This article presents data on lexical development of 881 Israeli Hebrew-speaking monolingual toddlers ages 1;0 to 2;0. A Web-based version of the Hebrew MacArthur-Bates Communicative Development Inventories (H-MB-CDI) was used for data collection. Growth curves for expressive vocabulary, receptive vocabulary, actions and gestures were…

There is considerable controversy over the factors that shape infants' developing knowledge of grammar. Work with artificial languages suggests that infants' ability to track statistical regularities within the speech they hear could, in principle, support grammatical development. However, little work has tested whether infants' performance on…

Children's early vocabulary shows sex differences -- with boys having smaller vocabularies than age-comparable girls -- a pattern that becomes evident in both singletons and twins. Twins also use fewer words than their singleton peers. However, we know relatively less about sex differences in early gesturing in singletons or twins, and also how…

Fourteen-month-old infants are unable to link minimal pair nonsense words with novel objects (Stager & Werker, 1997). Might an adult's productions in a word learning context support minimal pair word-object association in these infants? We recorded a mother interacting with her 24-month-old son, and with her 5-month-old son, producing nonsense…

The goals of this study were to analyze the growth and stability of vocabulary, mean length of the three longest utterances (MLLUw), and sentence complexity in European Portuguese-speaking children aged 1;4-2;6, to explore differences in growth as a function of personal and family-related variables, and to investigate the inter-relationships among…

Pierce "et al." (2017) have proposed that variations in the timing, quality and quantity of language input during the earliest stages of development are related to variations in the development of phonological working memory and, in turn, to later language learning outcomes. To examine this hypothesis, three groups of children who are…

Research on sources of individual difference in parental Infant-Directed Speech (IDS) is limited and there is a particular lack of research on fathers' compared to mothers' speech. This study examined the predictive relations between infant characteristics and variability in paternal lexical diversity (LD) in dyadic free play with two-year-olds (M…

Children are believed to construct their causal theories through talk and interaction, but with the exception of a few studies, little or nothing is known about how young children justify and build theories of the world together with same-age peers through naturally occurring interaction, Children's sensitivity to when a pair or group of…

This study explored preschool age and gender differences in help-seeking within the theoretical framework of scaffolded problem-solving and self-regulation (Bruner, 1986; Rogoff, 1990; Vygotsky, 1978; 1986). Within-subject analyses tracked changes in help-seeking among 62 preschoolers (34 boys, 28 girls, mean age 4.22 years) solving a challenging…

Parents of 592 children between the age of 0 ; 8 and 1 ; 4 completed the Estonian adaptation of the MacArthur-Bates Communicative Development Inventory (ECDI Infant Form). The relationships between comprehension and production of different categories of words and gestures were examined. According to the results of regression modelling the…

A set of tri-zygotic quadruplets, three girls and one boy, participated in weekly observations from 1;2 to 1;10 (years;months), a period of transition from prelinguistic gesture to 50 words. In the study, one girl served as a genetic mate to her identical twin and a biological risk mate to her fraternal sister. The biological risk mates achieved…

This paper focuses on the aspects of the lexicon in 66 prematurely born very-low-birth-weight and 87 full-term Finnish children at 2;0, studied using the Finnish version of the "MacArthur Communicative Developmental Inventory". The groups did not differ in vocabulary size. Furthermore, the female advantage in vocabulary size was not seen…