Less "manly", more nurturing?

     A study of men in the Philippines find a dramatic testosterone drop in men after their wives give birth...especially in the men who are involved the most in their child's upbringing.
    The explanations range from an evolutionary trait that keeps fathers from straying, to a child-rearing emasculating effect on new Dads.
     The TIME story  linked above doesn't say whether or not men who adopted children had any drop in testosterone levels, but that would have been be a nice control group to measure.