One of Terry Pratchett’s neatest jokes in the Discworld novels concerns the troll (big creatures made of rock) system of counting, which entails only the words “one,” “two,” “many” and “lots”—a fact often cited by troll-haters as evidence of their stupidity. What the mockers don’t know is that troll numbers in fact follow a perfectly sensible quaternary system which begins “one, two, many-one, many-two, many-many, many-many-one…”
It’s a gag with a real world parallel: the Amazonian tribe known as the Pirahã, who lack the ability to quantify precisely any group of objects greater than two. And their language, as we’ve discussed in both the magazine and this blog, lies at the heart of a huge debate in modern linguistics, in which nothing less than Chomsky’s theory of Universal Grammar and the fundamental question of how language and thought relate are at stake.
In his latest book, The Stuff of Thought, the noted language and cognition researcher Steven Pinker has now weighed into the debate; and he offers—in my opinion—a brilliantly lucid exposition of just what it means when a remote hunter-gathering tribe cannot subtract three from six.
To conclude that the lack of precise number thoughts among the Pirahã is caused by their lack of precise number words is, Pinker argues, to make “a dubious leap from correlation to causation.” Instead, he points out, we need to realise that the idea of counting is very different to the idea of number:
It’s tempting to equate a use of the number five with the ability to count five things, but they are very different accomplishment. Counting is an algorithm, like long division or the use of logarithmic tables—in this case an algorithm for assessing the exact numerosity of a set of obj…