Jack -- our department head has a number of pop publications about the
origins of kissing, one of the main theories being that it developed from
the sharing of prechewed food between mother and child.  I've always thought
it a little hard to swallow (pun intended) because there are many cultures
where people do not kiss lips to lips, neither parent with child nor adult
to adult.  In Mali, mothers do kiss children on various parts of their
bodies, but NEVER on their lips, as mouths are considered to be full of
germs (which of course, they are!).
Kathy D.
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