MAOA and brain injury: Exploratory post hoc t-tests revealed no significant differences between the “Absent Biomechanism” group and the “Brain Injury” group [t(214.79) = 1.80, p = 0.171], nor between the “Brain Injury” group and the “MAOA gene” group [t(196.16) = 1.08, p = 0.527], or the “MAOA gene” group and the “Absent Biomechanism” group [t(204.98) = 2.71, p = 0.020] (Figure 2).