Figure 1

Do personality types confound associations between alcohol and unsafe sex or is alcohol an intermediate factor on the causal pathway between personality and unsafe sex?. In the confounding theory, the association between heavy drinking episodes and unsafe sex (arrow B) is explained by the confounding factor of personality types (arrows A). In this model, a reduction in heavy drinking would have no effect on unsafe sex as personality types are independently associated with unsafe sex (Arrow C). In the causal pathway theory, heavy drinking is an intermediary factor in the causal pathway between personality types and unsafe sex (arrow D plus E). Prevention of heavy episodic drinking would reduce the portion of unsafe sex attributable to arrow E, though will have no effect on the contribution of arrow F.