Cross-­species Assessment of the Linguistic Origins of Colour Categories

This article considers the relation between language and categorical perception (CP) of colour. Two opposite theories are reviewed, the universalist position arguing that categories are universal with an essentially biological origin, and the relativist position that holds that colour categories are essentially arbitrary and derive from colour terms of the speaker’s language. A review of the human literature presents developmental, neuropsychological, cross-­cultural, neuro-­imaging and computer simulation evidence that CP of colours has at least partly linguistic origins. As animal studies also contribute to this debate, we then review evidence of CP in the visual and auditory domains, and pinpoint the inconsistencies of the literature. To make a direct comparison between humans and monkeys, experimental studies compared humans and baboons for their colour thresholds and in a recognition memory task designed to assess CP of colours. Only humans showed better between-­category than within-­category discrimination performance, suggesting species differences in the processing of a colour continuum. That study along with some of our previous research supports the theory of a linguistic origin for colour categories in humans.