The finding that the genetic risk associated with rs16969968 was reduced in subjects with high parent monitoring, and increased in subjects with low parent monitoring suggests that exposure to low parent monitoring during the middle school period creates an environment that allows for greater opportunity to express this genetic predisposition. These results are in line with findings from the Finnish twin studies, which suggest that parent monitoring modifies the importance of genetic influences on adolescent smoking; genetic influences assuming a far greater importance at low levels of parent monitoring (28, 29).
