We leveraged a sample of females who are notably understudied in addiction research. Importantly, AA females appear to be at low risk for both cannabis and cigarette involvement, relative to EA females, both during adolescence (Keyes et al., 2015; Wallace, Jr. et al., 2003) and adulthood (SAMHSA, 2014). Thus, access to related individuals of AA ancestry is a unique aspect of the present study – we are also not aware of other datasets of this magnitude with AA twins. Further, by utilizing a young adult sample, we circumvented concerns regarding lack of adequate opportunity for experimentation with cannabis (Wagner and Anthony 2002).
