Large-scale migrations result in different languages and cultures getting in contact with each other. It happened so in the past, and continues happening so in the 21st century Europe. Jewish languages, such as Yiddish, Ladino, Judeo-Arabic or Judeo-Italian, represent eminent examples of such linguistic and cultural interactions, and they will serve as case studies in our project.The present project is composed of two parts. Language interaction, as exemplified by Yiddish and other Jewish languages, will be first measured using contemporary techniques in dialectometry. The Language and Culture Atlas of Ashkenazic Jewry (LCAAJ) will serve as the dataset for understanding how cultural and linguistic features have spread in Jewish communities across Europe, and how these features interact with the local non-Jewish cultures and languages.Second, the quantitative picture thus arrived at will be reproduced using computer simulations. These simulations will combine social network models with cognitive architectures. The social structure and historical change will be approached by a multi-agent version of the Iterative Learning Model. Then, each agent will be equipped with a linguistically motivated cognitive architecture representing the linguistic knowledge in each agent's mind. In particular, the project focuses on Optimality Theory (OT) and its variants (Harmonic Grammar, Maximum Entropy OT, Simulated Annealing for OT, etc.). These contemporary linguistic frameworks come with elaborated learning algorithms, and are implemented by the applicant's OTKit software package.Dialectometry, as well as computer simulations with cognitive models and social networks represent state-of-the-art techniques hardly applied to the study of Jewish languages. The applicant has acquired these techniques in the Netherlands and the United States, and he will transfer them to Hungary.