The Warrior Gene

The MAOA gene encodes Monoamine oxidase A (MAO-A), an enzyme in the brain that generates neurotransmitters such as noradrenaline, adrenaline, serotonin, and dopamine. They are responsible for the mood, arousal, emotions and impulse control. People with elevated activity produce less neurotransmitters and people with reduced activity of MAOA produce more neurotransmitters.

People with the low activity MAOA,  show higher levels of aggression when excluded from social life or isolated than those with the high activity MAOA. So if somebody has low activity MAOA we could significantly predict aggressive behavior in a high provocation situation, however aggression in a low provocation situation is not significant.