Primate's Call Obeys Linguistic Law

This Primate's Calls Obey a Linguistic Law (+Podcast, ~2 min.)

Christopher Intagliata | April 21, 2016

The vocalizations of the gelada, a baboon relative, appear to follow a linguistic rule called Menzerath's law. Christopher Intagliata reports.
Communication on Twitter is artificially constrained: 140 characters per tweet, max. So it turns out the more words in a tweet, the shorter each word tends to be—at least according to one analysis. Sorta makes sense on Twitter: there's a limited amount of space to play with. But the weird thing is, that pattern—longer phrase, shorter words—also holds true in our everyday language too. It's called Menzerath's law. 

Gelad-Pavian. Source: https://en.wikipedia.org/wiki/Gelada

<more at http://www.scientificamerican.com/podcast/episode/this-primate-s-calls-obey-a-linguistic-law/; related articles and links: http://letstalkprimates.blogspot.com/ (What do geladas and humans have in common? Apparently, vocal patterns. April 19, 2016) and http://www.pnas.org/content/early/2016/04/13/1522072113.abstract (Gelada vocal sequences follow Menzerath’s linguistic law. Morgan L. Gustison, Stuart Semple, Ramon Ferrer-i-Cancho, and Thore J. Bergman. PNAS: Proceedings of the National Academy of Sciences of the United States of America. Early edition, doi: 10.1073/pnas.1522072113. PNAS April 18, 2016. [Abstract: Identifying universal principles underpinning diverse natural systems is a key goal of the life sciences. A powerful approach in addressing this goal has been to test whether patterns consistent with linguistic laws are found in nonhuman animals. Menzerath’s law is a linguistic law that states that, the larger the construct, the smaller the size of its constituents. Here, to our knowledge, we present the first evidence that Menzerath’s law holds in the vocal communication of a nonhuman species. We show that, in vocal sequences of wild male geladas (Theropithecus gelada), construct size (sequence size in number of calls) is negatively correlated with constituent size (duration of calls). Call duration does not vary significantly with position in the sequence, but call sequence composition does change with sequence size and most call types are abbreviated in larger sequences. We also find that intercall intervals follow the same relationship with sequence size as do calls. Finally, we provide formal mathematical support for the idea that Menzerath’s law reflects compression—the principle of minimizing the expected length of a code. Our findings suggest that a common principle underpins human and gelada vocal communication, highlighting the value of exploring the applicability of linguistic laws in vocal systems outside the realm of language.])>