Sibling relationships are argued to offer a rich social context for the development of young children's theory of mind (ToM). There is evidence that the presence of siblings, particularly older siblings, may promote preschoolers' ToM, but it has not been investigated among toddlers. This study evaluated differences in early manifestations of ToM…

In 2 cross-lagged, longitudinal studies we contrasted parental talk about want in a single context versus multiple contexts. Study 1 examined thirty-two 2 year olds, with mothers describing pictures to children. Mothers could use want in zero, one, or multiple contexts. Children whose mothers used want in multiple contexts experienced a…

The results from a large-scale study on toddlers' language acquisition in European Portuguese are presented. Toddlers' lexical and grammatical competencies were assessed using the MacArthur-Bates Communicative Development Inventory: Words and Sentences. The results, based on 3012 reports completed by parents, indicate an increase in the lexical…

The purpose of this study was to understand vocabulary characteristics in toddlers who are late talkers (LT) as compared with age-matched (AM) and vocabulary-matched (VM) peers. The semantic categories (e.g., animals, foods, toys) and the percentage of nouns, verbs, and closed-class words in the vocabularies of 36 toddlers (12 LT, 12 AM, 12 VM)…

A community sample of 192 parents reported on their children's restricted and repetitive behaviors (RRBs) at mean ages 15 months (N = 138), 26 months (N = 191), and 77 months (N = 125) using the Repetitive Behavior Questionnaire-2 (RBQ-2). Consistent with previous factor analytic research, 2 factors were found at each age: 1 comprising repetitive…

This cross-linguistic study investigated whether the native language has any influence on lexical composition among Italian (N = 125) and Finnish (N = 116) very preterm (born at <32 gestational weeks) children at 24 months (controls: 125 Italian and 146 Finnish full-term children). The investigation also covered the effect of maternal education…

Recent studies demonstrate that emerging literacy depends on earlier language achievement. Importantly, most extant work focuses on "parent-reported production" prior to 30 months of age. Of interest is whether and how "directly assessed vocabulary comprehension" in the 2nd year of life supports vocabulary and kindergarten…

Recent work has shown that children have detailed phonological representations of consonants at both word-initial and word-final edges. Nonetheless, it remains unclear whether onsets and codas are equally represented by young learners since word edges are isomorphic with syllable edges in this work. The current study sought to explore toddler's…

The field of early autism research is in dire need of outcome measures that adequately reflect subtle changes in core autistic behaviors. This article compares the ability of a newly developed measure, the Brief Observation of Social Communication Change (BOSCC), and the Autism Diagnostic Observation Schedule (ADOS) to detect changes in core…

This article describes the European Portuguese MacArthur-Bates Communicative Development Inventories short forms, the first published instruments for the assessment of language development in EP-learning infants and toddlers. Normative data from the EP population are presented, focusing on developmental trends for vocabulary learning, production…

Purpose: The current study used an intervention design to test the hypothesis that parent input sentences with diverse lexical noun phrase (NP) subjects would accelerate growth in children's sentence diversity. Method: Child growth in third person sentence diversity was modeled from 21-30 months (n = 38) in conversational language samples obtained…

Contrast information could be useful for verb learning, but few studies have examined children's ability to use this type of information. Contrast may be useful when children are told explicitly that different verbs apply, or when they hear two different verbs in a single context. Three studies examine children's attention to different types of…

This paper compared the vocabulary size of a group of 250 bilinguals aged 24-36 months acquiring six different language pairs using an analogous tool, and attempted to identify factors that influence vocabulary sizes and ultimately place children at risk for language delay. Each research group used adaptations of the MacArthur-Bates Communicative…

The vocabulary size of 16- to 30-month-old children (N = 1235) was assessed using the Estonian adaptation of the MacArthur-Bates Communicative Development Inventory: Words and Sentences (ECDI-II). The relationship between children's expressive vocabulary size and different factors of the child and his/her social environment was examined. Results…

The present study explores the vocabulary development of bilingual children when neither of their languages has a minority language status. With both languages having high relative prestige, it is possible to address the impact of exposure variables: age of onset, length of exposure, and frequency of exposure (FoE) to both languages. Parents of 40…