Recent studies suggest that heterogeneous bilingual experiences implicate different executive functions (EF) in children. Using a latent profile analysis, we conducted a more nuanced investigation of multifaceted bilingual experiences. By concurrently considering numerous bilingual indicators – age of L1 and L2 acquisition, interactional contexts of verbal exchanges, L1 and L2 proficiency, balance of language use at home and school, and receptive vocabulary – we identified three latent profiles (subgroups): balanced dual-language, dominant single-language, and mixed-interaction. We found that the balanced dual-language and dominant single-language profiles predicted significantly better switching than the mixed-interaction profile. However, no profile differences were found in working memory, prepotent response inhibition, or inhibitory control. These results held true when multiple covariates (age, sex, household income, and nonverbal intelligence) were controlled for. Using a person-centered approach, our study underscores that disparate bilingual experiences asymmetrically predict the shifting facet of EF during early childhood.

This commentary makes the argument that the child-internal and child-external sources of individual differences in bilingual development are much the same as the sources of individual differences in monolingual development. It makes the further argument that the operation of the child-external influences results in differences between monolingual and bilingual development in the rate and sometimes in the outcome of language acquisition. An argument is made for the scientific and practical value of understanding the differences between monolingual and bilingual development, and future directions for research are suggested.

Bilingualism as it occurs in current societies is a complex, multidimensional and dynamic phenomenon, calling for new approaches to capture this concept. This study shows the feasibility of a person-centred approach by combining measures of the use of and proficiency in the first and second language from 110 young Turkish–Dutch children at two measurement waves, using two existing datasets. Latent Profile Analysis revealed four profiles, equivalent at age four and six: 1) Dominant L1 use, relatively low L1 and L2 proficiency, 2) Dual L1 and L2 use, around average L1 and L2 proficiency, 3) Dominant L1 use, relatively high L1 and L2 proficiency and 4) Dominant L2 use, relatively high L2 proficiency. Latent Transition Analysis indicated that children changed in profiles over time. Regression analyses showed that profiles were differently related to the family's socioeconomic status and children's nonverbal intelligence at age four. No relations were found at age six.