What genetic mutation is believed to be responsible for increased aggression in males?

The MAOA gene, often referred to as the "warrior gene," is associated with the regulation of neurotransmitters such as serotonin and dopamine, which play crucial roles in mood and behavior. A mutation in this gene, particularly one that leads to reduced activity of the enzyme monoamine oxidase A, has been linked to higher levels of aggression and impulsivity in males. This connection has been supported by various studies indicating that individuals with the mutated variant of the MAOA gene are more prone to aggressive behavior and have a history of violent crime compared to those without the mutation.

The other genetic factors mentioned do not have a well-established direct link to aggression in the same manner. For example, the SRY gene is crucial for male sex determination but does not directly influence aggressive behavior. XX chromosome inversion and Y chromosome deletion pertain more to variations in genetic disorders and their effects on physical and reproductive characteristics rather than behavioral traits such as aggression. Therefore, the association between a mutation in the MAOA gene and increased aggression in males aligns with current understanding in genetics and behavioral psychology.