A world without time or number

The Pirahã are an isolated Amazonian tribe of hunter-gatherers who live deep in the Brazilian rainforest. The tribe has survived, their culture intact, for centuries, although there are now only around 200 left. The Piraha, who communicate mainly through hums and whistles, have fascinated ethnologists for years, mainly because they have almost no words for numbers. They use only three words to count: one, two, and many.

We know about the Pirahã thanks to an ex-hippy and former missionary, Dan Everett, now a Professor of Phonetics, who spent seven years with the tribe in the 70s and 80s. Everett discovered a world without numbers, without time, without words for colours, without subordinate clauses and without a past tense. Their language, he found, was not just simple grammatically; it was restricted in its range of sounds and differed between the sexes. For the men, it has just eight consonants and three vowels; for the women, who have the smallest number of speech sounds in the world, to seven consonants and three vowels. To the untutored ear , the language sounds more like humming than speech. The Pirahã can also whistle their language, which is how men communicate when hunting.

Their culture is similarly constrained . The Pirahã can't write, have little collective memory, and no concept of decorative art. In 1980 Everett tried to teach them to count: he explained basic arithmetic to an enthusiastic group keen to learn the skills needed to trade with other tribes. After eight months, not one could count to ten; even one plus one was beyond them . The experiment seemed to confirm Everett's theory: the tribe just couldn't conceive the concept of number.

The Pirahã's inability to count is important because it seems to disprove Noam Chomsky's influential Theory of Universal Grammar, which holds that the human mind has a natural capacity for language, and that all languages share a basic rule structure, which enables children to understand abstract concepts such as number. One of Chomsky's collaborators has recently gone on an expedition with Everett to study the tribe. We do not yet know if the Piraha have persuaded him to change his theory.