Language diversity around the world

DESPITE the idea that English is spoken in America, Chinese in China, and Russian in Russia, most of the world is far more diverse than the presence of big national languages suggests. In fact, monolingual countries are hard to find. The chart below measures language diversity in two very different ways: the number of languages spoken in the country and Greenberg's diversity index, which scores countries on the probability that two citizens will share a mother tongue. America, Russia, Brazil, China and Mexico have over 100 languages each, but score relatively low on the diversity index, because English, Russian, Portuguese, Chinese and Spanish have grown to the point where they threaten to destroy the many tiny native languages. By contrast, linguistic rivalry and relative poverty have kept a single language from dominating countries like India and Nigeria, which score high on the diversity index. Geography is an additional factor. The many islands of Indonesia and the Philippines shelter small languages despite those countries' middle-income status. Both poverty and geography combine to make Congo and Papua New Guinea the most linguistically diverse countries in the world.