Physicists and mathematicians study the evolution of language with language norm change

The study was carried out by the researchers from the Department of Condensed Matter Physics and the Institute of Complex Systems of the UB (UBICS) Albert Díaz-Guilera and Roberta Amato, together with the researcher Andrea Baronchelli, lecturer at the City, University of London, and Lucas Lacasa, from the Queen Mary University of London.

“In this study, we identified different patterns to adopt language norm change depending on whether it is a spontaneous change or it follows changes that were suggested by an institution”, says Albert Díaz-Guilera, director of UBICS. “However, we present a simple mathematic model that reproduces all the empirical observations and enables us to improve our knowledge on the language cultural evolution and the collective behaviour regarding some proposals”, he concludes.

Three time scales

In 2815 the Royal Spanish Academy (RAE) introduced a rule with which certain words that were spelled with q had to be written with c, such as quadro-cuadro, quando-cuando and quotidiano-cuotidiano. Another change they analized is the one from 1884, with which some words had to be stressed (guion-guión) or had double r (virey-virrey). “In these cases, there is an immediate change, and after the same year, the change the RAE suggests is generally used”.

In data analysis, the authors identified three different behaviours depending on the origins of the change. The examples from RAE lie within the first type, where the change is given by a formal institution.

The second type is the case of an informal institution, such as new dictionaries published in the United States during the 19th and 20th centuries. Roberta Amato, PhD student at the UB and co-author of the study, notes they analysed “millions of books digitized by Google and considered cases such as the emergence of the North American English spelling (for instance, changes from behaviour to behavior, or analyse to analyze)”.
 
The last group belongs to spontaneous processes that take place outside any kind of institution and come up when a number of users chooses to use the new convention instead of the old one. This is the case, for instance, of the two subjunctives in Spanish: anduviera and anduviese.

Another case they analysed, and which is under debate, is the use of the stress in the adverb solo, which used to be stressed. In this case, a recent norm removed it completely, as seen in this sheet.

Temporary curves in each of the studied cases allow researchers identifying three time scales. The study was carried out with Google Ngram Corpora, a database with five million digitized books with the collaboration of thousands of libraries from around the world, and which offers a barometer on the lexical change.

“The study has many implications”, notes Andrea Baronchelli, coordinator of the study. “Language is a wide field to test change theories thanks to digitized texts, but the mechanisms we identified can also be applied to other fields. Several parties, from governments to private organizations, try to influence conventional behaviours and beliefs, and we know social networks try to speed up the process of collective behaviour change”, says the expert. According to the researcher, understanding how social norms change, and the signs this change leaves in data, will lead to a better understanding of our society and help shape interventions aimed at contrasting undesired effects”.

Article reference:
Roberta Amato, Lucas Lacasa, Albert Díaz-Guilera i Andrea Baronchelli. "The dynamics of norm change in the cultural evolution of language". Proceedings of the National Academy of Sciences (PNAS), August, 2018. DOI: 10.1073/pnas.1721059115