PROJECT SUMMARY
Bilingually exposed Latino students are often characterized as being at-risk for reading difficulties, despite their
being two possible language pathways toward successful reading for bilinguals. Heightened economic hardship
accounts for such academic difficulties as do the sociolinguistic realities of bilingualism in the US (subtractive
bilingual schooling), which threaten Latino children's bilingual status. Reading difficulties for a large segment of
the U.S. population represents a critical national health concern given the connection to unhealthy life outcomes.
Thus, the long-term goal of this renewal R15 application is to identify the features of Spanish-speaking Latino
children's early language environments that are associated with bilingual trajectories. The study findings would
provide a scientific basis for interventions and policies aimed at promoting the bilingual development and
academic well-being of Latino children. Our original R15 findings indicate that “language nutrition” or exposure
to primary caregivers' diverse language promotes bilingual children's “language health,” that is, bilingual
development. Despite widespread agreement on the critical importance of primary caregivers' directed input,
there is a limited understanding of the multiple input sources (beyond primary caregivers) and input types
(beyond direct input, including overheard input) that promote bilingual development. This is partly due to the
field's narrowed focus on bilingual children's amount of language exposure and that existing models of language
development are overwhelmingly based on culturally specific monolingual learners. Thus, in this renewal
application, we broaden the research lens to meet two new aims: 1) establish whether and how multiple language
input sources (primary, secondary, other) and types (diversity, amount; direct, overheard) contribute uniquely
to bilingual children's language outcomes and 2) determine the bi-directional dependency of language use
between children and their multiple interlocutors. We will collect video and audio recorded speech samples,
including day-long recordings, from bilingually exposed children and their multiple interlocutors, including
primary (mother), secondary (father), and other caregivers (grandparents). We will recruit a total of 80 target
children from Latino homes that represent a range of Spanish and English exposure levels. Our purposeful
longitudinal sampling of multiple inputs and child output (at child age 12, 18, 24, 30 and 36 months) will allow
for a fine-grained analysis of how caregiver input functions as part of a dynamic system of transactional
interactions with learners (verbally, non-verbally). Taking a multi-method approach, we supplement naturalistic
observations with caregiver interviews (semi-structured and questionnaires) and experimental manipulations of
input, using word learning and language modeling paradigms. Highly trained student researchers will collect,
transcribe, and code recordings, administer researcher-developed and standardized assessments of children's
language (vocabulary, syntax) and nonverbal behaviors (gesture), as well as carry out on-campus experiments.