A recent study has suggested an answer to a question that has occupied philosophers for centuries: Do people need words in order to think? A tribe living in the Amazon basin could provide the answer. The Piraha tribe 1 be small — there are only about 200 members all told – but they exhibit a fascinating cultural peculiarity. These people have no words for numbers, 2 from ‘one’, ‘two’ and ‘many’. What is more, their words for ‘one’ and ‘two’ are very similar. As 3 as anyone can tell, this tribe has never had any sort of vocabulary for numbers, but 4 appear to survive quite well without it. It was soon realised that these people might supply an insight into the way our minds work. Studies have shown that adult members of the tribe are no 5 at counting than a baby is at speaking. When they were shown a row of objects and asked 6 duplicate the number they saw, they could not get beyond two or three before starting to make mistakes. This applies even to adults who appear reasonably intelligent in every other way. So it looks 7 though the Piraha are not very good at counting simply because they do not have a vocabulary for numbers. This would suggest that human beings in general cannot think 8 they have no words to do so.