The populist mood is seductive. When you are caught up in a focus group or planning meeting it can feel reasonable to give the sovereign consumer what he or she wants. Participants have to shake themselves into realising that if they followed the same principles with the young, children would never learn to read and write. In the end, populism always ends up as the truest version of elitism, because it assumes that the peasants do not want their little heads bothered with difficult ideas. In TV, such condescension manifests itself in a sly form of documentary making, which employs stratagems that divert rather than illuminate.

Take the recent Horizon, "What's the Problem with Nudity?" The documentary makers wanted to ask why humans do not have fur, when other primates do. The scientific consensus is that our ancestors lost their fur when they evolved the means to sweat profusely through naked skin. Their ability to cool themselves had the evolutionary advantage of allowing them to develop large brains, which did not overheat in the potential pressure cooker of the skull cavity. There is hard evidence behind the supposition. A genetic analysis of lice shows that the lice that live in the fur of chimpanzees and the lice that live in human hair diverged into separate species as our branch of the primate family tree parted and our line lost its fur. Unfortunately, you only have to glance at the debate to worry that a modern editor may well decide that it is not "sexy" enough for mainstream television.

So one did. Instead of concentrating on sweat glands, Horizon looked at sex glands. It went further than Big Brother dared and took eight "ordinary people" to a London house and asked them to walk about naked for a weekend. For the first 12 minutes of a one-hour documentary, the crew confined itself to recording their embarrassment at showing their wobbling bodies.