The average age of the genotyped sample is 34.7 years (SD=11.1) for males and 36.9 years (SD=12.5) for females. Older participants of both sexes scored lower on Novelty Seeking. Male and female means for the four temperament scales are shown in Table 1. In accordance to earlier findings (e.g., Stallings, Hewitt, Cloninger, Heath, & Eaves, 1996), females score higher on the Harm Avoidance and Reward Dependence scales, while males score slightly higher on Novelty Seeking and Persistence. The scales were therefore adjusted for sex and age effects and their interactions for the subsequent association analyses.
