Scientists mind their language

When someone says they’re “going on a hike”, we take it to mean they’re planning a strenuous walk. But it we’re told to “take a hike”, by a different speaker, it’s generally regarded as a demand that we leave the vicinity. And when a news report says we’re going to have an energy price “hike”, it means our fuel bills are going to rise.

Noun or verb? Passive or aggressive? Linguists have long wondered whether languages evolve as an integrated system, or whether different aspects develop independently.

In a study published this week in the Proceedings of the National Academy of Science, a team of researchers has discovered that a language’s grammatical structures – the way in which words are assembled to express thoughts – change more quickly than its vocabulary – the words used – overturning a long-held assumption in the field.

Researchers from the Australian National University, Oxford University, Germany’s Max Planck Institute and Uppsala University in Sweden ran a computational analysis of 81 languages based on a detailed database of grammatical structures and lexicon. They were able to determine how quickly different aspects of the languages had changed.

The languages are all members of the Austronesian family, which comprises most tongues spoken in the region stretching from Madagascar to the eastern Pacific islands.

In general, the team found that grammar was likely to change more rapidly than lexicon.

“The grammatical structures changed much more quickly and seemed to be more likely to be affected by neighbouring languages, while the lexicon changed more as new languages were formed,” says co-author Simon Greenhill.

Colleague Stephen Levinson adds: “This is a bit of an unexpected finding, since many have thought that grammar might give us deeper insight into the linguistic past than vocabulary.

“What is clear is that grammar and vocabulary changes are not closely coupled, even within branches of a family, so looking at them both significantly advances our ability to reconstruct linguistic history.”

As a sidebar to their findings, the researchers concluded a more nuanced approach that combined both grammar and lexicon could allow for a look into the deeper past.

“One of the really cool things we found was that this approach might allow us to detect when and where speakers of different languages were interacting many thousands of years ago,” says senior author Russell Gray.