The proposed path model provided a good fit to the data (see Figure 2) and study variables accounted for approximately 5% of the variance in maximum number of drinks (included SNPs collectively accounted for 1.6% of the variance). The only genetic polymorphism with a direct effect was 5-HTTLPR; those with the SS genotype had higher rates of maximum number of drinks. Findings indicate a mediating role of behavioral control in the association between GABRA6 rs3811995 and externalizing behavior. Those with the CC genotype had lower rates of behavioral control. In turn, behavioral control negatively predicted externalizing behavior. From a statistical perspective a direct association between the independent variable and the outcome is not necessary to establish indirect effects (Hayes, 2009). In fact, this indirect effect was significant (0.54, 95% BBCI = 0.25 – 0.97) with 42.3% of the total effect of GABRA6 rs3811995 on externalizing behavior operating through behavioral control. Behavioral control also had a direct effect on maximum number of drinks. The indirect effect of GABRA6 rs3811995 on maximum number of drinks through behavioral control was significant (0.17, 95%
