Attention Fathers:

"Testosterone, that most male of hormones, takes a dive after a man becomes a parent. And the more he gets involved in caring for his children —changing diapers, jiggling the boy or girl on his knee, reading "Goodnight Moon" for the umpteenth time— the lower his testosterone drops."
NY Times (9/12/11)

A just released medical study (see below) clearly indicates that men who became fathers had a Testosterone decline more than double that of childless men. Dr. Lee Gettler at Northwestern University checked the Testosterone levels of 624 men at age 21 and brimming. Five years after becoming fathers, their Testosterone levels had dipped as much as 34 percent. The steepest decreases occurred among men who reported that they acted as the primary caregivers of their children.
               Published study in "Proceedings of the National Academy of Sciences"               September 2011