Last night's TV

Imagine you've arrived in Britain for the first time, on a Monday night in April. Maybe you're an asylum seeker. Or a Martian. You don't really know anyone, or much about the place, so you switch on the telly for a bit of entertainment and company, to help to understand the culture better. What is this place all about? What are the locals like?

Oh. They're a bunch of oikish, foul-mouthed louts with flaky skin and genital warts. And they reproduce while they're still children. That's the impression you would have got from a bit of channel-surfing last night. OK, so it's not quite up there with what's been going on over in Austria, but still, it doesn't make you swell with pride, does it?

Bad Manners Britain: Tonight (ITV1) investigates the disappearance of courtesy in this country. Jonathan Maitland takes a lady called Diana Mather to see if she can teach a pub football team to behave better, and if this will improve their performance on the pitch. Diana's an etiquette coach - one of those ridiculous jobs that only exists because of a certain kind of factual television programme. (Survivalist is another.)

Diana braves the muck of a Mancunian common to try to teach some common-as-muck Mancunians to mind their Ps and Qs and cut back on their Fs. They learn to applaud the opposition; to respect the linesman's decisions; that one pump is quite sufficient when shaking hands. And that one shake is sufficient after urinating on the referee. It's pretty inconclusive, a half-hearted experiment that goes nowhere and shows nothing. Certainly the performance of the team is not improved, and as soon as Diana Fs off back to Chelsea, or wherever she lives, they'll go back to swearing for Britain and throwing milkshakes and ice cream at each other.

Anyway, it's a shame this wasn't better, because the disappearance of manners and the breakdown of society and all those related subjects deserve something more thoughtful. The behaviour gets much, much worse in Embarrassing Bodies (Channel 4). "I'm just going to pop some gloves on and have a little look," are just about the scariest words you'll ever hear. They should be spoken by the doctor, and heard by you and no one else. But no, these people want to share. A young man drops his trousers to show us his thrush. A woman allows us to see a funny growth in her anus.

Stop it! Put them away. I'm very pleased these people are taking their problems to the doctor. But that's where they belong, at the surgery, with no one else there. OK, medical students maybe, but certainly not a camera crew. This is horrid and unnecessary television.

Britain's Youngest Grannies (BBC3) are very young - 35, 36, and one became a nan at 32. Not that any of them behave like grannies. There's no knitting, no rocking chairs, no blue rinses. I doubt this lot smell of biscuits, or anything worse. No, Tara's out clubbing in Norwich, snogging a 21-year-old. He doesn't seem to have a problem with it. He says she's totally a GILF. G, I and L stand for "Granny", "I'd" and "Like to".

Pauline became a gran at 34 when her 15-year-old daughter Leanne gave birth to Cassie. Now they're off out dancing together, in tiny skirts. Not Cassie, she'll have to wait for a couple of years, she's only four. They're from the north-east; it's part of the culture up there.

Tracey in Runcorn is another clubbing granny. She's got two teenage girls - Layla, who has her own little girl, and Kaye, who's got one on the way. It's hard to keep up, I know. It is for Tracey, too; she's having all their names tattooed on her very un-gran-like tummy, in case she forgets. Trouble is, the rate her girls are popping them out, she's going to run out of tummy room quite soon.

They're all lovely really. OK, there are a few regrets about the place, maybe it would have been better to wait a tiny bit. But they all work as families. And this is a surprisingly uplifting film. Maybe Britain isn't such a bad place after all.

What did you think? Have your say at blogs.guardian.co.uk/tv