Testosterone, aging, and the mind
Harvard Health Publications
Volume 5 Issue 4
1/15/2008

When med (and for that matter, women) think about the powers of testosterone, they are not likely to consider mental processes. Indeed, the male hormone has much more obvious roles in a man's body. Still, new research suggests that testosterone may have a surprising role in masculine mentality.

Although testosterone is the most potent male hormone (androgen), it is only one of many. When the ancient Greeks provided the name, they chose well: "androgen" comes from the words for "man maker," and, indeed, androgens make the man, or at least his characteristic male traits.

Testosterone has many direct effects on the male anatomy and metabolism. It is responsible for the deep voice, increased muscle mass, and strong bones that characterize the gender. It stimulates the production of red blood cells by the bone marrow. The hormone also has crucial, if incompletely understood, effects on male behavior: It contributes to aggressiveness, and it is essential for the libido (sex drive), as well as for normal erections and sexual performance. Testosterone stimulates the growth of the genitals at puberty, and it is responsible for sperm production throughout adult life. Finally, it influences cholesterol metabolism, but scientists are still not sure how that affects health.