In the presence of the interaction there were main effects of MAOA-LPR on hyperactivity in girls at age 4 (β = 0.33; 95% CI: 0.11 to 0.55; p = 0.003) and age 7 (β = 0.29; 95% CI: 0.07 to 0.51; p = 0.01) such that in girls exposed to little or no adversity, the high activity MAOA-LPR allele was associated with greater hyperactivity (Figure 1, B1, B2). There were no main effects of MAOA-LPR independent of the interaction.
