explained a small proportion of the social gradient of smoking at age 50 − independent of educational attainment, childhood cognitive ability, attention and conduct problems and childhood social class − suggests that childhood conscientiousness is not merely an indicator of social class or cognitive ability,” the study found.

Applying a life course approach, it was childhood conscientiousness rather than adulthood conscientiousness that was most strongly associated with smoking at 50 years

“Applying a life course approach, it was childhood conscientiousness rather than adulthood conscientiousness that was most strongly associated with smoking at 50 years, suggesting that conscientiousness is a predictor of adult smoking behaviour rather than a result of exposure to social inequality across life.”

The study said it is already well known that those from lower socioeconomic backgrounds are more likely to smoke.

Its authors suggest that preventative efforts could be carried out to target certain personality traits associated with health behaviours.

The research, carried out by Queen Mary University of London and University College London, is published in the Journal of Epidemiology and Community Health.