Solving Transfer Puzzles: Multi-Factor Explanations

Abstract

This article proposes a multi-factor model of second language learning and bilingualism, CASP (an acronym for Complex Adaptive System Principles), which can help solve some puzzles in language transfer, involving when it occurs and when it does not. The key goal is to try to move the field beyond discussions that are focused on just one or two of the many factors of relevance (e.g., typological similarity vs. distance and levels of proficiency). This study gives a critical and comparative discussion of previous research on word order variation and null versus overt subjects in grammars, as carried out within two different theoretical frameworks, namely the Competition Model and Processability Theory. We explain why conflicting results and explanations have come out of these camps. We use examples from CASP-based research and from recent experimental studies involving different types of bilingual speakers, as well as findings from previous studies that used a variety of empirical methodologies (e.g., fieldwork and classroom research) and theoretical approaches. The CASP model accounts for when and why transfer occurs, and crucially, it can explain when and why it does not occur, in many of the bilingual outputs discussed in the field, which has often been elusive to previous research. We offer both theoretical and empirical insights that help us solve some of the perennial puzzles in bilingualism and pave the way towards capturing different bilingual outputs of different types of bilinguals who learn and use their languages under different circumstances. We explain why any model of bilingualism must be a multi-factor one, incorporating typological factors, internal factors (such as age, proficiency and dominance) and external factors (i.e., specific interactional circumstances; e.g., single vs. dual language condition; formal vs. informal) and their varying collaborative and competing relationships.