hormones are chemicals produced in the body by glands,
Testosterone- primary sex hormone in males linked with aggression, several studies have found that high testosterone is correlated with increased aggression and that low testosterone is correlated with decreased aggression,
Genetics- an important biological mechanism of aggression that may tie in with other biological factors, eg a person may have genetics that predispose them to low serotonin activity, or genetics that encode for limbic system abnormalities,
