Maoa Gene Among Men and Women

In regard to differences between the genders, it is known that men tend to display more boisterous, aggressive, dominating tendencies compared to women who display more caring, nurturing and affectionate roles. Studies have shown that males are three times more likely to have the MAOA-L variation than women. Predominately, this is because women can be heterozygous or homozygous for the gene, whilst men are hemizygous as they only possess one X chromosome, hence they are automatically at a biological disadvantage (Sabol, Hu & Hamer, 1998).

Notably, aggression is not always associated with just men, as high levels of aggression can be seen in females who carry the MAOA- H gene as opposed to men who carry the MAOA-L, as more activity is seen in the male amygdala region (Holz et al., 2014). Additionally, higher hippocampal activation has been associated with materialisation of fear and anger in male MAOA-L carriers and female MAOA-H carriers. This may give further evidence to suggest that negative experiences can provide stimuli for aggressive actions to progress, as this region on the brain is where memories and emotions are heightened (Denson et al., 2009). Controversially, the MAOA-L genotype has actually been linked to observable happiness in women. A recent study proclaimed this theory, in which women women’s happiness levels were measured on a ‘happiness scale’ .

The data revealed that women who possessed the MAAO-L gene were happier than those who did not, also no association between men and happiness was detected. This study is yet to be replicated, ergo the accuracy of the experiment cannot be debated (Chen et al., 2013). On the other hand, women can suffer from low levels of estrogen during their menstruation period, which is linked to fluctuating MAOA levels causing psychological and emotional stress, and violent probabilities (Staniloiu & Marksowitch, 2012). A similar occurrence can be seen with high testosterone and low cortisol levels in males, which has been correlated with social aggression. Testosterone and cortisol are both end products contrived in the hypothalamus-pituitary-adrenal axis (HPA) and this neuropathological region of the brain is devoted to motivation and reward seeking pathways. Hence it can be argued that a high testosterone/low cortisol is a predecessor of threatening and actively seeking risky behaviours (Terburg, Morgan & Honk, 2009). Overall it can be ascertained that continuing research is needed into the female aspect of the MAOA variation as most studies to date have mainly focused on male aggression. Thereupon, clear conclusions cannot be deduced from the evidence available.