Disrespectful Americans

When MR asked Why don't American kids respect their parents more I was also reminded by an incident when we were in Bangkok last summer. We were in a Skytrain when four teenagers came running up the stairs and burst into our train car. "Dude! I can't believe you did that!" one them said loudly and they proceeded to talk loudly and laugh amongst themselves, mainly about drinking and hwo they got drunk. They didn't seem to notice that Thais are generally reserved and the ride on the Skytrain is almost peaceful and quiet. Is this another example of American boorishness and the stereotype of the "Ugly American" abroad? This leads then to the question: Does disrespect of parents also lead to disrespect of others and other cultures? (Quite a leap for a causal chain to be sure.)