In an independent study of twins from Minnesota, the heritability of alcohol problems was greater in urban (49%) than rural (3%) environments among adolescent males (Legrand, Keyes, McGue, Iacono, & Krueger, 2008), replicating the effect observed in the Finnish sample. There was a similar, albeit non-significant, GxE pattern among adolescent females. Parallel patterns of significant GxE were also reported for other types of rule breaking behaviors among males.
