One of the truisms wheeled out on The Human Face (Wednesdays, 9.10pm, BBC1) is that human faces transmit emotion. Once you have assimilated this, you need to go back and read the dyspeptic interview its presenter, John Cleese, gave to the Telegraph recently, in which he said that making the documentary series had been a "pretty ghastly experience". Now, children, you have the reason why episode one was also a ghastly experience to watch.
At first glance, spending 200 minutes examining the workings of the face might seem a bad idea. But documentary-makers have backed more obscure horses than this and got away with them. Every now and again I have half-wondered why we judge people at, as it were, face value - why praising a woman's smile, for instance, is considered polite but praising her breasts is taboo. I once saw an obituary in the Independent which, by some computer cock-up, was accompanied by a photograph not of the subject's face but of his paunchy stomach. In what way, I thought, was this part of his anatomy less "him" than his face (after all, by the time we are 40 we all deserve the tummy we have got)?
The answer to these questions was provided by the first episode of The Human Face. A face has 44 muscles, making it capable of 7,000 expressions. A breast (and the majority of stomachs) has no muscles and is therefore incapable of expressing personality. So I have that sorted out; and there were some other interesting, anecdote-sized nuggets in this opening film. A kid born with Mobius syndrome had an operation that meant for the first time she could smile. A disputatious couple from England were sent to the "Love Lab" in Seattle to learn how better to read each other's faces. A Cambridge undergraduate who suffered from Asperger's explained to Cleese how he had consciously to compute what his fellow students' expressions meant. In Japan, a school has been set up to teach inscrutable Oriental salesmen to smile, and we saw them practising with chopsticks gripped between their teeth. It was not astonishing stuff, but enough, at least, to share with a drinking companion over a second pint.
So why was the show such hard work to watch? Cleese was in no doubt. Auntie had substituted a predictable, typical BBC science prog for, to quote the Telegraph's paraphrase, "a very funny, mildly subversive overhaul of the traditional documentary". "Why," he asked, "did they ask me to do it in the first place?"
The idea that tiers of BBC executives interfered in the inspired innovations of a comic genius is, of course, highly plausible. But if you saw the programme, you'll know what I'm about to write: that it was the traditional material that worked and the fooling that didn't. Cleese's links, in which he appeared as a nutty university professor aided by his lovely assistant "Janet", as played by Liz Hurley, were terrible. The semi-illustrative sketches he introduced, about "pedestrian rage" (a kind of remake of the Python's Hell's Grannies) or a soap opera starring immobile-faced crocodiles, were desperate, too.
In his professorial guise, he snapped at Hurley's efforts to express emotions and said he knew they should have hired Judi Dench. Hurley put her tongue out. Cleese's rant at the end complaining about the lack of face-to-face human association these days - preceded by worrying footage of Cleese kicking in computer screens - was curtailed when Hurley threw a bucket of cold water over him. As the old Cleese would have said: who writes this rubbish?
"Oh, don't be silly and pompous. You make yourself sound so ridiculous," Hurley told her master mock-crossly, stressing the unintentional theme of the programme, which was an examination of Cleese's emotional well-being.
He did not look well. For a presenter of a programme on human expression, let alone for this country's greatest clown, Cleese was curiously unable to configure his own face into distinct variations. Beneath his greying moustache, his mouth made a variety of grimaces but when it asked Chris, the Asperger's syndrome patient, what they were miming, I was at such a loss that I wondered if I had contracted the disorder myself.
Cleese started out funny - he was probably the only really inspired member of the Pythons - got funnier as Basil Fawlty and then something happened to make him lose his faith in the validity of English humour. After his last successful and sustained comedy performance in A Fish Called Wanda in 1988, he wrote himself into increasingly ill-fitting roles: as an advocate for the SDP, as a toned Bacardi commercial model, as an author of relationship manuals. With The Human Face, he seems to have entered a sinister new phase as prophet. One can only hope that the damage will be confined to an acceptable but minor science documentary series that should have been delivered in sober 30-minute chunks, and will not spread to his professional reputation.
Cleese said in his interview that making the fourth programme, on fame, was a good experience. I hope his good mood transmits itself and the final episode leaves us with warmer memories of him. By the looks of it, however, he has helped the BBC deliver TV's first turkey of the year - a genuine achievement in the week when Crossroads returned.
Andrew Billen is a staff writer on the London Evening Standard