The Secret Life of the Family (Wednesday, 8pm, BBC1) started with a variation of the zoom that used to introduce News at Ten, a shot originating in outer space and ending up in central London. Instead of Westminster, however, we zeroed in on a very desirable modernist residence in north London, the home of the actors Paul and Janine Bentall and their three children. My first reaction was that One Foot in the Grave, in which Mrs Bentall had a recurring role, must have paid better than I imagined. My second was to wonder if the producer of this documentary, Jeremy Turner, had chosen a family of thespians for his subjects because of their aptitude for faking authenticity.
His choice never was explained, but it was quickly apparent, unless I have been double-bluffed, that this was an honestly made film. Having admitted that two weeks of recording had been condensed into a single day, the programme also acknowledged fly-on-the-wall's Heisenberg effect when the artificiality of the barbecue party thrown by the Bentalls was held to be the result not of any social deficiency on the part of the hosts, but of the presence of the cameras.
But the family's secrets were so fascinating that you soon ceased to worry if the carpet bugs you saw magnified were the precise ones resident in the Bentalls' rugs. Stylistically, the show was a cross between Being John Malkovich, one of those early Nicholson Baker novels that footnoted the mundane in obsessive detail, and the title sequence of The Six Million Dollar Man. In content, it was popular science at its most interdisciplinary - every move the Bentalls made was watched by a panel of godlike commentators from a remote studio: Dr Duncan Dymond, the physician; Barbara and Allan Pearce, a preternaturally handsome pair of antipodean behavioural researchers who seemed to take pleasure in patronising their own species; and Amanda Ursell, a nutritionist whose somewhat disappointing contributions included her hope that the family liked their hamburgers well done.
None of the secrets uncovered by the cameras and extrapo-lated by these experts was good news, however. The alarm clock that awoke Paul pushed up his heart rate alarmingly, allowing Dr Dymond to remind us that most coronaries occur in the morning. In the bathroom mirror, Paul examined his thinning hair while we examined the microscopic creatures living among its remaining roots. There was danger everywhere. The dog brought fleas. The bathroom soap and the dishcloth bred bacteria. A thousand leagues under the kitchen sink lay a "mysterious underwater world" that even Domestos could not conquer.
When Edmund Leach, in his famous 1967 Reith lectures, spoke of the family's "narrow privacy and tawdry secrets", he did not mean head lice and dust mites, and there were times when you wished for a bit more social science from this documentary, which tended to race to biologically determinist conclusions. Janine's temper tantrums were diagnosed as menopausal. Her 15-year-old son's snatched kiss with a party guest was parsed in Regent's Park terms. "He's taken the initiative, but she has the more dominant role," said Barbara Pearce, as if talking about a lower primate. And the scientific explanation for the mutual attraction felt by Mr and Mrs Bentall was that they looked very similar - adduced by some impressive computer morphing.
Until this documentary, Janine, who played the mousy nurse in Abigail's Party, must have thought that Mike Leigh was the cruellest social observer she would ever work with. She now knows better. A microscope is crueller. The programme concluded with the BBC's unofficial theme tune, "Perfect Day", ironically serenading what was left of the Bentalls' dignity. I can find no higher praise for The Secret Life of the Family than to wish it had been at least three programmes.
Seven more episodes of Flatmates (Wednesdays, 9.30pm, Channel 4) - perhaps the sloppiest use of "formatted reality" yet seen in prime time - are, on the other hand, seven too many. In episode one, five yuppies in Brixton advertised for a flatmate and whittled the five applicants down to one by a process of haphazard interviewing, making each one choose three new objects for the sitting room and assemble a garden bench from its flat-pack. At least form matched content - the careless, twentysomething lifestyle being reflected in the show's lacklustre production values and the chirpy cynicism of its ringmaster, Emma Kennedy. This was a game-show version of This Life (which is standing up pretty well, incidentally, to its rerun on BBC2) and a lot less compelling.
Like the Bentalls, the Brixton Five paid for selling their souls to the box. Under the pressure of appearing cool in front of the cameras, they chose camp Sean, the applicant who felt his "insane sense of humour" was his best selling point. As the end credits rolled, the house's pre-existing lads admitted that, a few weeks on, Sean was turning out to be a bit more gay than they had thought and inhibited them from calling the goalie a poof when watching Match of the Day. The girls, a particularly viperish pair of sisters, had written him off as friend material. I hope that Flatmates soon finds a household that someone might sensibly aspire to be part of - and I trust the bedbugs get these charmers.
Andrew Billen is a staff writer on the London Evening Standard