Berlin & Kay hue-related basic color categories are compared with the ISCC-NBS system of object color categorization. Though independently derived, categories of the former form a small subset of the latter. A conjecture is proposed that explains the absence of yellow-green and blue-green basic hue categories and the potential for a violet category as the result of constraints on primitive hue category formation due to considerable variation in stimuli selected by color-normal observers as representing for them unique hues.

The Gestalt theorists of the early twentieth century proposed a psychological primacy for circles, squares and triangles over other shapes. They described them as 'good' shapes and the Gestalt premise has been widely accepted. Rosch, for example, suggested that shape categories formed around these 'natural' prototypes irrespective of the paucity of shape terms in a language. Rosch found that speakers of a language lacking terms for any geometric shape nevertheless learnt paired-associates to these 'good' shapes more easily than to asymmetric (...) variants. We question these empirical data in the light of the accumulation of recent evidence in other perceptual domains that language affects categorization. A cross-cultural investigation sought to replicate Rosch's findings with the Himba of Northern Namibia who also have no terms in their language for the supposedly basic shapes of circle, square and triangle. A replication of Rosch found no advantage for these 'good' shapes in the organization of categories. It was concluded that there is no necessary salience for circles, squares and triangles. Indeed, we argue for the opposite because these shapes are rare in nature. The general absence of straight lines and symmetry in the perceptual environment should rather make circles, squares and triangles unusual and, therefore, less likely to be used as prototypes in categorization tasks. We place shape as one of the types of perceptual input that is readily susceptible to effects of language variation. (shrink)