So it's seen as impolite or "undisciplined" to stick your chop sticks into the rice?
Hmm, I guess it's the equivelant of eating with your hands -- barring finger foods -- in the United States. You're not supposed to do it unless your a toddler, if seen doing so, generally your parents will smack you up-side the head,or at least be like "are you stupid?" Also, used to have the elbows on table thing, but no one seems to care much anymore. Just trying to relate it anyways
. (continues his monologue)
I think the US equivelant developed because it is messy. Wonder why the Japanese chopstick taboo developed...