Suckling, even in adults, results in a lowered heartrate/blood pressure.  I am
referring to some data I read (no, I didnt keep the citation, sorry) that
indicated studies of adults having sex showed men's heart rates dropped
dramatically while suckling.  Apparently there is a powerful physiological
connection between the act of nursing and heart rate, as well as blood
pressure (the other thing measured in this article.)  Makes sense, of
course--we all know how calming nursing can be to an anxious/frightened/hurt
little one.  Evolution seems to have provided suckling as a way to "reset"
physical calmness.

Any more thoughts?

Joy Berry-Parks               "Childhood decides." --Jean Paul Sartre
Attachment Parenting Group of AR
LLLL, Little Rock
evolutionary anthropology student