Many people, ... base their thinking about boys on the myth that 'testosterone = aggressiveness = boys,' but nothing in the research, mine included, proves that equation to be true … . So why do men behave so much more violently than women do, if there is no male 'violence chromosome'? When boys feel disconnected (from adequate love and support) and afraid of being shamed, when they harden themselves and then put on the macho mask, the one emotion they feel it's acceptable to show, and thus the only emotion they will show, is anger.