Language dynamics is a rapidly growing field that focuses on all processes related to the evolution, emergence, change, competition and extinction of languages. One of the major outcomes from this field of research is that language can be viewed as a complex adaptive dynamical system that evolves through the process of self-organization and self-regulation. According to this viewpoint, a community of language users can be seen as a dynamical system that collectively solves the problem of developing a shared communication framework through the back-and-forth signaling between the participating individuals.
Our group is interested in the interaction of the cognitive and socio-cultural factors that play a key role in language dynamics with a special focus on how a population develops a shared set of names (Naming Game), categories (Category Game), or rules (Rule Dynamics) from scratch. The basic framework is grounded in theories of Language Games, but frequently borrows concepts and methods from the areas of statistical physics and complex systems science. These areas have proven to be extremely powerful in providing various quantitative insights into language emergence and evolution.
Topics
Rule DynamicsCategory GameNaming GameBibliography
2016 |
Tria, Francesca; Loreto, Vittorio; Servedio, Vito; Salikoko, Mufwene Modeling The Emergence Of Creole Languages (Inproceeding) Roberts,; Cuskley,; McCrohon,; Barceló-Coblijn,; Fehér,; Verhoef, (Ed.): The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11), 2016. @inproceedings{evolang11_89, title = {Modeling The Emergence Of Creole Languages}, author = { Francesca Tria and Vittorio Loreto and Vito Servedio and S. Mufwene Salikoko}, editor = {S.G. Roberts and C. Cuskley and L. McCrohon and L. Barceló-Coblijn and O. Fehér and T. Verhoef}, url = {http://evolang.org/neworleans/papers/89.html}, year = {2016}, date = {2016-01-01}, booktitle = {The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11)}, abstract = {Creole languages offer an invaluable opportunity to study the processes leading to the emergence and evolution of Language, thanks to the short - typically a few generations - and reasonably well defined time-scales involved in their emergence. Another well-known case of a very fast emergence of a Language, though referring to a much smaller population size and different ecological conditions, is that of the Nicaraguan Sign Language. What these two phenomena have in common is that in both cases what is emerging is a contact language, i.e., a language born out of the non-trivial interaction of two (or more) parent languages. This is a typical case of what is known in biology as horizontal transmission. In many well-documented cases, creoles emerged in large segregated sugarcane or rice plantations on which the slave labourers were the overwhelming majority. Lacking a common substrate language, slaves were naturally brought to shift to the economically and politically dominant European language (often referred to as the lexifier) to bootstrap an effective communication system among themselves. Here, we focus on the emergence of creole languages originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean, where detailed census data are available. Those for several States of USA can be found at http://www.census.gov/history, while for Central America and the Caribbean can be found at http://www.jamaicanfamilysearch.com/Samples/1790al11.htm. Without entering in the details of the creole formation at a fine-grained linguistic level, we aim at uncovering some of the general mechanisms that determine the emergence of contact languages, and that successfully apply to the case of creole formation.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Creole languages offer an invaluable opportunity to study the processes leading to the emergence and evolution of Language, thanks to the short - typically a few generations - and reasonably well defined time-scales involved in their emergence. Another well-known case of a very fast emergence of a Language, though referring to a much smaller population size and different ecological conditions, is that of the Nicaraguan Sign Language. What these two phenomena have in common is that in both cases what is emerging is a contact language, i.e., a language born out of the non-trivial interaction of two (or more) parent languages. This is a typical case of what is known in biology as horizontal transmission. In many well-documented cases, creoles emerged in large segregated sugarcane or rice plantations on which the slave labourers were the overwhelming majority. Lacking a common substrate language, slaves were naturally brought to shift to the economically and politically dominant European language (often referred to as the lexifier) to bootstrap an effective communication system among themselves. Here, we focus on the emergence of creole languages originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean, where detailed census data are available. Those for several States of USA can be found at http://www.census.gov/history, while for Central America and the Caribbean can be found at http://www.jamaicanfamilysearch.com/Samples/1790al11.htm. Without entering in the details of the creole formation at a fine-grained linguistic level, we aim at uncovering some of the general mechanisms that determine the emergence of contact languages, and that successfully apply to the case of creole formation. |
Cuskley, Christine; Loreto, Vittorio The Emergence Of Rules And Exceptions In A Population Of Interacting Agents (Inproceeding) Roberts,; Cuskley,; McCrohon,; Barceló-Coblijn,; Fehér,; Verhoef, (Ed.): The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11), 2016. @inproceedings{evolang11_119, title = {The Emergence Of Rules And Exceptions In A Population Of Interacting Agents}, author = { Christine Cuskley and Vittorio Loreto}, editor = {S.G. Roberts and C. Cuskley and L. McCrohon and L. Barceló-Coblijn and O. Fehér and T. Verhoef}, url = {http://evolang.org/neworleans/papers/119.html}, year = {2016}, date = {2016-01-01}, booktitle = {The Evolution of Language: Proceedings of the 11th International Conference (EVOLANGX11)}, abstract = {Rules are an efficient feature of natural languages which allow speakers to use a finite set of instructions to generate a virtually infinite set of utterances. Yet, for many regular rules, there are irregular exceptions. There has been lively debate in cognitive science about how individual learners acquire rules and exceptions; for example, how they learn the past tense of preach is preached, but for teach it is taught. In this paper, we take a different perspective, examining the dynamics of regularity and irregularity across a population of interacting agents to investigate how inflectional rules are applied to verbs. We show that in the absence of biases towards either regularity or irregularity, the outcome is determined by the initial condition, irrespective of the frequency of usage of the given lemma. On the other hand, in presence of biases, rule systems exhibit frequency dependent patterns in regularity reminiscent of patterns in natural language corpora. We examine the case where individuals are biased towards linguistic regularity in two ways: either as child learners, or through a memory constraint wherein irregular forms can only be remembered by an individual agent for a finite time period. We provide theoretical arguments for the prediction of a critical frequency below which irregularity cannot persist in terms of the duration of the finite time period which constrains agent memory.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Rules are an efficient feature of natural languages which allow speakers to use a finite set of instructions to generate a virtually infinite set of utterances. Yet, for many regular rules, there are irregular exceptions. There has been lively debate in cognitive science about how individual learners acquire rules and exceptions; for example, how they learn the past tense of preach is preached, but for teach it is taught. In this paper, we take a different perspective, examining the dynamics of regularity and irregularity across a population of interacting agents to investigate how inflectional rules are applied to verbs. We show that in the absence of biases towards either regularity or irregularity, the outcome is determined by the initial condition, irrespective of the frequency of usage of the given lemma. On the other hand, in presence of biases, rule systems exhibit frequency dependent patterns in regularity reminiscent of patterns in natural language corpora. We examine the case where individuals are biased towards linguistic regularity in two ways: either as child learners, or through a memory constraint wherein irregular forms can only be remembered by an individual agent for a finite time period. We provide theoretical arguments for the prediction of a critical frequency below which irregularity cannot persist in terms of the duration of the finite time period which constrains agent memory. |
2015 |
Tria, Francesca; Servedio, Vito; Mufwene, Salikoko; Loreto, Vittorio Modeling the Emergence of Contact Languages (Journal Article) PLoS ONE, 10 (4), pp. e0120771, 2015. @article{10.1371/journal.pone.0120771, title = {Modeling the Emergence of Contact Languages}, author = {Francesca Tria and Vito D.P. Servedio and Salikoko Mufwene and Vittorio Loreto}, url = {http://dx.doi.org/10.1371%2Fjournal.pone.0120771}, doi = {10.1371/journal.pone.0120771}, year = {2015}, date = {2015-01-01}, journal = {PLoS ONE}, volume = {10}, number = {4}, pages = {e0120771}, publisher = {Public Library of Science}, abstract = { Contact languages are born out of the non-trivial interaction of two (or more) parent languages. Nowadays, the enhanced possibility of mobility and communication allows for a strong mixing of languages and cultures, thus raising the issue of whether there are any pure languages or cultures that are unaffected by contact with others. As with bacteria or viruses in biological evolution, the evolution of languages is marked by horizontal transmission; but to date no reliable quantitative tools to investigate these phenomena have been available. An interesting and well documented example of contact language is the emergence of creole languages, which originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean. Here, we focus on the emergence of creole languages to demonstrate a dynamical process that mimics the process of creole formation in American and Caribbean plantation ecologies. Inspired by the Naming Game (NG), our modeling scheme incorporates demographic information about the colonial population in the framework of a non-trivial interaction network including three populations: Europeans, Mulattos/Creoles, and Bozal slaves. We show how this sole information makes it possible to discriminate territories that produced modern creoles from those that did not, with a surprising accuracy. The generality of our approach provides valuable insights for further studies on the emergence of languages in contact ecologies as well as to test specific hypotheses about the peopling and the population structures of the relevant territories. We submit that these tools could be relevant to addressing problems related to contact phenomena in many cultural domains: e.g., emergence of dialects, language competition and hybridization, globalization phenomena. },keywords = {}, pubstate = {published}, tppubtype = {article} } <p>Contact languages are born out of the non-trivial interaction of two (or more) parent languages. Nowadays, the enhanced possibility of mobility and communication allows for a strong mixing of languages and cultures, thus raising the issue of whether there are any pure languages or cultures that are unaffected by contact with others. As with bacteria or viruses in biological evolution, the evolution of languages is marked by horizontal transmission; but to date no reliable quantitative tools to investigate these phenomena have been available. An interesting and well documented example of contact language is the emergence of creole languages, which originated in the contacts of European colonists and slaves during the 17th and 18th centuries in exogenous plantation colonies of especially the Atlantic and Indian Ocean. Here, we focus on the emergence of creole languages to demonstrate a dynamical process that mimics the process of creole formation in American and Caribbean plantation ecologies. Inspired by the Naming Game (NG), our modeling scheme incorporates demographic information about the colonial population in the framework of a non-trivial interaction network including three populations: Europeans, Mulattos/Creoles, and Bozal slaves. We show how this sole information makes it possible to discriminate territories that produced modern creoles from those that did not, with a surprising accuracy. The generality of our approach provides valuable insights for further studies on the emergence of languages in contact ecologies as well as to test specific hypotheses about the peopling and the population structures of the relevant territories. We submit that these tools could be relevant to addressing problems related to contact phenomena in many cultural domains: e.g., emergence of dialects, language competition and hybridization, globalization phenomena.</p> |
Cuskley, Christine; Colaiori, Francesca; Castellano, Claudio; Loreto, Vittorio; Pugliese, Martina; Tria, Francesca The adoption of linguistic rules in native and non-native speakers: Evidence from a Wug task (Journal Article) Journal of Memory and Language, 84 , pp. 205 - 223, 2015, ISSN: 0749-596X. @article{Cuskley2015205, title = {The adoption of linguistic rules in native and non-native speakers: Evidence from a Wug task}, author = {Christine Cuskley and Francesca Colaiori and Claudio Castellano and Vittorio Loreto and Martina Pugliese and Francesca Tria}, url = {http://www.sciencedirect.com/science/article/pii/S0749596X15000790}, doi = {http://dx.doi.org/10.1016/j.jml.2015.06.005}, issn = {0749-596X}, year = {2015}, date = {2015-01-01}, journal = {Journal of Memory and Language}, volume = {84}, pages = {205 - 223}, abstract = {Several recent theories have suggested that an increase in the number of non-native speakers in a language can lead to changes in morphological rules. We examine this experimentally by contrasting the performance of native and non-native English speakers in a simple Wug-task, showing that non-native speakers are significantly more likely to provide non -ed (i.e., irregular) past-tense forms for novel verbs than native speakers. Both groups are sensitive to sound similarities between new words and existing words (i.e., are more likely to provide irregular forms for novel words which sound similar to existing irregulars). Among both natives and non-natives, irregularizations are non-random; that is, rather than presenting as truly irregular inflectional strategies, they follow identifiable sub-rules present in the highly frequent set of irregular English verbs. Our results shed new light on how native and non-native learners can affect language structure.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Several recent theories have suggested that an increase in the number of non-native speakers in a language can lead to changes in morphological rules. We examine this experimentally by contrasting the performance of native and non-native English speakers in a simple Wug-task, showing that non-native speakers are significantly more likely to provide non -ed (i.e., irregular) past-tense forms for novel verbs than native speakers. Both groups are sensitive to sound similarities between new words and existing words (i.e., are more likely to provide irregular forms for novel words which sound similar to existing irregulars). Among both natives and non-natives, irregularizations are non-random; that is, rather than presenting as truly irregular inflectional strategies, they follow identifiable sub-rules present in the highly frequent set of irregular English verbs. Our results shed new light on how native and non-native learners can affect language structure. |
Colaiori, Francesca; Castellano, Claudio; Cuskley, Christine; Loreto, Vittorio; Pugliese, Martina; Tria, Francesca General three-state model with biased population replacement: Analytical solution and application to language dynamics (Journal Article) Phys. Rev. E, 91 , pp. 012808, 2015. @article{PhysRevE.91.012808b, title = {General three-state model with biased population replacement: Analytical solution and application to language dynamics}, author = { Francesca Colaiori and Claudio Castellano and Christine F. Cuskley and Vittorio Loreto and Martina Pugliese and Francesca Tria}, url = {http://link.aps.org/doi/10.1103/PhysRevE.91.012808}, doi = {10.1103/PhysRevE.91.012808}, year = {2015}, date = {2015-01-01}, journal = {Phys. Rev. E}, volume = {91}, pages = {012808}, publisher = {American Physical Society}, abstract = {Empirical evidence shows that the rate of irregular usage of English verbs exhibits discontinuity as a function of their frequency: the most frequent verbs tend to be totally irregular. We aim to qualitatively understand the origin of this feature by studying simple agent-based models of language dynamics, where each agent adopts an inflectional state for a verb and may change it upon interaction with other agents. At the same time, agents are replaced at some rate by new agents adopting the regular form. In models with only two inflectional states (regular and irregular), we observe that either all verbs regularise irrespective of their frequency, or a continuous transition occurs between a low-frequency state, where the lemma becomes fully regular, and a high-frequency one, where both forms coexist. Introducing a third (mixed) state, wherein agents may use either form, we find that a third, qualitatively different behaviour may emerge, namely, a discontinuous transition in frequency. We introduce and solve analytically a very general class of three-state models that allows us to fully understand these behaviours in a unified framework. Realistic sets of interaction rules, including the well-known naming game (NG) model, result in a discontinuous transition, in agreement with recent empirical findings. We also point out that the distinction between speaker and hearer in the interaction has no effect on the collective behaviour. The results for the general three-state model, although discussed in terms of language dynamics, are widely applicable.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Empirical evidence shows that the rate of irregular usage of English verbs exhibits discontinuity as a function of their frequency: the most frequent verbs tend to be totally irregular. We aim to qualitatively understand the origin of this feature by studying simple agent-based models of language dynamics, where each agent adopts an inflectional state for a verb and may change it upon interaction with other agents. At the same time, agents are replaced at some rate by new agents adopting the regular form. In models with only two inflectional states (regular and irregular), we observe that either all verbs regularise irrespective of their frequency, or a continuous transition occurs between a low-frequency state, where the lemma becomes fully regular, and a high-frequency one, where both forms coexist. Introducing a third (mixed) state, wherein agents may use either form, we find that a third, qualitatively different behaviour may emerge, namely, a discontinuous transition in frequency. We introduce and solve analytically a very general class of three-state models that allows us to fully understand these behaviours in a unified framework. Realistic sets of interaction rules, including the well-known naming game (NG) model, result in a discontinuous transition, in agreement with recent empirical findings. We also point out that the distinction between speaker and hearer in the interaction has no effect on the collective behaviour. The results for the general three-state model, although discussed in terms of language dynamics, are widely applicable. |