Commentary: Culture mediates the effects of humidity on language

Does (the presence or complexity of) tone inversely correlate with dryness of climate? The authors (Everett et al.) suggest that the absence of ambient humidity in the air negatively correlates with the presence of (complex?) lexical tone, partly because of the effect that dry air has to increase the difficulty in achieving precise articulatory targets. There are two main problems with the argumentation used. 1. Conflating ‘tone’ with ‘pitch’ or ‘fundamental frequency’, and mistaking ‘complexity’ with a syllable domain for tone assignment; 2. conflating ‘dry climate’ with the absence of humidity. The authors are not guilty in an absolute sense of these problems, acknowledging that there are complications. Their reliance on pitch contrasts as a proxy for tonal category contrasts, and the use of air humidity rather than (easily available) climate information for the ranges of different languages means that the authors are dealing with ephemeral correlations between proxy features. In the next two sections, I will critique the use of tone primarily to refer to distinctions realised by pitch, and the use of humidity as a powerful explanatory for the existence of tone categories. The authors acknowledge that ‘many non-pitch phenomena are associated with the production of tone, including ancillary laryngealization and duration influences’, but go on to claim that ‘the heightened role of F0 (and therefore pitch) in languages with complex tone is evident in the fact that its fine-grained modulation is required on every or almost every syllable, in contrast to pitch accent languages’. First, this …