Last Night's Television - Man on Earth, Channel 4; Miranda, BBC2; Bennett on Bennett, BBC4

Have you noticed the increasing tendency to squeeze people's names into programme titles? Last week, we had Delia's Classic Christmas and Simon Mann's African Coup transmitted simultaneously, which left us only a Radio Times misprint away from true originality: "Delia's African Coup" or even "Simon Mann's Classic Christmas" could really have given us something to think about – a festive menu of Equatorial Guinea Fowl and Eton Mess, perhaps.

Where Delia scores over Simon Mann, of course, is that she enjoys single-name recognition, the sign of a genuine national treasure. But not even Delia gets her name in a programme title twice, which brings me to Bennett on Bennett, a celebration of the national treasure's national treasure.

Twenty or so years ago, as a fledgling local newspaper reporter in north London, I had cause to phone Alan Bennett. If I'd said I was calling on behalf of the Kray twins he could not have sounded more horrified. "Oh no, no thank you," he said, hanging up before I could even stammer out whatever innocuous question I had for him. Mind you, that counted as an in-depth conversation compared with the response of his similarly renowned neighbour, Kingsley Amis, which contained only two words, the second of which was "off!" I later discovered that the grizzled old news editor initiated all hapless young reporters by finding some excuse for them to phone Amis, the journalistic equivalent of sending the new lad in the workshop for a long weight, or a tin of tartan paint.

Where Amis was famously, apoplectically rude, Bennett's telephone manner we preferred to ascribe to shyness. And in this splendid monologue, he offered us a little more insight into his condition. Had there been any newspaper revelations concerning his sexuality, as befell his friend Russell Harty, he suggested that the response of his "mam" would have been: "We don't understand it. You've always been so shy." For Mrs Bennett, shyness was unequivocally a virtue. After all, it was the reason why he still went on holiday with them in his late teens, when his contemporaries were heading off with each other.

Bennett plainly owes his personality to his parents, which he possibly doesn't consider cause for gratitude, since he always seems faintly, apologetically, tormented. But they also gave him many of his most acute social observations and funniest lines, for which we should all be eternally grateful. "A sausage had only to be hoisted onto a stick to become for my mother an emblem of impossible sophistication," he said, looking timorously into the camera.

Beneath the timorousness, though, there is waspishness. Bennett is at his wonderful best when into his aperçus he politely injects a deadly dose of poison. The actor and archaeologist-to-the-nation Tony Robinson was among last night's victims, "capering about professing huge excitement because of the uncovering of the entirely predictable foundations of a Benedictine priory at Coventry. His enthusiasm is anything but infectious ..."

It is probably safe to assume, therefore, that Bennett didn't sit through Man on Earth, in which Robinson capered about professing huge excitement, this time at evidence that throughout the history of our planet there have been periods of climate change, some far more dramatic than the one we seem to be in now, with which our ancestors have either coped resourcefully, or haven't.

Apparently, the Neanderthals ate each other into extinction once the temperature started to plummet, the last stragglers winding up in a cave in Gibraltar, which is no way for any species to breathe its last. Meanwhile, their smarter cousins, homo sapiens, were able to survive climate change because they were more socialised, moving from place to place through trade, and eventually colonising Europe, the continent left vacant by the poor old Neanderthals. How useful this information might be for us, or our descendants, I'm not sure. But it gave Robinson and his film crew a good reason to jet off to lots of different locations, which is the main thing. Three centuries from now some bright spark might even uncover his carbon footprint, initially mistaking it for that of a stegosaurus.

The main source of the comedy in Miranda is that she is a human stegosaurus, huge and hugely unfanciable, which as others have noted is politically not very correct. And if political incorrectness isn't reason enough on its own to love Miranda, there are plenty of other reasons, not least, in our house anyway, that it is the first new primetime sitcom I can recall that unites the whole family, all laughing our socks off. The hugely engaging Miranda Hart also deserves a medal, or better still a Bafta, for reminding us that slapstick can be funny. Not an episode goes by without her tripping over something, or getting stuck in something, which in less assured hands would be justification for throwing a heavy object at the telly, but it takes real deftness to appear as galumphing as that. She might even be the reincarnation of Tommy Cooper. At any rate, she deserves to have her name in the title.