Childhood socioeconomic status moderates genetic predisposition for peak smoking

Smoking is the leading cause of preventable disease and death in the U.S., and it is strongly influenced both by genetic predisposition and childhood socioeconomic status (SES). Using genetic variants exhibiting credible and robust associations with smoking, we construct polygenic risk scores (PGS) and evaluate whether childhood SES mediates genetic risk in determining peak-cigarette consumption in adulthood. We find a substantial protective effect of childhood SES for those genetically at risk of smoking: adult smokers who grew up in high-SES households tend to smoke roughly the same amount of cigarettes per day at peak (~23 for low and ~25 for high genetic risk individuals, or about 8% more), while individuals from low-SES backgrounds tend to smoke substantially more if genetically at risk (~25 for low and ~32 for high genetic risk individuals, or about ~28% more).