Nautilus:

When Paul Kay, then an anthropology graduate student at Harvard University, arrived in Tahiti in 1959 to study island life, he expected to have a hard time learning the local words for colors. His field had long espoused a theory called linguistic relativity, which held that language shapes perception. Color was the “parade example,” Kay says. His professors and textbooks taught that people could only recognize a color as categorically distinct from others if they had a word for it. If you knew only three color words, a rainbow would have only three stripes. Blue wouldn’t stand out as blue if you couldn’t name it.

What’s more, according to the relativist view, color categories were arbitrary. The spectrum of color has no intrinsic organization. Scientists had no reason to suspect that cultures divvied it up in similar ways. To an English speaker like Kay, the category “red” might include shades ranging from deep wine to light ruby. But to Tahitians, maybe “red” also included shades that Kay would call “orange” or “purple.” Or maybe Tahitians chunked colors not by a combination of hue, lightness and saturation, as Americans do, but by material qualities, like texture or sheen.

To his surprise, however, Kay found it easy to understand colors in Tahitian. The language had fewer color terms than English. For example, only one word, ninamu, translated to both green and blue (now known as grue). But most Tahitian colors mapped astonishingly well to categories that Kay already knew intuitively, including white, black, red, and yellow. It was strange, he thought, that the groupings weren’t more random.