Figure.
Predicted values for the risk for drug abuse in adopted children from the multivariate analysis of the genetic and environmental risk scores (RS) and the interaction between them on the scale of raw probabilities using an identity link in a generalized linear model. The 10 categories of increasing environmental risk (from 0 to 9) are depicted on the x-axis and the predicted risk for drug abuse on the y-axis. The lines depict the predicted risk for drug abuse as a function of the level of increasing genetic risk (from 0 to 9).