# Differences in color perception across populations may shape color naming

Mathilde Josserand, François Pellegrino, Dan Dediu, Serge Caparos

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Mathilde Josserand, François Pellegrino, Dan Dediu, Serge Caparos. Differences in color perception across populations may shape color naming. 57th Annual Meeting of the Societas Linguistica Europaea, Aug 2024, Helsinki, Finland. hal-04913940

HAL Id: hal-04913940

https://hal.science/hal-04913940v1

Submitted on 27 Jan 2025

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# Differences in color perception across populations may shape color naming

Mathilde Josserand, François Pellegrino, Dan Dediu & Serge Caparos

(Laboratoire d'Eco-Anthropologie; CNRS; MNHN; Université Paris Cité UMR 5596, Laboratoire Dynamique du Langage; CNRS UMR 5596; Université Lumière Lyon 2, Department of Catalan Philology and General Linguistics; University of Barcelona Institute for Complex Systems; Catalan Institute for Research and Advanced Studies & Laboratoire Dysco; Université Paris 8)

Keywords: language evolution; color lexicons; cross-cultural psychology; color perception; Himba people

Color vocabularies reflect remarkable diversity, notably in the number of color terms used. Such diversity has often been ascribed to differences in communicative needs. Conversely, color lexicons also share important common patterns, often attributed to shared perceptual systems among humans. However, several studies challenge the latter assumption. In this research, we examine the possibility that differences in color perception across cultures may contribute to shaping color lexicons. To explore this, we conducted a comparative analysis of color perception in two populations: the French and the Himba people. These two groups exhibit markedly different color lexicons, paralleled by exposure to distinct environmental conditions. Notably, Himba participants are exposed to significantly more UV radiation, a factor that may impact color perception (especially for blue colors) through its effects on the eye physiology.

This study employed a comprehensive battery of color-perception tasks designed to control for task reliability for cross-cultural comparison. After careful task selection, we analyzed the results from two computerized tests, focusing specifically on blue and red colors. The first task involved discriminating the direction of a flashing arrow, of which the contrast with the background color progressively decreased, allowing us to measure the Just Noticeable Difference (JND) threshold. In the second task, 12 squares arranged in a circular pattern were shown on screen, where one deviant square was presented in a different color. Participants' reaction time and accuracy were measured as they detected on which side of the screen the deviant square appeared. To minimize potential biases in inter-group comparisons, we controlled for various confounding variables, including factors related to patterns of color naming and other possible confounds associated with color perception.

Our findings reveal a direct effect of age, which interacts with population: color perception deteriorates more steeply with age in the Himba sample of participants than in the French sample. Interestingly, although we expected a more pronounced effect for blue than red colors, this age-related decline was similar across all colors. While increased UV exposure emerges as a likely contributing factor, we do not rule out the possibility that other factors, such as genetic or cultural differences between the two populations, may account for the stronger effect of age on color perception in the Himba sample. Even though the causal mechanisms at the root of these results require additional investigation, the group difference in color perception raises intriguing questions. Given the influence of perceptual space on color lexicon, we suggest that the variations in color perception we have observed between the French and Himba participants have contributed to shaping their respective color lexicons. Thus, while communicative need is an important factor in shaping color lexicon, perceptual structure may also serve an important dual role, contributing to both
commonalities and differences in color lexicons. This research advances our understanding of the intricate relationship between perception and language. Overall, this work suggests that language is deeply intertwined with its surroundings, highlighting the relevance of considering weak biases related to the socio-cultural system, the environment, or the biology of its speaker.

Acknowledgments: We thank Giorgio Vallortigara, without whom the trip to Namibia would not have been possible. We would also like to express our gratitude to Arash Sahraie for generously sharing the data from their paper with us. Additionally, we appreciate the invaluable support of Esther Boissin and Anna Blumenthal during the fieldworks. Our acknowledgements also go to our guides and translators, Aparicio Lopez, Fanny Kavari, Hilde Simon, and Cancy Luise, who played a pivotal role in this research. Last but not least, we strongly thank the Himba participants and the Namibian people in general for their warm welcome in Namibia, embracing our project with openness, benevolence, and generosity. This research was funded by a grant from the Institut Universitaire de France awarded to the last author (IUF-CAP-2020-0396). We also thank Labex Aslan for their scholarship Aslan AFE to compensate the French participants