LAST week, Johnson took a look at some of the advantages of bilingualism. These include better performance at tasks involving "executive function" (which involve the brain's ability to plan and prioritise), better defence against dementia in old age and—the obvious—the ability to speak a second language. One purported advantage was not mentioned, though. Many multilinguals report different personalities, or even different worldviews, when they speak their different languages.

It’s an exciting notion, the idea that one’s very self could be broadened by the mastery of two or more languages. In obvious ways (exposure to new friends, literature and so forth) the self really is broadened. Yet it is different to claim—as many people do—to have a different personality when using a different language. A former Economist colleague, for example, reported being ruder in Hebrew than in English. So what is going on here?

Benjamin Lee Whorf, an American linguist who died in 1941, held that each language encodes a worldview that significantly influences its speakers. Often called “Whorfianism”, this idea has its sceptics, including The Economist, which hosted a debate on the subject in 2010. But there are still good reasons to believe language shapes thought.

Much more: Multilingualism: Johnson: Do different languages confer different personalities? | The Economist