Why some men are more aggressive than others - Men's Health - MSNBC.com

Why some men are more aggressive than others - Men's Health - MSNBC.com: "This form of the MAOA gene, referred to as “low activity,” was associated with aggressive behavior only in men who were cynical and hostile toward others and among those with poorly educated fathers. In contrast, men with the low activity MAOA gene who were not cynical or hostile or whose fathers had at least graduated from high school were no more likely to exhibit aggressive behavior than those with the high-activity form of the gene, study findings indicate.

In other findings, differences in the serotonin 2A receptor, another serotonin gene, were also associated with a higher level of aggressiveness in men. Again, increased aggression was only apparent among men whose fathers had not completed high school. The subjects’ educational level did not appear to be related to their behavior."