In order to examine the interaction effect of the two serotonin modulating genes, the 5-HTTLPR and MAOA-uVNTR, on the perception of threatening stimuli, and to test whether this genetic interaction co-varied with the factor gender, this study genotyped the 5-HTTLPR and MAOA-uVNTR, and recorded the MMN elicited by emotionally spoken syllables in healthy male and female volunteers with varying degrees of state and trait anxiety. The gene discussed is MAOA; the disease is Anxiety.