Urinal 101: piss n' spit

I’ve been meaning to bring this topic up for some time, and after the recent article http://www.straightdope.com/columns/030509.html, the time seemed right.

For the longest time I thought it was an odd quirk of mine: When I scoot up to the bowl I will gather a ball of saliva and drop it down into the water, then pee, or sometimes just as the flow starts. And often I drop another ball upon completion of my bladder evacuation. Recently I started to notice, at public urinals, a hell of a lot of other men do this too!! Is this some inherited trait, or a learned behaviour (from whom I have no idea)? Do women also feel compelled to do the same? And lastly, WHY??? I can’t seem to stop myself from this odd habit!

Since women don’t use urinals, I really doubt they spit into toilets before using them.

There have been threads on this in GQ. And no one has an answer or even a viable theory.

The best one was: It’s a chance to spit in a controlled environment.