A simple definition of irony

"Irony, put simply, is a gap between words and their meaning, a space across which speaker and listener exchange a knowing wink."

That's from an article about the rebirth of irony in China. A good read which relates heavily to the humor situation in Korea, particularly among older Koreans. (Course, the vocabulary of the above is a little too complex for my students.)

Why is irony such a uniquely western phenomenon? Though younger Koreans can appreciate ironic jokes more readily than their parents (no doubt a product of increased access to westerners and a popular culture that borrows heavily from the west), the standard mediums for humor remain wit and slapstick.

Here's a total shot in the dark for an answer:
Western society (Europe, North America) is a diverse animal. Immigration and urbanization has thrown together people from across a broad spectrum of cultural histories. Irony grew out of a basic human desire to feel connected. Disparate people used irony to replace the bases of connection (culture, ethnicity, history) that traditionally serve to make people feel part of a community. The 'knowing wink' filled an important social hole left by immigration. Over the decades, irony became fundamentally tied to western culture.

This understanding helps explain why irony is less common in more homogeneous societies like China and Korea. The connectivity provided by the knowing wink is not as important for feeling connected to one's fellow man in these cultures since there are so many other grounds for connection. Though this will change with globalization's maturity, we are still at the inception of this culture clash. And irony, as anyone knows, takes practice.