David Robson in Aeon:
If you don’t speak Japanese but would like, momentarily, to feel like a linguistic genius, take a look at the following words. Try to guess their meaning from the two available options:
1. nurunuru (a) dry or (b) slimy?
2. pikapika (a) bright or (b) dark?
3. wakuwaku (a) excited or (b) bored?
4. iraira (a) happy or (b) angry?
5. guzuguzu (a) moving quickly or (b) moving slowly?
6. kurukuru (a) spinning around or (b) moving up and down?
7. kosokoso (a) walking quietly or (b) walking loudly?
8. gochagocha (a) tidy or (b) messy?
9. garagara (a) crowded or (b) empty?
10. tsurutsuru (a) smooth or (b) rough?
The answers are: 1(b); 2(a); 3(a); 4(b); 5(b); 6(a); 7(a); 8(b); 9(b) 10(a).
If you think this exercise is futile, you’re in tune with traditional linguistic thinking. One of the founding axioms of linguistic theory, articulated by Ferdinand de Saussure in the early 19th century, is that any particular linguistic sign – a sound, a mark on the page, a gesture – is arbitrary, and dictated solely by social convention. Save those rare exceptions such as onomatopoeias, where a word mimics a noise – eg, ‘cuckoo’, ‘achoo’ or ‘cock-a-doodle-doo’ – there should be no inherent link between the way a word sounds and the concept it represents; unless we have been socialised to think so, nurunuru shouldn’t feel more ‘slimy’ any more than it feels ‘dry’.
Yet many world languages contain a separate set of words that defies this principle. Known as ideophones, they are considered to be especially vivid and evocative of sensual experiences.