Children acquire language embedded within the rich social context of interaction. This paper reports on a longitudinal study investigating the developmental relationship between conversational turn-taking and vocabulary growth in English-acquiring children (N = 122) followed between 9 and 24 months. Daylong audio recordings obtained every 3 months…

Researchers agree that early literacy activities, like book sharing and parent-child play, are important for stimulating language development. We hypothesize that book sharing is most powerful because it elicits more interactive talk in young children than other activities. Parents of 43 infants (9-18 months) made two daylong audio recordings…

In languages with evidential marking, utterances consist of an informational content and a specification of the mode of access to that information. In this first longitudinal study investigating the acquisition of the Turkish evidential marker "-mIs" in naturalistic child-caregiver interactions, we examined six children between 8 and 36…

This observational study examined the Iranian mothers' interaction with their typically developing children aged 13-18 months during free play at home (n = 40). The first aim was to determine the main type of Iranian maternal verbal responsiveness. Another aim was to investigate the impact of concurrent prediction of maternal verbal responsiveness…

This paper provides an overview of the features of caregiver input that facilitate language learning across early childhood. We discuss three dimensions of input quality: interactive, linguistic, and conceptual. All three types of input features have been shown to predict children's language learning, though perhaps through somewhat different…

Gestures and vocal elements interact from the early stages of language development, but the role of this interaction in the language learning process is not yet completely understood. The aim of this study is to explore gestural accompaniment's influence on the acoustic properties of vocalizations in the transition to first words. Eleven Spanish…

This study analyzes how others engage rural and urban Mozambican infants during naturalistic observations, and how the proportion of time spent in different engagements relates to infants' language development over the second year of life. Using an extended version of Bakeman and Adamson's (1984) categorization of infant engagement, we…

Findings are presented from the first randomized control trial of the effects of encouraging symbolic gesture (or "baby sign") on infant language, following 40 infants from age 8 months to 20 months. Half of the mothers were trained to model a target set of gestures to their infants. Frequent measures were taken of infant language…

Communicative Development Inventories (CDIs, parent-completed language development checklists) are a helpful tool to assess language in children who are unused to interaction with unfamiliar adults. Generally, CDIs are completed in written form, but in developing country settings parents may have insufficient literacy to complete them alone. We…

This study investigates mothers' responses to infant communication among infants at heightened genetic risk (high risk) of autism spectrum disorder compared to infants with no such risk (low risk). A total of 26 infants, 12 of whom had an older sibling with autism spectrum disorder, were observed during naturalistic in-home interaction and…

This study investigates vocal imitation of prosodic contour in ongoing spontaneous interaction with 10- to 13-week-old infants. Audio recordings from naturalistic interactions between 20 mothers and infants were analyzed using a vocalization coding system that extracted the pitch and duration of individual vocalizations. Using these data, the…

This study analyzed German and Nso mothers' auditory, proximal, and visual contingent responses to their infants' nondistress vocalizations in postnatal Weeks 4, 6, 8, 10, and 12. Visual contingency scores increased whereas proximal contingency scores decreased over time for the independent (German urban middle-class, N = 20) but not the…

Electronic media--whether child-oriented videos and games or background television--is increasingly embedded in young children's lives, raising questions of its impact on children's language skills. New research presents a multitextured picture of how different types of e-media--depending on content, context, and a child's age--can help and hurt.…

The availability of educational programming aimed at infants and toddlers is increasing, yet the effect of video on language acquisition remains unclear. Three studies of 96 children aged 30-42 months investigated their ability to learn verbs from video. Study 1 asked whether children could learn verbs from video when supported by live social…

Infants often protest the activities of their caregivers, and this particular social interaction may provide an important window on early communication and its development. This study used naturalistic methods to investigate the development of vocal protests. Fifteen mother-infant dyads at each of 5 ages, from 3 to 18 months, were observed at…