Judging by reports, the Pirahã are an ordinary sort of folk. It is said of them that they can be aloof at a first encounter, but that they enjoy chatting and socialising, and that they like a drink or two—not unlike your average Brit. And yet over the last 12 months there has been quite a buzz around this obscure little tribe from the Brazilian rain forest: planes have been landing in their village on a weekly basis, carrying futuristic technical equipment and hot-headed scientists. Last July, John Colapinto, a journalist from the New Yorker, spent a week with them. In April, the magazine ran a lavish 18-page photo feature on the tribe.

Tribal culture, of course, is not only rife in the Amazon, but also in academic circles—an insight that goes some way towards accounting for the hype around the Pirahã. In 2005, the American anthropologist Daniel Everett published