If there is one thing that is ubiquitous to Shanghai, it’s people walking around in their pajamas. At any time of day or night, it’s not uncommon to see people out and about grocery shopping, walking their dog, playing mahjong, or just sitting around and gossiping while in their pajamas.

Nobody seems really sure how this pajama fad started in Shanghai, but one theory is that it started back in the 1930s or so when having an extra set of clothes to use as sleepwear meant that you were wealthy. The next logical step was to parade around in these PJs to let all your neighbours know that you could afford the good life.

Another theory is that being in your pajamas all day suggests that you’re so well off that you don’t need to work and can afford to live a life of leisure. You know, like Hugh Hefner.

I’ve also heard some other more practical reasons:

• Pajamas are cooler and more comfortable during Shanghai’s extreme heat (I don’t buy it – I see people in pajamas all year.)
• A lot of older Shanghai residential buildings have/had communal toilets, so people became used to seeing their neighbours in pajamas. Eventually the acceptable PJ-comfort zone just extended to the rest of the city. (Maybe, but I don’t buy it. Shanghainese are very class conscious. Wearing pajamas out in they city like this would be like wearing a sign that says you are not rich.)
• Shanghainese (and Asians in general) don’t use dryers. On laundry day, people just stay in their pajamas because they’re waiting for their clothes to dry (If so, why is this pajama phenomenon limited to Shanghai?)

Whatever the origin, Shanghainese people have been happily walking around their neighbourhoods in their pajamas for decades whenever they feel like it.

That is, unless Haibo and some Shanghai World Expo 2010 fascists have anything to say about it. Some people seem to think that having a bunch of citizens walking around in their pajamas is uncivilized, makes the city look bad, and may give foreign visitors a bad impression.

What the hell? Let people wear whatever the hell they want. To quote one Shanghainese man’s response to the anti-pajama crowd:

‘My pajamas were bought abroad and they are much better and more expensive than your clothes’.”