Does the language you speak shape how you think?

Anyone who speaks more than one language has probably wondered whether they become a slightly different person when they switch. Some bilinguals report feeling more direct in one language and more polite in another. Behind these personal impressions lies one of the most contentious questions in the study of language: does the language we speak influence the way we think?

In its strongest form, the idea – often associated with the American linguists Edward Sapir and Benjamin Lee Whorf – held that language determines thought, so that speakers of different languages effectively live in different mental worlds. This version has largely been discredited. People can clearly think about things for which their language has no single word, and translation, while imperfect, is possible between any two languages.

A weaker version of the idea, however, has found considerable support. Rather than imprisoning thought, language seems to nudge it, making certain distinctions more salient than others. Colour offers a striking example. Russian has two basic words for what English speakers call “blue”: one for lighter shades and one for darker ones. In experiments, Russian speakers were slightly faster at telling apart two shades of blue when they fell on different sides of this linguistic boundary – an advantage that disappeared when they were given a verbal task that kept the language areas of the brain busy.

Space provides an even more dramatic case. Speakers of some Aboriginal Australian languages, such as Guugu Yimithirr, describe locations using compass directions rather than words like “left” and “right”: a cup is not to your left but to your north-west. Speakers of these languages tend to keep track of their orientation with remarkable accuracy, even in unfamiliar buildings, apparently because their language requires them to do so constantly.

Other research has explored grammatical gender, the way languages describe time, and how speakers talk about accidents. Some of these findings have proved difficult to replicate, and researchers continue to argue about how large and how lasting the effects really are. It is also notoriously hard to separate the influence of language from that of culture, since the two develop together.

What emerges is a more nuanced picture than either the enthusiasts or the sceptics once envisaged. Language does not lock us into a particular worldview, but it does seem to train our attention, encouraging habits of noticing and remembering that differ, at least slightly, from one language to another.

For language learners, this is perhaps an encouraging thought. Learning a new language is not merely a matter of acquiring new labels for familiar things; it may also offer a modest but genuine new way of looking at the world.