Bilingualism caught in a net. A new approach to understanding the complexity of bilingual experience
The growing importance of research on bilingualism in psychology and neuroscience motivates the need for a unified approach to understanding and quantifying this phenomenon. This study aimed to establish the first psychometric model of bilingualism. To this end, we re-analyzed two datasets (N = 171 and N = 112) from Polish-English bilinguals who completed a battery of questionnaires and tasks probing language experience. We asked whether bilingualism is best described by the factor structure (generalizable dimensions of bilingualism that are potentially explained by a higher-order construct) or by the network structure (direct and low-level dependencies between language skills and language-use practices which leads to the emergence of bilingualism).The factor and network structures were established on one dataset and then validated on the other dataset in a fully confirmatory manner. The network model provided the best fit to the data. Further network analyses showed that some indices demonstrated relatively stronger connections within the network than others. Yet, there was no central index that would explain most of the variability in bilingual experience.The results imply that bilingualism should be conceptualized as an emergent network of low-level and idiosyncratic dependencies between diverse language skills, the history of language acquisition, and language-use practices. These dependencies can be reduced to neither a single universal quotient nor to some more general factors. Overall, an indisputable advantage of the network model over the factor approach indicates the great potential of network modeling to gain a more accurate description and understanding of complex cognitive phenomena.