Philomena Cunk, the breath-takingly dim-witted arts and history presenter, ought to do a series on classical music, when she's finished her moronic survey of our island race, in Cunk On Britain (BBC2). That might take some time, since she began with the Big Bang, in an account that promises to travel 'from ancient man to Ed Sheeran'.

Cunk, played with a face as cold and immobile as a side of mutton by Motherland actress Diane Morgan, is a send-up of every self-regarding TV personality who ever recited a script while standing on a windswept cliff-edge and gazing portentiously at the horizon.

'She's like an idiot twin sister,' says Morgan. 'Occasionally she'll get things so right you think maybe she isn't an idiot. Maybe she's a genius.'

The TV in-jokes wear a bit thin. But her malapropisms are hilarious: when she talks about the king of the dinosaurs, 'T'yrannical sawdust rex', or the 'Baywatch tapestry', she's in the great comic tradition of Joyce Grenfell and Dame Edna.

The professors and historians facing her pea-brained questions evidently knew what to expect, and played along. Ronald Hutton and Neil Oliver were trying not to giggle -- but full marks to the lady at the National Archives who talked to Cunk like a weary primary schoolteacher.

No, she explained patiently, the Domesday Book isn't cursed. Perhaps they're used to daft questions at the National Archives.

I can't believe I'm the last person to be turned on to Burnistoun's pawky, plooky wit, to move around the workplace shouting "For real!", to instruct the kids that when you find ­yourself dissatisfied with your surroundings, the only reasonable response is "Up the road!" It didn't grab me at the start and I gave up - too soon, because new sketch shows often seem more miss than hit until they get under your skin, and in its third season Burnistoun has got under mine like scabies. Third and last, alas. The "Save Burnistoun" campaign - which I'm prepared to downgrade to the "Gie's a Christmas special at least" initiative in exchange for a month's supply of macaroon bars because, yes, I can be bought - starts here.

My criteria for a winning comedy are: a) Does it make me laugh? b) Are there good-looking burds in it? c) Does it allow me to come over all pretentious about sub-text, deeper meaning and Scottish identity? The answers are yes, yes and yes. Burnistoun seems to be saying that Scotland, formerly a land of inventors, may be stuck in the hoose these days but it continues to embrace the new. Who is Jolly Boy John, home-broadcasting on his laptop in Speedos to techno, if not the son of Jolly Boy John Logie Baird? As Scott, shell-suited mate of the equally sports-casual Peter, puts it: "Even yer maw's life-streamin' noo."

Not all change is good. The "Up the road!" boys loathe trendy ambience when they're out for a drink or a meal. Hairy McClowdry, host of Kiltie Time, incorporates Kanye West and Ryan Gosling into his heedrum-hodrum rhymes but that's deemed acceptable, whereas it's not okay for history presenters to stride around moors, all lustrous of barnet (Neil Oliver, I think they mean you). If there's schizophrenia at work on Burnistoun, well, isn't that the national condition? One thing we can all agree on, I'm sure, is that it's plain wrong for local talent to swan off to Hollywood and come back talking about how great it is to be "Skaddish" (Lulu, Sheena Easton and Gerard Butler, stop it now). If the show's creators, Iain Connell and Robert Florence, ever get to Hollywood - and I'd love to see Burnistoun: The Movie - it's a pretty safe bet they won't make the same ­mistake.