Pajamas are at the center of a hotly contested public etiquette controversy in Shanghai. On any given day in the major Chinese city, people can be found on the streets wearing pajamas. Jammie-haters suggest that the practice is unclean, disrespectful, and classless. Jammie-wearers, however, argue that there is nothing inappropriate or wrong about the habit.

The pajama situation is more widespread than you might think. A survey recently revealed that 25 percent of the population had family members who regularly wore nightclothes in public. Because many homes do not have indoor plumbing, the daily walk to the bathhouse with a towel and a toothbrush in PJ's is as much about comfort as it about necessity.

It's a little unclear how this debate will be resolved. Will it take a strictly-enforced decency law? Or will the public outcry shame folks out of wearing their pajamas on the streets? Who knows. One thing is certain, though, this culture clash isn't about to go away anytime soon.