The current study investigated the impact of birth order on vocabulary and social language development in 1338 first-born and 1049 s-born autistic youth (M age = 9.03 years, SD = 3.57; 86.4% male) from the Simons Simplex Collection. Frequentist and Bayesian analyses revealed mixed findings in language development. There were no differences in…

Although water-based approaches have been shown to be beneficial for children with Autism Spectrum Disorder (ASD), no study thus far has directly investigated the effects of such intervention programs on language skills. The present study aims to evaluate the efficacy of the Aquatic Speech and Language Therapy (ASLT) program, which is a new,…

Purpose: The purpose of this study was to evaluate if higher quantity, diversity, and grammatical informativeness of verb phrases in parent follow-in utterances (i.e., utterances that mapped onto child attentional leads) were significantly related to later expressive verb vocabulary in children with autism spectrum disorder (ASD). Method: We…

The relation between caregiver follow-in utterances with verbs presented in different states of dyadic engagement and later child expressive verb vocabulary in children with autism spectrum disorder (ASD) was examined in 29 toddlers with ASD and their caregivers. Caregiver verb input in follow-in utterances presented during higher order supported…

Thirty-one children with and without autism spectrum disorder were asked to draw the meaning of 10 basic concepts. Following each drawing, children explained their drawing to the experimenter. Transcripts of the drawing task were coded for children's use of personal pronouns and internal state terms. Children's use of on- and off-task comments…

One of the earliest indicators of autism spectrum disorder (ASD) is delay in language and social communication. Despite consensus on the benefits of earlier diagnosis and intervention, our understanding of the language growth of children with ASD during the first years of life remains limited. Therefore, this study compared communication growth…

Purpose: Several studies have reported that "useful speech" at 5 years of age predicts outcomes in individuals with autism spectrum disorder (ASD), but this skill has been vaguely defined. This study investigates which specific aspects of expressive language in children with ASD best predict adult language and communication outcomes.…

We examined differences between children with autism spectrum disorder and typically developing children over an 8-month period in: (a) longitudinal associations between expressive and receptive vocabulary and (b) the extent to which caregiver utterances provided within an "optimal" engagement state mediated the pathway from early…

Purpose: Children with autism spectrum disorder (ASD) are at increased risk of experiencing difficulties with the development of literacy, including the emergent literacy skills recognized to underpin conventional literacy success. Comprehensive assessment is essential. Characteristics of ASD can make assessment challenging, and this can be…

Purpose: Language is related to false-belief (FB) understanding in both typically developing children and children with autism spectrum disorder (ASD). The current study examined the role of complementation and general language in FB understanding. Of interest was whether language plays similar or different roles in the groups' FB performance.…

Purpose: Correlates of receptive-expressive vocabulary size discrepancies may provide insights into why language development in children with autism spectrum disorder (ASD) deviates from typical language development and ultimately improve intervention outcomes. Method: We indexed receptive-expressive vocabulary size discrepancies of 65 initially…

Purpose: Some boys with autism spectrum disorder (ASD) and boys with fragile X syndrome and a codiagnosis of ASD (FXS+ASD) have impairments in expressive grammatical abilities. The current study compared grammatical performance in these 2 groups of school-age boys. Method: Thirty-seven boys similar on mean length of utterance participated in the…

Background: Individuals with autism spectrum disorder (ASD) have been characterized as having deficits in social communication and empathy which present difficulties in the areas of social reciprocity, sharing of emotions and developing and maintaining relationships. This study explores the associations between vocabulary, executive function…

Recognizing early risk markers in young children with autism spectrum disorder (ASD) is critical for timely diagnosis and intervention. The purpose of this study was to extend previous findings regarding language milestones to a longitudinal design, in which ages of expressive language milestones (i.e., first words, first phrases) could serve as…

Purpose: Vocabulary is a domain of particular challenge for many children with autism spectrum disorder (ASD). Recent research has drawn attention to ways in which lexical characteristics relate to vocabulary acquisition. The current study tested the hypothesis that lexical characteristics account for variability in vocabulary size of young…