To date, little is known about the conditions under which successful dual language learning in Europe’s largely monolingual societies takes place, and which variables mediate and moderate multilingual development in this context. Within a large interdisciplinary project, a consortium of researchers investigates this complex developmental phenomenon. The team includes experts working in the field of linguistics, education, developmental and cognitive psychological science located in Switzerland and Germany. The project examines single and dual language learning three- to five-year-old children longitudinally across a time span of 2.5 years. Single language learners grow up acquiring either the societal language of German or French. Dual language learners obtain either Turkish or Italian within the family-context, i.e. as their home language, and one of the mentioned societal languages, in addition. The research project aims to establish a unified model of single and dual language learning and its reciprocal interrelations with important child-internal and child-external factors.

The here proposed symposium presents a platform to communicate the first set of scientific findings obtained in this comprehensive research project. Four contributions (one from each participating research site) highlight the role of cognitive and socio-emotional skills that most presumable represent driving motors to dual language learning.

Dual language learners are assumed to develop strong executive functioning and metacognitive skills. However, it is still completely unknown how such advantages relate to dual language learners’ two languages and in what manner effects impact socioemotional skills and their development.

The individual contributions attempt to provide initial answers to these important research questions:

1. The construction of cross-linguistically fair oral language scales for single and dual language learning preschoolers

2. The unique relevance of gesture recognition for dual language learning

3. Social-emotional competencies of preschool-age single and dual language learners and their social context

4. Differential effects of single and dual language acquisition on domestic and academic word knowledge  

References are not included in the abstract