"Other studies that have assessed initiation of multiple substances confirm the observation that adverse childhood family conditions are associated with a greater likelihood of initiation of cigarette use (13, 14). Conversely, positive parental-adolescent relationships have been associated with a lower risk of cigarette use (15), although this finding is not universal across studies (16). Smoking behavior of social network members and protobacco media influences also have been shown to be important determinants of age at smoking initiation (17)."


Galea, Sandro; Nandi, Arijit; and Vlahov, David, "The Social Epidemiology of Substance Use," Epidemiologic Reviews (Baltimore, MD: Johns Hopkins Bloomberg School of Public Health, 2004) Vol. 26, pp. 37-38.