Mark Steel: Why do people cling to the myth of the nuclear family?

One of the the strange twists about modern science is that it sometimes gets used by the utterly irrational, who claim they've found scientific proof to back up their bonkers theories.

So you get creationists who announce that they've found geological evidence for the great flood, or some fundamentalist Christian will reveal that "new studies of whales suggest they have a larger stomach than we thought, so there was ample room for Jonah to live in one quite comfortably, perhaps creating a kitchen area near the intestine, and he could even have arranged a spare bedroom for guests by knocking through into the liver to create more space."

The latest discovery seems more convincing, because a Stone Age grave has been discovered in which a genetically linked family is placed together, so they've become known as "the first nuclear family." And one newspaper says, "This suggests family values have been thriving since before the time of Stonehenge."

So that settles it. The traditional family is so natural they were doing it in the Stone Age. The sceptical might wonder how we know this grave contains the whole family, as there could have been loads more of them who all lived together communally, but are buried somewhere else. And then it turns out that there is another body buried there that isn't genetically linked, but the discoverer, Wolfgang Haak, explains this was "probably an aunt or a stepmother." Yes that must be it.

Or it might have been the friendly neighbour from the nuclear family in the hut next door, who'd popped round to borrow a piece of flint because he was putting up shelves. And the two men were probably discussing that week's Top Gear, which featured a new type of wheel you could push from nought to 8mph in nine seconds because it was made of fuel-injection rock, while the women flicked through a catalogue for sabre-toothed tigerskin coats. And if they discover the bones of a rabbit somewhere nearby, that will probably have been the family pet, who was probably called Mister Munchkins.

Even better, the buried people appear to have all been killed in a neolithic raid. So this was probably done by some rival permissive liberal tribe full of single parents and transvestites complaining "I'm an Iron Age man trapped in a Stone Age body", in which all order had broken down, as will probably be proved soon when a cave painting is discovered showing loads of them on the Jeremy Kyle show above captions such as "My stepfather keeps leering at my mammoth", and so they all went on the rampage.

No matter how far society moves from the "traditional" family, we still seem determined to impose it on all history. I went to the Viking museum in York a while ago, in which there were models of a supposedly typical Viking family, in which Viking dad was working while Viking mum was making dinner in a pot and the Viking kids played with a Viking dog and cat. They should have had a commentary, with the dad saying "Hello darling, I've had such a hard day at the pillaging office, that darned South-West division missed their target yet again, they've barely massacred more than three villages since the new tax year."

This might have pleased campaigners for the "traditional" family, such as Melanie Phillips, who complains that the current methods for teaching in schools "destroys the unique place of marriage in our society" by "teaching that families include single parents and children in local authority care". So to maintain our values we should not only disapprove of such people, but deny they exist.

A glance through history suggests there's nothing natural about the "traditional" family, and societies have found countless different ways of organising themselves. In hunter-gatherer societies it appears that tribes lived and mated communally, as they depended on a communal effort to hunt and gather collectively. If Jeremy Kyle had been around then he'd have interviewed the monogamous, glaring at a hunter while sat on his haunches and scowling, "So – you only have sex with one other person do you? No one else in the tribe good enough for you, is that it? You make me sick."

The modern family as we know it arose quite recently, as a product of towns and cities. But even then the "traditional family values" weren't always as we'd understand them. In ancient Greece and Rome, for example, it was deemed healthy and proper for male citizens to have male sex slaves, and anyone objecting would have told they were arguing "against nature".

So come on Melanie Phillips, sign up to be a sex slave, and you'll be true to your word in upholding traditional family values.