Developmental psychology focuses on how psychological constructs change with age. In cognitive development research, however, the specifics of this emergence is often underspecified. Researchers often provisionally assume linear growth by including chronological age as a predictor in regression models. In this work, we aim to evaluate this…

Children can acquire novel word meanings by using pragmatic cues. However, previous literature has frequently focused on in-the-moment word-to-meaning mappings, not delayed retention of novel vocabulary. Here, we examine how children use pragmatics as they learn and retain novel words. Thirty-three younger children (mean age: 5.0, range: 4.0-6.0,…

The relationship between executive function and second-language ability remains contentious in bilingual children; thus, the current study focused on this issue. In total, 371 Uyghur-Chinese bilingual children ranging from 3 to 6 years old were assessed by a battery of tasks measuring language ability (expressive vocabulary tests, receptive…

Childhood socioeconomic status (SES) is related to disparities in the development of both language and executive functioning (EF) skills. Emerging evidence suggests that language development may precede and provide necessary scaffolding for EF development in early childhood. The present preregistered study investigates how these skills co-develop…

The number of older siblings a child has is negatively correlated with the child's verbal skills, an effect that is well known in the literature. However, few studies have examined the effect of older siblings' sex, of the age gap between siblings, of having foreign-speaking parents, as well as the mediating role of parental interaction. Using…

Learning to walk allows infants to travel faster and farther and explore more of their environments. In turn, walking may have a cascading effect on infants' communication and subsequent responses from caregivers. We tested for an "inflection point"--a dramatic shift in the developmental progression--in infant communication and caregiver…

There is evidence showing that both maturational and environmental factors can impact on later language development. On the one hand, preterm birth has been found to increase the risk of deficits in the preschool and school years. Preterm children show poorer auditory discrimination, reading difficulties, poor vocabulary, less complex expressive…

Recent evidence suggests that deaf children with CIs exposed to nonnative sign language from hearing parents can attain age-appropriate vocabularies in both sign and spoken language. It remains to be explored whether deaf children with CIs who are exposed to early nonnative sign language, but only up to implantation, also benefit from this input…

Prior linguistic knowledge is proposed to support the acquisition and consolidation of new words. Adults typically have larger vocabularies to support word learning than children, but the developing brain shows enhanced neural processes that are associated with offline memory consolidation. This study investigated contributions of prior knowledge…

Auditory speech discrimination is essential for normal language development. Children born preterm are at greater risk of language developmental delays. Using functional near-infrared spectroscopy at term-equivalent age, the present study investigated early discrimination of speech prosody in 62 neonates born between week 23 and 41 of gestational…

Adults and toddlers systematically associate pseudowords such as "bouba" and "kiki" with round and spiky shapes, respectively, a sound symbolic phenomenon known as the "bouba-kiki effect." To date, whether this sound symbolic effect is a property of the infant brain present at birth or is a learned aspect of language…

This study evaluates whether early vocalizations develop in similar ways in children across diverse cultural contexts. We analyze data from daylong audio recordings of 49 children (1-36 months) from five different language/cultural backgrounds. Citizen scientists annotated these recordings to determine if child vocalizations contained canonical…

The acquisition of language involves the functional specialization of several cortical regions. Connectivity between these brain regions may also change with the development of language. Various studies have demonstrated that the arcuate fasciculus was essential for language function. Vocabulary learning is one of the most important skills in…

Children who rapidly recognize and interpret familiar words typically have accelerated lexical growth, providing indirect evidence that lexical processing efficiency (LPE) is related to word-learning ability. Here we directly tested whether children with better LPE are better able to learn novel words. In Experiment 1, 17- and 30-month-olds were…

Iconicity--the correspondence between form and meaning--may help young children learn to use new words. Early-learned words are higher in iconicity than later learned words. However, it remains unclear what role iconicity may play in actual language use. Here, we ask whether iconicity relates not just to the age at which words are acquired, but…