PUBLISHED : Sunday, 25 March, 2007, 12:00am
UPDATED : Sunday, 25 March, 2007, 12:00am

Heard the Japanese joke about Prime Minister Shinzo Abe's sex life? The Emperor's? Me neither. I doubt they exist. Not ones you can tell in public anyway, which is odd because in private Japanese people often laugh like drains at their hopeless politicians and tax-gobbling imperial family.

Anyone who buys the myth that Japan's workaholics have no sense of humour should watch television. Every evening, prime-time Japanese television surrenders to a snickering gallery of punning, slapstick-loving comedians on a mission to make exhausted people laugh.

But you'll search in vain for a Japanese version of Spitting Image, Monty Python, Saturday Night Live or the political gags of David Letterman and Jay Leno. Political satire and the laughter that skewers the pompous and the powerful are not in much demand on Japanese airwaves.

So is the Japanese funny-bone underdeveloped, or their sense of irony? A set of exhibitions at the Mori Art Museum in Tokyo may prove illuminating.

The first is The Smile in Japanese Art: From the Jomon Period to the Early 20th Century. If humour is supposed to upset expectations of the normal, then this is indeed a very funny way to spend a wet afternoon. Try keeping a straight face when you see a two-thousand-year-old clay mask that looks like Mr Smiley, or a chubby-cheeked smiling wooden Buddha. Then there's the Farting Contest Scrolls (1867) of Kawanabe Kyosai (1831-89), which shows you all you need to know about out-of-control flatulence. Japan loves its fart jokes.

But the procession of enigmatically smiling faces, gods and animals tells us little about Japanese humour, except that people here, like anywhere, like a good laugh. There's little political and for that you have to go next door, to the 200 or so exhibits in All About Laughter: Humour in Contemporary Art. Here, funny can be brutal.

Makoto Aida's The Video of a Man Calling Himself Bin Laden Staying in Japan (2005), for example, shows the world's most wanted man surrounded by sake bottles, rambling about the hedonistic pleasures of his new home and apparently mocking its political apathy.

And then there are the globe-conquering, disintegrating businessmen of Momoyo Torimitsu, who invented the crawling robot salarymen that took to streets all over the world. Torimitsu's humour has turned darker since 2001. In Horizons (below) the businessmen are now multinational and crawl all over a map of the planet, bumping into one another until heads, legs and arms come off.

That doesn't sound very funny, but what does Torimitsu think? 'I'm not sure if it's funny,' she told a newspaper recently. 'I certainly didn't intend it to be.' Perhaps political humour just isn't very amusing, whereas almost everyone laughs at the farting scrolls.

Both exhibitions run until May 6 at the Mori Art Museum