Fig 3. The simulation results of smoking, drinking, and marijuana use levels in Sunshine High under various scenarios setting coefficients to zero.

Note: mtos–effect from marijuana use to smoking; mtod–effect from marijuana use to drinking; mtosd–effects from marijuana use to both smoking and drinking; infs–peer influence effect in smoking; infd–peer influence effect in drinking; infm–peer influence effect in marijuana use; selm–peer selection effect in marijuana use; selall–peer selection effects in smoking, drinking, and marijuana use; all–all above effects.