Hormones are not only responsible for sexual differentiation, but also influence other physiological processes, and acts directly on the central nervous system.

For example testosterone, the primary male Androgen is at the highest blood concentration in the early morning hours. This reflects to what the other poster was saying about evolution.

Men are primarily hunter-gatherers, and early morning hunting was the most successful at securing food.

High blood concentrations of testosterone influence aggression and subsequently courage. Rightfully so for hunting and gathering at the break of dawn. In contrast, an aging man's testosterone level declines rapidly.

Evolutionarily speaking, a man's need for high blood concentrations of testosterone at 60 isn't required. The reproduction years, and hunting years are left for younger males. However, all is not done when males age and androgens decline. Older males still play a vital role in human evolution as wisdom and guidance for the young are now his purpose.

For women, estrogen is the primary androgen. When women go through menopause very distinct shifts in both the body and mind are seen - Such as hot flashes and uncontrollable mood swings. Some women report during menopause feeling "crazy".

I've read cases of famous athletes taking androgen inducing substances becoming enraged and committing heinous acts of violence. Similarly, I've read cases of women committing the same during a menopausal induced outrage.

This said, I think there is a strong correlation between androgen levels and assertiveness and aggression in the criminal disposition. There could also be abnormal endocrine disruption occurring. The same may be true in certain people's fear and regression.