Next year the largest ever Doctor Who exhibition is scheduled to appear at Kelvingrove Museum in Glasgow. Doctor Who is great television and I am happy watching it on the box, but I'd like to fend off any further invasion of our museums and galleries.

Exhibiting popular culture doesn't have to be banal, but it often is. I visited the Kylie exhibition at the V&A in London because I love her style. Expecting to see her clothes up close and examine the construction of her image, I was disappointed. Marketing got visitors through the doors, but few spun around for a second look for there was no substance to the pop queen's display, which can't have been intentionally ironic. Kylie, frankly, would have been embarrassed at the lack of showmanship.

A greatly unappreciated problem in the debate about high and low culture is that the popular, as much as the traditional, is damaged by the pernicious influence of assuming the audience are stupid and need spoon-feeding. The lowering of standards affects pop as much as Proust, Banksy as well as Beethoven. This is amply demonstrated by the changes to Doctor Who on TV, by the headline-grabbing, slavish courting of celebrity assistants (Catherine Tate this time) rather than good actors, chosen in keeping with the plot. They need to wise the Doctor back up or the fans, a cerebral lot, will desert them.

Unfortunately, so-called popular exhibitions are not promoted because someone cares passionately about the subject and wants to show and tell. Instead they are held because curators today don't have the confidence to display a little scholarship - even about hot-pants and Daleks - and think copying an established crowd-pleaser aimed at kids will be a sure-fire success. Museums and galleries should show what we cannot see elsewhere, particularly in our own living rooms. What will be next: The Apprentice at the National Museum?

This is all part of the encroachment of the low-brow and the vacating of the high-brow from the mainstream. It's hard to find serious art today. Listen to any cultural programme on TV or the radio, or peruse the papers, and you'll be hard pressed to discover anything challenging. Instead you will come across grown adults acting like children giggling about the new band, playing the next video game or gossiping about the latest celebrity biography. Editors devote more pages to T in the Park than opera at the Theatre Royal. As for the Proms, well, in a fit of original thinking, this year's programme includes a performance of the theme tune from Doctor Who. High art is the new taboo.

IN a desperate attempt to use celebrity to bolster his image, Gordon Brown - the "I am not going to do celebrity" Prime Minister - received the glamorous film star George Clooney at Downing Street this week. Clooney popped in to No 10 in a break from promoting his latest movie, to "raise awareness"

about Darfur.

While I would find it hard to resist a visit from the screen idol, Gordon and Sarah Brown should shut the door on him. Clooney has a Hollywood interpretation of politics. Of Darfur he stated: "It's not a political issue. There is only right or wrong." Hmm.

So for him, there are no serious political or territorial questions to worry your pretty heads about; it is a morality tale of bad guys and good guys. This simplistic black-and-white picture might work at the box office, but it shouldn't be the script of international politics, which needs to address a far more complicated situation.

Of course it's not just Clooney who wants to elect himself as minister for foreign affairs (with the blessing, it seems, of our political leaders); he is competing with Angelina Jolie, Bob Geldof, Bono and Richard Gere (who at least seems to know a bit about Tibet).

If people want to see what they wear on the red carpet, fair enough, but it is another matter when celebrities colonise the public sphere and social issues.

Unelected luvvies should bow out of this kind of political theatre.

This column comes to you from my parents' house, where I've quietly gone mad in just one week. No matter how long ago you fled the nest, the old relations and interactions slip back when you stay in your old room with the posters still stuck up on the wall.

Mum shouts up the stairs to see if I want my knickers washed. Dad picks up the telephone while I am talking to a colleague to ask if I will be in for dinner. They both wonder what time I will be home before I've even left the house.

It strikes me that while my brother bangs on the door demanding to know when I'll be out of the bathroom, there is a television reality show producers have yet to get their hands on. "I'm a daughter, get me out of here" is one show I would tune in for.

Tiffany Jenkins is director of the arts and society programme at the Institute of Ideas.