The Subtle Interplay between Language and Category Acquisition and How It Explains the Universality of Colour Categories

When studying natural language, one inevitably needs to explain how linguistic signs and constructions map onto semantic concepts. Among concepts, perceptual categories form a special class in the sense that an insight into how they are acquired will have an important impact on theories of linguistic relativism. Linguistic relativism, also known as the Sapir-Whorf hypothesis, suggests an interplay between language and cognition, whereby language and concept acquisition influence each other. Among perceptual categories, colour categories are without doubt the best studied and still their origins and nature are controversial. Stakes are high; as Deacon writing on colour categories puts it ". .. this may at first appear to be a comparatively trivial example of some minor aspect of language, but the implications for other aspects of language evolution are truly staggering. " (p. 120, 1997) Berlin and Kay (1969) first reported the universality of colour categories: the fact that the foci of colour categories show a high degree of similarity across cultures. Their findings have recently been reconfirmed in a large-scale World Color Survey (Kay & Regier, 2003). Although the universal character of colour categories has been disputed (for a recent view see Roberson, 2005), many have accepted it and have put forward hypotheses about the processes underlying it. The most prominent hypothesis holds that colour categories are the result of the expression of innate constraints on colour perception and cognition. A second hypothesis puts forward that colour categories reflect the structure of human ecology. And a third hypothesis suggests that colour categories are culturally learned and puts somewhat less stress on their universal character. Combinations of these three views have received interest as well (for an overview see Steels & Belpaeme, 2005). However, most theories accounting for universalism are rhetorical and