In conclusion, we modeled the genetic architecture of smoking behaviors in African Americans living in Detroit. We constructed a GRS that predicted cigarettes smoked per day and accounted for ∼3% of the overall variance in the trait. In addition, significant additive interactions were observed between this GRS and aspects of the individual's social context, including the experience of traumatic events and neighborhood social cohesion. This study provides support for the utility of the GRS as an alternative approach to the replication of common polygenic variation, and gene–environment interaction, in smoking behaviors. In addition, this study suggests that interventions should target individuals who have experienced traumatic life events and emphasizes the potential importance that promotion of neighborhood-level social cohesion may have in diminishing genetic vulnerability to smoking behaviors.
