The family history score and the GRS were uncorrelated (r=0.011). Both family history and the GRS predicted study members’ smoking phenotypes (Table 1). When family history and the GRS were both standardized and included in regression models simultaneously, GRS and family history coefficients were unchanged and remained statistically significant, i.e. genetic risk and family history were independent and additive predictors of smoking phenotypes. In the mediation analyses, adjustment for family history did not change results. Thus, the GRS contained different information about risk for developmental and mature phenotypes of smoking behavior compared to family history.
