Linguistic Diversity Through Data
Total Page：16
File Type：pdf, Size：1020Kb
Linguistic Diversity Through Data ACKNOWLEDGEMENTS A large number of people and institutions supported or contributed in some way to my doctoral research, which reflects both the increas- ingly social nature of science and the characteristics of my own re- search, permanently in need of specialists in different aspects of the study of language. Naturally, here I restrict my acknowledgements to the period 2012-2015 (otherwise the acknowledgement list would be too long!) First of all, the Max Planck Gesellschaft has given me unmatched conditions of research, mobility and intellectual freedom that I have never experienced before or after in any of the many universities and research institutions I have visited. I spent my time as a student be- tween four Max Planck Institutes (Mathematics in the Sciences, Evolu- tionary Anthropology, Psycholinguistics and Science of Human His- tory) and I have visited or taken courses in another two (Cognitive Neuroscience and Complex Systems) and, in spite of necessary id- iosyncratic differences among them, the climate of high-end research and a preference for cutting-edge science is one and the same. Naturally, the MPI for Mathematics in the Science takes promi- nence over the others, if not only due to their bold decision of ac- cepting me as a doctoral student even after I confessed that I wanted to do research on language. Part of my puzzlement disappeared af- ter I met Jurgen¨ Jost. In the first conversation that we had he brought to the discussion themes and research on neurosciences, linguistics, computer sciences, human history, economy, physics and mathemat- ics. This amplitude of interests, I learned, was also reflected in his own scientific work: from genetics to geometry and the structure of meaning, Jurgen¨ has published about all the possible objects of scien- tific inquiry. No surprise, then, that the accepted my plural interests as a natural thing, as a given in other fellow scientists. Even more, he always deposited his trust in my decisions, which varied between enrolling a course in primatology, attending a school in cognitive lin- guistics and taking a course on information geometry for biology. Something similar I could say about Peter Stadler. I guess many times we looked like Aristotle’s pupils, walking around Leipzig while talking about how to set up a particularly tricky test or how to navi- gate the complex world of scientific politics. There is an anecdote that illustrates transparently his integrity very well. Within the first weeks of my arrival, he told me there was certain algorithm that “needed to be done”. I understood the allusion but I was not really thrilled about the task. After a week of hesitations, I went to his office and told him that I did not want to do it. He asked me “then what would you 3 do?”. Since then he has always been supportive of my interests and my career choices. He has been ideal as a supervisor, hands down. Apart from my other colleagues at the MPI MIS (specially, Felix, Gerardo, Wiktor and Yuri) and my friends at Bioinf (in particular Bruno, Tomas and Lorena) I also wanted to highlight how much I owe to Antje Vandenberg, who helped so many times with the German bureaucracy — it takes ages to make understand someone from South America how important is to fill forms and keep track of papers! The Department of Linguistics at the MPI for Evolutionary Anthro- pology turned out to be my second (and for some periods, my first) home in Leipzig. Bernard Comrie considered that my initial vague interests in language were sufficient for letting me hang around in the department — sometimes in the library, some other times in the common area. It was Soren¨ Wichmann, however, who took pity of me and offered me a space in his office — and not only that: he has cooked for me in more than one occasion. Many other people at the EVA gave color to my days spent there. Susanne Michaelis and Martin Haspelmath have been extremely nice and understand- ing with my first steps into the study of creoles. Several conversations with Paul Heggarty, Hans-Jorg¨ Bibiko, Heriberto Avelino and Harald Hammarstrom¨ spiced up my interest on several aspects of language, usually with a Weissbier at sight. I received quite a lot of support from other scholars during the early stages of my career, either by means of direct advise (promi- nently from Morten Christiansen) or by being invited to give a talk (by Gerhard Jaeger and Balthasar Bickel.) A very special spot is oc- cupied by Michael Dunn, who hosted me for almost six months at his group (“Evolutionary processes in language and culture”) at the Max Planck Institute for Psycholinguistics. It was an unique chance for me to scrutiny the daily schedule of a busy and intelligent scholar - before (and during) that period I would work at odd hours (say, from 9 pm to 6 am) and have an open-ended working schedule (what paper/project got my attention today?). We never got to write anything together, but I can’t underestimate how important were those months for my first steps as a functional scientist. In Nijmegen I met lots of in- teresting people, and some of them became quite rapidly my friends: Jeremy, Hedvig, Caroline and Sean.´ I spent a brief but quite productive period at the Centre for Lan- guage Evolution hosted at the University of Edinburgh. My thanks go primarily to Monica´ Tamariz and Simon Kirby who made that possible, and to the (large) Edinburgh crowd that interacted with me those days. Interestingly, that visit produced in my brain the unlikely association between haggis and language evolution experiments. I finished my period as a PhD student writing this thesis at the Max Planck Institute for the Science of Human History. This was possible thanks to Russell Gray, who since then has been both a mentor and 4 a friend to me (plus one of the few people from which you can learn about fine cuisine and wines and the theory of evolution in the same meeting.) My non-native English was smoothed by the amazing R. Schikowski, J. Mansfield and N. Uomini. All remaining mistakes are mine. Stefany, who underwent the same process of exile out of South America, has been the single most important person in my life in the last seven years. We coped with the same issues and hoped for a better future together. To my friends and family in Argentina (who are way too many to enumerate - my mom alone has 7 siblings!): gracias por el aguante. Sorry for not being there at the many birthdays, parties, asados, trips, sad moments, visits to the doctor, etc. that I missed because of this. To Stefany and them: I owe you much more than this degree. I do not write anymore because this is supposed to be a scholarly piece that celebrates hard work and intellectual achievement and not yet another instance where I surrender to my genes poisoned with tango and melancholy. 5 CONTENTS i introduction 9 1languages, data, and language data 11 1.1 Linguistic diversity (or not) 11 1.2 A short biographical motivation 14 1.3 The rise of the science of data 16 1.4 Doing science with linguistic data 19 1.5 A parallel effort 20 1.6 Two challenges of language data 22 1.6.1 On comparing language structures 22 1.6.2 On comparing languages 23 1.7 Structure of the thesis 26 1.8 Scientific output associated with this thesis 28 1.8.1 Peer-reviewed journals 28 1.8.2 Peer-reviewed conference presentations 29 ii unraveling unity in the world’slanguages 31 2dependenciesinwordorderpatterns 33 2.1 Combinatorics with words 33 2.2 The place of the subject, the object and the verb 34 2.3 The system of word orders 38 2.4 Word order correlations: facts, chance or statistical chimera? 40 2.5 Materials 43 2.6 The inference of dependencies 43 2.6.1 Directed Acyclic Graphs 43 2.6.2 From observational data to causal graphs 47 2.6.3 Results 50 2.7 Word order archetypes 55 2.7.1 Higher-order dependencies 55 2.7.2 Latent class modelling 57 2.7.3 Determining the number of classes 58 2.8 Conclusion 62 3non-arbitrary sound-meaning associations 65 3.1 Introduction 65 3.2 Testing associations on a global scale 66 3.3 Detecting sound-meaning associations 69 3.4 Strong worldwide associations 73 3.5 Origins and nature of the associations 78 3.6 Conclusion 83 iii explaining diversity in the world’slanguages 87 4creolesasatypologicalgroup 89 7 CONTENTS 4.1 Extreme contact languages 89 4.2 Origins of creoles 90 4.3 A statistical turn 94 4.4 Caveats for the testing of the creole profile 96 4.5 Exploratory analyses and ancestry-related features 97 4.5.1 Data 97 4.5.2 Exploratory analysis 98 4.6 Probabilistic profile classification 104 4.6.1 Random forests 104 4.6.2 Results 107 4.6.3 Variable importance 108 4.6.4 Results 109 4.7 Prototype profile classification 110 4.7.1 Associations rule mining 110 4.7.2 Results 113 4.8 Misclassification patterns 113 4.9 Conclusions 119 5ecologicalpressuresonspeechsounds 121 5.1 Human behaviour is flexible 121 5.2 The world-wide distribution of speech sounds 122 5.2.1 Results 123 5.3 The acoustic adaptation hypothesis 125 5.3.1 A stringer test of the AAH 126 5.3.2 Results 127 5.4 Tones and humidity 129 5.4.1 Vocal folds hydration 129 5.4.2 Results 130 5.5 Conclusions 132 iv general conclusion 135 6aneutralapproachtolanguage 137 8 Part I INTRODUCTION 1 LANGUAGES, DATA, AND LANGUAGE DATA 1.1 linguistic diversity (or not) Current estimates of the number of languages spoken in the world vary between 6000 to 8000, divided in over 300 groups that derive from a common ancestor, in some cases going back as far as the end of the Neolithic [102, 137].