The model’s predictions were tested on illegal behavior in an attempt to validate the actuarial model’s predictive utility. The model’s predicted values were a fairly good predictor of the person having been arrested, used or injected illegal drugs, and driven while drunk. Moreover, the risk factors for externalizing identified two risk profiles associated with high risk of arrest: 1) high peer deviance in later adolescence (predicting a 67% risk) and 2) males with high individual stress during later adolescence (predicting a 54% risk). These findings could reflect two possibilities. First, the risk profiles could reflect causal pathways involving deviant peers and, particularly for males, high stress. Second, the risk profiles could reflect markers of other, unmeasured causal processes. Even if the risk profiles represent markers rather than causal processes per se, they may still be useful in prediction, as was the case in the present study in which the risk profiles were fairly discriminating in terms of risk for arrest. Thus, evidence suggests that the externalizing profiles and their associated risk factors were meaningful for predicting important and costly societal
