The impact of language on cognition has been hotly debated since the introduction of the Sapir-Wharf hypothesis in the early twentieth century. The Whorfian perspective explains linguistic relativity as the idea that the structure of a language influences a speaker’s perceptions about the world. Universalists, in contrast, propose that perception is an innate, psychological process, unmodified by culture. Central to this discussion is the development and identification of color terminology.
Human visual perception of color is continuous; we can identify the multitude of colors encompassed by the light spectrum. Yet despite this, we only divide colors into a limited number of distinctive categories. The Universal Color Survey, a global study of 110 languages, revealed only eight common color categories across human language: red, pink, blue, green, brown, yellow-orange, purple, and “grue” (green or blue). Moreover, evidence supports that consistent mechanisms drive the naming these categories, proposing there are universal constraints on the separation and creation of color terms, such as color salience and the warm versus cool distinction.
Significant indication of categorical perception exists in infants well before the acquisition of language. In a phenomenon known as the color-category effect, prelinguistic infants identified target stimuli faster when the target and distractor images belonged to separate color categories, for example blue vs. red as opposed to red vs. less red. However, this effect was only evident when shapes where presented in the right side of the visual field. Visual information is processed contralaterally, so information from the right visual field is attended to in the left hemisphere of the brain. Commonly, language related areas are housed in the left side of the brain in adults.
Viewed holistically, this prior research makes a compelling argument in favor of universalism; some elements of categorical color perception are innate, present in children before the appearance of language skills. Until relatively recently though, no studies have examined how these specific categorical relationships are encoded in the brain. Using both infra-red brain imaging and behavioral techniques, Yang et al. sought to remedy this.
In the imaging study, 5 to 7-month old infants were repeatedly presented with 2 colored arrays of geometric shapes, one that alternated within a color category, (ex: various shades of green) and a second that varied across categories (blue vs. green). An example of the stimuli is depicted in Fig. 1. The authors then measured activity in occipital temporal regions of the brain, which interpret and process vision and memory/hearing respectively. Yang et al. recorded distinct responses for the two conditions, suggesting that discrete color categories are represented differently in the visual cortex of the infant brains. Furthermore, in contrast to previous studies, they did not detect any impact from one side of the brain as compared to the other.
The researchers followed-up their imaging results with a behavioral experiment. First, infants were familiarized with stimuli of one color. Then they participated in a comparative test between the original color and a new one. Results indicated that when the second color was from a new color category, infants looked longer at the display. Because infants tend to look longer at novel items, this preference suggests that infants differentiated stimuli according to the color category. Though, it is important to note the converse is not true. That is, the absence of a novelty preference does not indicate that infants cannot make distinctions within-categories5.
The strongest argument for the innateness of categorical color perception comes from mirrored work in adults by the same group of researchers. Repetition of both the behavioral experiment and imaging analysis with adults produced outcomes “qualitatively similar” to those found with children. Yang et al.’s findings maintain that there is “an innate organization of color categories” within visual portions of the infant brain, independent of language knowledge.
Still, the authors do not completely disregard the relativist hypothesis. Linguistic relativism argues that categorical divisions may be colored by the structure of the language you speak. For example, unlike English, Russian makes an obligatory distinction between light blue, goluboy, and dark blue, siniy. Accordingly, Russian speakers were quicker at making distinctions between the two blues than English speakers, demonstrating the impact of linguistic category markers on a perceptual task. Similar conclusions have been reported in work concerning non-Indo-European languages, such as Mongolian. Additional research also implies that category names subtly change perceptual differences among colors, making within-category colors seem much closer together as compared to between-category colors[8,9].
While color categorization exists prior to language acquisition and development, these distinctions may be edited or reinforced in some way by language. Yang et al ultimately adopts this apparent middle ground, unifying information and evidence from both sides of the pedagogic divide. Using comparative studies with both children and adults, Yang et al. were able to identify persuasive evidence in support of the universalist hypothesis.
- Morrill, W., Berlin, B. and Kay, P. (1971). Basic Color Terms: Their Universality and Evolution. Man, 6(1), p.151.
- Lindsey, D. and Brown, A. (2006). Universality of color names. Proceedings of the National Academy of Sciences, 103(44), pp.16608-16613.
- Franklin, A. and Davies, I. (2004). New evidence for infant colour categories. British Journal of Developmental Psychology, 22(3), pp.349-377.
- Gilbert, A., Regier, T., Kay, P. and Ivry, R. (2005). Whorf hypothesis is supported in the right visual field but not the left. Proceedings of the National Academy of Sciences, 103(2), pp.489-494.
- Yang, J., Kanazawa, S., Yamaguchi, M. and Kuriki, I. (2016). Cortical response to categorical color perception in infants investigated by near-infrared spectroscopy. Proceedings of the National Academy of Sciences, 113(9), pp.2370-2375.
- Winawer, J., Witthoft, N., Frank, M., Wu, L., Wade, A. and Boroditsky, L. (2007). Russian blues reveal effects of language on color discrimination. Proceedings of the National Academy of Sciences, 104(19), pp.7780-7785.
- He, H., Li, J., Xiao, Q., Jiang, S., Yang, Y. and Zhi, S. (2019). Language and Color Perception: Evidence From Mongolian and Chinese Speakers. Frontiers in Psychology, 10.
- Jameson, K. and Alvarado, N. (2003). Differences in color naming and color salience in Vietnamese and English. Color Research & Application, 28(2), pp.113-138.
- Roberson, D., Davies, I. and Davidoff, J. (2000). Color categories are not universal: Replications and new evidence from a stone-age culture. Journal of Experimental Psychology: General, 129(3), pp.369-398