The androgenic (male) hormones that are associated
with anger stimulate action. They are more in men.

Another reported personality difference is that
women internalize their feelings to a greater
degree than do men and blame themselves for
incompetence or failure, which leads to
depression, while men blame others, which leads to
anger.

http://ajp.psychiatryonline.org/cgi/content/full/154/12/1641

Current difinition of Irritable Man Syndrome(IMS):

A state of hypersensitivity, anxiety, frustration,
and anger that occurs in males and is associated
with biochemical changes, hormonal fluctuations,
stress, and loss of male identity. Whereas
feelings like anger, anxiety, and frustration can
occur quickly and end quickly, irritability can
develop into a mood state that can last over a
long period of time and can trigger these feelings
over and over again.It can have a major impact on
our whole lives.

http://filipinofriendfinder.com/blog/swettie_pie47/

http://mentalhelp.net/poc/view_doc.php?id=2772&type=book&cn=116

Recent research suggests that men who have poor
anger management skills are more likely to suffer
a heart attack before age 55 than their more
emotionally controlled peers.

http://mentalhelp.net/poc/view_doc.php?type=doc&id=5809&cn=116