The D-I-Y University: Week 3 Day 2 Anthropology

He made quite a spectacle, the outsider with the strange, short clothes, tagging along in the high African grass, repeating his exasperated questions to the men hurrying to their midday chicken oracle. It was wrong to think that they were primitive or foolish, of course - all those commemorative rituals at his public school for the massed slaughter of the recent First World War had shown up that presumption - but what they had told him of their society was certainly not making his task any easier.

It seemed a world expressly designed by lunatics. Everyone believed there were witches around, and that to find out if someone else was bewitching you, you needed to feed poison to a chicken while going through the name of possible suspects, and when the chicken fell over dead, you knew who it was.

Edward Evan Evans-Pritchard pushed along to catch up with these men he'd come to like, and helped them set out the nervously flapping fowls in the growing heat. It still seemed impossible, though, for poisoned chickens can't talk. He thought about it at length back in the house he'd had built in the village.

What if the whole thing was just a way of channelling a small community's tensions? It wouldn't matter which name the chicken fell over at. You'd be happy - and tension in the village would be reduced - if anyone on that list apologised to you.

Everything that had seemed odd about these people clicked into place. The village was a steam engine, and these rituals were an elaborate network of feedback devices. Buying the chicken and the poison was expensive, expressly so, because that kept the release valves from being weakened through over-use. All the chicken's pronouncements had to be cleared through the local prince, which meant the ritual could never go too far, and threaten the village's good order. It was a great, self-correcting equilibrium system, hidden in the social rules.

Evans-Pritchard had the discovery of his career, and anthropologists' hunts for subtle pathways took off afresh. If a tribe holds that the blood from a murdered person pollutes local rivers, he pointed out subsequently, you shouldn't just examine it in terms of their religious beliefs. Look at how it restricts local murder rates, too. If Indians won't eat wandering cows, yet another researcher said, then think of the cows as mobile petrochemical factories, supplying useful cooking fuel and fertiliser.

Not everything evolved so neatly, but in moderation you get a powerful new imaging scope, which it was increasingly tempting to turn back on to the society left behind. In one possible view, Parliament is opened when an elderly human wearing dead animal furs and with a pile of stones balanced on her head publicly waggles her vocal cords. In another, though, Elizabeth Windsor is a crucial force for stability, allowing even individuals who disagree with an elected government to stay united. Along with the time-stiffened boxes of the class system, her country will avoid the terrified social uncertainties that lead to witchcraft charges, as in early 1950s America, or its PC-churning campuses today.

Claude Levi-Strauss hunted potential harmonies in a different fashion, starting from the way villages avoid dividing into separate factions - often by simply having strict rules against marrying within a faction. Terrified young brides or grooms end up being flung into distant groups, which may not be the greatest of pleasures for the new couples, but has the effect of neatly stitching the entire mass of factions together - at least till their children grow up, isolated in the new factions, and the elaborate stitching needs to be repeated. The rules and stories that summarise this process have a recurrent form: showing what needs to be joined, even if everyone knows that it will ultimately break apart.

This line of reasoning can lead you to suspect that there will be similar, equally potent rule machines around us. Young men step into the magical box called a squash court, and just by thwacking a little ball around, two utterly separate ideals they've been taught - the need to compete, but also the need to accept shared rules - are joined together. A few hours of ordinary life will rip that sewing apart - just as the tribal marriage circuit decays - but that just means the therapy will need to be regularly repeated. Readers of popular romances are equally known for their need to buy fresh recharges for their Mills and Boon hope machines.

The weavings in myths, sports and marriage are remarkably similar, and remarkably powerful. Since words and rules can survive long after the world they came from has vanished, they can be used as a coded time-machine, stretching back; stopping along the way, perhaps, at the beliefs of one young Englishman, in the 1920s, convinced that there might be wisdom to garner in distant lands.

Tomorrow: Language