Language is universally used by all human groups, but this universality comes with very high levels of variation at all levels across the 7,000 or so languages (Evans & Levinson, 2009). For example, linguistic differences between Japanese and English result in a ratio of 1:11 in their number of distinct syllables, with consequently large variation in their Shannonian information per syllable. Recent work suggests that linguistic diversity is due not only to language-internal processes of change (Campbell, 2004), but is also influenced by external factors such as climate (Everett, Blasí, & Roberts, 2016), population genetics (Dediu & Ladd, 2007), socio-demography (Lupyan & Dale, 2016) etc. This reinforces the view that, on timescales spanning generations, languages locally adapt to specific physico-bio-cultural niches, further increasing linguistic diversity (Lupyan & Dale, 2016, Christiansen & Chater, 2008)
During the talk, we will show, using quantitative methods applied to a large cross-linguistic corpus, that the interplay between language-specific structural properties (as reflected by the amount of information per syllable) and speaker-level language production and processing (as reflected by speech rate) lead languages to gravitate around an optimal information rate of about 40bits/second. We will argue that this result highlights the intimate feedback loops between languages and their speakers, and supports a view of human language as the product of a niche construction process involving biology, environment and culture.
|