very rarely show their cards, unless it's a super card straight flush or royal, went to showdown, in other cases do not show card in general, I think it's stupid and not cultural, because in the future such mooves are remembered and hung the label of Donk. Do not recommend doing so to anyone, because after these mooves opponents will catch up, the logic is clear, such moves are used to stir up the opponent (s) and then if the opponent leads nit style of play is the only benefit.