The integration of non-native populations into society, and especially into the workforce, is dependent upon the learning of a new language, and mostly, the acquisition of functional literacy. Indeed, a long-term objective of the EU commission is that every citizen achieves literacy in at least two foreign languages. How do proficient readers in one language learn a novel writing system and achieve literacy in a second or third language? What are the regularities that they perceive and learn? What are the main neuro-cognitive mechanisms governing this learning of statistical regularities? Why is this task relatively easy for some but not for others? These intriguing and complex questions were the focus of L2STAT. The aim of the research project was to produce and test a neurobiological theory of assimilating novel writing systems by the brain, a theory that could accommodate in principle any writing system, and has, therefore, wide explanatory power. L2STAT was an interdisciplinary project that employed in parallel advanced methods from computational linguistics and machine learning, the use of biologically-inspired computational models, the development of psychometrically reliable behavioral tests of individuals’ capacities to extract regularities, a search for reliable neurobiological signatures of detecting regularities in the human brain, and extensive behavioral experimentation in four sites (Israel, Spain, Taiwan, USA) to examine the inter-relation of statistical learning ability and reading proficiency in different languages. Overall, the project offered for the first time a theoretical framework for assessing individual differences in statistical learning, and outlined their relations to reading (dis)abilities. It elucidated the componential structure of statistical learning performance, tracing their relation to literacy acquisition in a writing system.