Climate, vocal folds, and tonal languages: Connecting the physiological and geographic dots

Abstract

We summarize a number of findings in laryngology demonstrating that perturbations of phonation, including increased jitter and shimmer, are associated with desiccated ambient air. We predict that, given the relative imprecision of vocal fold vibration in desiccated versus humid contexts, arid and cold ecologies should be less amenable, when contrasted to warm and humid ecologies, to the development of languages with phonemic tone, especially complex tone. This prediction is supported by data from two large independently coded databases representing 3,700+ languages. Languages with complex tonality have generally not developed in very cold or otherwise desiccated climates, in accordance with the physiologically based predictions. The predicted global geographic-linguistic association is shown to operate within continents, within major language families, and across language isolates. Our results offer evidence that human sound systems are influenced by environmental factors.climate | language | adaptation | tone A standard assumption in linguistics is that sound systems are immune to ecological effects (1). This presumption has been called into question by several recent studies providing evidence for a correlation between aspects of phonology (such as sonority) and climatic and geographic factors (such as temperature, plant cover, or terrain), as well as behaviors associated with such factors (2-9). Most recently, a correlation was uncovered between ejective sounds and regions of high elevation in a sample of nearly 600 languages (10). Although two plausible physiological motivations are offered in ref. 10 for the correlation between ejective use and reduced ambient air pressure, those explanations have yet to be supported by experimental evidence. The uncovered patterns could be epiphenomenal, and in general, the cross-linguistic statistical studies in question have not been buttressed by experimental support (11).In this study, we offer evidence for a negative correlation between linguistic tone and characteristic rates of desiccation in ambient air. In contradistinction to the aforementioned studies offering geographic/phonetic correlations, however, we suggest this correlation is predicted by extensive experimental research on the properties of the human larynx. This research, which has been conducted by numerous laryngologists over the last decade and a half, has not been previously tied to the distribution of the world's tonal languages. We submit that the research predicts that the relatively precise manipulation of the vocal folds associated with tone, especially complex tone, should be more difficult to achieve in arid climates-particularly very cold ones-when contrasted to warmer and more humid climates. We offer global, continental, and intralinguistic-family data consistent with the expected geographic/tonemic association. Our results cannot facilely be ascribed to well-known phylogenetic and areal relatedness. We conclude by suggesting that the most reasonable interpretation of the data is that the a...

Response: Climate and language: has the discourse shifted?

“…His logistic regressions suggest that the pattern holds independently in Eurasia, Africa, and North America. In Everett et al (2015) we observed that it also held in South America, and in fact the South American distribution is consistent given that languages with complex tone there occur in Amazonia. If the question is whether the pattern is simply consistent in these four macroregions, the answer is yes.…”

“…We begin with a simple point. The prediction of the account in Everett et al (2015) was that languages with complex tonality should be less likely to occur in the world's driest regions. This prediction was certainly borne out.…”

“…1 Progovac and Ratliff also see that Everett et al (2015) was meant to encourage further development of the theory and engagement with the evidence rather than provide absolute proof of a complete explanation. We agree wholeheartedly.…”

“…Relatedly, Moran is right that statistical work should be accompanied with the data and code for reproducibility. Therefore, we include in this publication the data and code required to reproduce the results from Everett et al (2015) (see also https://github.com/seannyD/Tone ClimateJoLE).…”

Linguistic Approaches in Teaching History of Science and Technology Courses through a Content Block on Cognitive Sciences

“…Similarly, large distances increase differences in languages and their phonemes. Tonal languages also correlate with geographical environments, and phonemes and sounds are ecologically adaptive (Everett, 2015). Taking into account the variety of factors that impact human linguistic capacity, it is possible to say that a combination of languages, genetic variations, and geographical conditions may fill in the patterns of our cognition and may confirm and complete the routes of human migrations through time.…”