"Contrary to popular belief, the ring and pinkie fingers should not be extended, but should rest by curving gently back toward your wrist. There are two theories about this. One considers the Chinese custom of drinking tea in small cups with no handles. The hot tea tended to burn the tender, sensitive skin of the pinkie fingers, causing them to hold them away from the hot cup. The other theory dates back to the middle ages when the gentry, or upper classes ate with only three fingers and the commoners ate with all five. To extend one's pinkie was an indication of arrogance, an inflated self-importance and was really rather rude. So despite the fact that children often play "tea party" and drink with their pinkies raised, it really isn't a considerate gesture and should be eliminated."
link to pinkies up? nope
i always thought it was something like the first idea, as i had trouble holding fancy cups when i was small - it was a sort of balance/don't burn issue