You don't say...

"On the whole, the acceptability of taboo words is only loosely tied to the acceptability of what they refer to, but in the case of taboo terms for effluvia the correlation is fairly good. Shit is less acceptable than piss, which in turn is less acceptable than fart, which is less acceptable than snot, which is less acceptable than spit (which is not taboo at all). That's the same order as the acceptability of eliminating these substances from the body in public."