An American gets on a plane and finds himself seated next to an Indian. He immediately turns to the Indian.
"You know," he says, "I've heard that flights will go quicker if you strike up a conversation with your fellow passenger. So, hey, let's talk!"
The Indian, who had just opened his book, closes it slowly and says, "OK, so what would you like to talk about?"
"Oh, I don't know," says the American, grinning. "How about nuclear power?"
"OK," says the Indian. "That could be an interesting topic. But let me ask you a question first. A horse, a cow, and a deer all eat the same stuff -- grass. Yet the deer excretes little pellets, the cow turns out a flat patty, and the horse produces muffins of dried poop. Why do you suppose that is?"
The American guy is dumbfounded. Finally he replies, "I haven't the slightest idea."
"So tell me," says the Indian slowly, "How is it that you feel qualified to discuss nuclear power when you don't know shit?"
I think it's fairly obvious that this joke has been re-ethnicized to reflect current political realities. However, I don't believe it suits stereotypes of either Americans or Indians in today's world! The typical international traveller never wants to talk to his/her fellow-passenger, in part because the flights are so long and the prospect of being stuck with an 8-10 hour conversation is too nightmarish to contemplate, in part because neither passenger may want to talk to a foreigner. My guess is that this joke started out about two passengers of the same nationality but belonging to different social groups/classes.
So my questions are: which nationalities (or infra-national ethnicities) are most likely to have been the subjects of the original joke? Which ones might better suit the current situation? Which Indo-ethnic flavours might be substituted for "American" and "Indian"? Your move.