Progressive and regressive transfer in third language acquisition and development: An up-to-date review

This contribution provides an up-to-date classification of the most important theoretical models accounting for Third Language Acquisition (TLA). Also, it aims to enrich the gamut of studies on cross-linguistic influence (CLI) by adding up critical observations and interpretations on recent research on both progressive and regressive transfer in TLA and development. In this work, we also try to cast light on potential lines for future research, by placing emphasis on some areas of TLA studies which have been so far understudied. First, we discuss the issues in giving a univocal definition for the process of TLA, and untangle the role of linguistic and extralinguistic factors in CLI between a native language (L1), a second language (L2) and a third language (L3). Next, we sketch different scenarios for what concerns potential sources of progressive transfer: absolute/full transfer from L1, as argued by the “Developmentally Moderated Transfer Hypothesis”; privileged transfer from L2, as postulated by the “Second Language Status Factor”; transfer from any previously acquired language, as maintained by the “Cumulative-enhancement Model” and the “Typological Primacy Model”; property-by-property transfer, as supported by the “Parasitic Model”, the “Linguistic Proximity Model” and the “Scalpel Model”. Then, we present the only theoretical framework currently present in literature describing regressive transfer in TLA, i.e. the “Phonological Permeability Hypothesis”. Finally, we suggest that sociolinguistic, socioeconomic and socioeducational factors should gain more relevance in TLA studies, and that a “Dynamic Model” may have a crucial role in interpreting the intersection of all these multifaceted aspects.