Cognates are advantaged over non-cognates in early bilingual expressive vocabulary development.

Bilinguals need to learn two words for most concepts. These words are called translation equivalents, and those that also sound similar (e.g., banana-banane) are called cognates. Research has consistently shown that children and adults process and name cognates more easily than non-cognates. The present study explored if there is such an advantage for cognate production in bilinguals' early vocabulary development. Longitudinal expressive vocabulary data were collected from 47 English-French bilinguals starting at 16-20 months up to 27 months (a total of 219 monthly administrations in both English and French). Children produced a greater proportion of cognates than non-cognates, and the interval between producing a word and its translation equivalent was about 10-15 days shorter for cognates than for non-cognates. The findings suggest that cognate learning is facilitated in early bilingual vocabulary development, such that phonological overlap supports bilinguals in learning phonologically similar words across their two languages.

Patterns of language switching and bilingual children's word learning: An experiment across two communities.

Language switching is common in bilingual environments, including those of many bilingual children. Some bilingual children hear rapid switching that involves immediate translation of words (an 'immediate-translation' pattern), while others hear their languages most often in long blocks of a single language (a 'one-language-at-a-time' pattern). Our two-site experimental study compared two groups of developing bilinguals from different communities, and investigated whether differences in the timing of language switching impose different demands on bilingual children's learning of novel nouns in their two languages: do children learn differently if they hear a translation immediately vs. if they hear translations more separated in time? Using an at-home online tablet word learning task, data were collected asynchronously from 3- to 5-year-old bilinguals from French-English bilingual families in Montreal, Canada (N = 31) and Spanish-English bilingual families in New Jersey, USA (N = 22). Results showed that bilingual children in both communities readily learned new words, and their performance was similar across the immediate-translation and one-language-at-a-time conditions. Our findings highlight that different types of bilingual interactions can provide equal learning opportunities for bilingual children's vocabulary development.

Are translation equivalents special? Evidence from simulations and empirical data from bilingual infants.

The acquisition of translation equivalents is often considered a special component of bilingual children's vocabulary development, as bilinguals have to learn words that share the same meaning across their two languages. This study examined three contrasting accounts for bilingual children's acquisition of translation equivalents relative to singlets (i.e., words that are first labels for a referent): the Avoidance Account whereby translation equivalents are harder to learn, the Preference Account whereby translation equivalents are easier to learn, and the Neutral Account whereby translation equivalents and singlets are learned similarly. To adjudicate between these accounts, Study 1 explored patterns of translation equivalent learning under a novel computational model - the Bilingual Vocabulary Model - which quantifies translation equivalent knowledge as a function of the probability of learning words in each language, and includes a bias parameter that varies the difficulty of learning translation equivalents according to each account. Study 2 tested model-derived predictions against vocabulary data from 200 French-English bilingual children aged 18-33 months. Results showed a close match between the model predictions and bilingual children's patterns of translation equivalent learning. At smaller vocabulary sizes, data matched the Preference Account, while at larger vocabulary sizes they matched the Neutral Account. Our findings show that patterns of translation equivalent learning emerge predictably from the word learning process, and potentially reveal a qualitative shift in translation equivalent learning as bilingual children develop and learn more words.

The development of gaze following in monolingual and bilingual infants: A multi-laboratory study.

Determining the meanings of words requires language learners to attend to what other people say. However, it behooves a young language learner to simultaneously encode relevant non-verbal cues, for example, by following the direction of their eye gaze. Sensitivity to cues such as eye gaze might be particularly important for bilingual infants, as they encounter less consistency between words and objects than monolingual infants, and do not always have access to the same word-learning heuristics (e.g., mutual exclusivity). In a preregistered study, we tested the hypothesis that bilingual experience would lead to a more pronounced ability to follow another's gaze. We used a gaze-following paradigm developed by Senju and Csibra (Current Biology, 18, 2008, 668) to test a total of 93 6- to 9-month-old and 229 12- to 15-month-old monolingual and bilingual infants, in 11 laboratories located in 8 countries. Monolingual and bilingual infants showed similar gaze-following abilities, and both groups showed age-related improvements in speed, accuracy, frequency, and duration of fixations to congruent objects. Unexpectedly, bilinguals tended to make more frequent fixations to on-screen objects, whether or not they were cued by the actor. These results suggest that gaze sensitivity is a fundamental aspect of development that is robust to variation in language exposure.