Cathleen O’Grady writes:

Color is a spectrum: Red fades from orange to yellow, whereas green merges to turquoise, then blue. Languages treat this spectrum in different ways: Some have separate words for “green” and “blue,” others lump the two together. Some barely bother with color terms at all.

“The question is, why?” says Dan Dediu, an evolutionary linguist at Lumière University Lyon 2. Now, he and his colleagues have found evidence for an unexpected answer: People with more exposure to sunlight are more likely to speak languages that lump green and blue together, under a term that linguists dub “grue.” That’s because of the effects of a lifetime of light exposure, the team speculates: Lots of Sun causes a condition called “lens brunescence” that makes it harder to distinguish the two hues.

Lens brunescence is just one of many theories explaining why color vocabulary is so different across languages, says study co-author Asifa Majid, a psychologist at the University of York. Others originate primarily with the environment: One theory holds that people who live near large bodies of water—like seas or lakes—could be more likely to have a word for blue. And if cultures begin to dye clothing with hard-to-produce blue pigments, that could also prompt the emergence of new color terms.

Everyone has their own pet theories, and “people normally test the theory that they like best,” Majid says. So she and her colleagues decided to put all the main ones through the wringer. [Continue reading…]