In human language, Menzerath’s law states that ‘the larger the hole, the smaller its parts’. Thus, for example, longer words tend to be made up of shorter syllables and longer phrases tend to be made up of shorter words. The law is named after Paul Menzerath, a Slovak linguist whose ideas have been the seed for decades of research in quantitative linguistics. The law is enforced in a wide spectrum of languages, but its existence has never been proven in any other species. Now, an international team of researchers, led by Morgan Gustison, from the University of Michigan, and Stuart Semple, from the University of Roehampton, in collaboration with researcher Ramon Ferrer , from the laboratory of Relational Algorithmics, Complexity and Learning (LARCA) of the Polytechnic University of Catalonia (UPC), has verified the law in geladas,
A species where males produce long mobile phone number list sequences of several calls – up to 25 calls in total – consisting of six different types of calls. They analyzed 1,065 such vocal sequences (made up of 4,747 individual calls) that were recorded from 57 males living in the Sankaber area of the Simien Mountains National Park in Ethiopia. The UPC researcher Ramon Ferrer has been in charge of analyzing the data from the vocalizations of the geladas and the design of the mathematical model. According to Menzerath’s law, they found a negative relationship between the length of the sequence in number of calls and the average duration of the calls that make it up. The calls did not vary in length according to their position in the vocal sequence. What is surprising is that the length of the first calls in the sequence was closely related to how long the sequence was. In other words,
The sequences started with calls of the “right” length for the sequence: short sequences started with long calls, and long sequences started with short calls. The findings of this work, published in the Proceedings of the National Academy of Sciences (PNAS), not only reveal a basic pattern of the sequential structure shared by human and non-human communication but could also have profound implications for our understanding of biological systems in a broader sense. In addition to their analysis of the gelada sequences, the study authors also mathematically support the idea that Menzerath’s law reflects ‘compression’, a principle in the field of information theory related to minimizing the expected length of a code. Compression provides a way to improve the efficiency of an encoding system and is applied (to save space or memory.