Wacky Kissing Hypotheses And Kissing As A Commitment Check Mechanism
The wacky hypotheses for why we kiss include, from medicine, the dental hygiene hypothesis -- that people kiss to generate saliva, to improve dental hygiene. From the Human Behavior and Evolution Society Conference in Albuquerque Saturday.

"If (the dental hygiene hypothesis) were true, you'd want to kiss more after a meal." -- Dr. Aaron Goetz

(Yuck!)

Goetz sees kissing as an honest signal and a commitment assessment mechanisn. (Kissing is "costly" because it transmits bacteria.) It helps you assess romantic partner's commitment to a current romantic relationship. Basically, says Goetz, by kissing, you're saying, "I'm so committed to you, I'm willing to put my health on the line." (You're also asking your partner, "Are you that commited to me?")

Goetz' prediction: Partners with lower mate value should initiate more kisses than partners with higher mate value. And Goetz found, in his research, that this seems to be true (that the lower mate value partner needs to assess the relationship level more).

A book about signaling that I love -- Zahavi and Zahavi's The Handicap Principle: A Missing Piece of Darwin's Puzzle.