Daylong at-home audio recordings from 10 Tseltal Mayan children (0;2-3;0; Southern Mexico) were analyzed for how often children engaged in verbal interaction with others and whether their speech environment changed with age, time of day, household size, and number of speakers present. Children were infrequently directly spoken to, with most…

Child language acquisition research has provided ample evidence of lexical frequency effects. This corpus-based analysis introduces a novel frequency measure shown to significantly constrain adult language variation, but heretofore unexplored in child language acquisition research. Among adults, frequent occurrence of a form in a particular…

The prevalence of autism/autism spectrum disorder (ASD) has been increasing across the world. Previous studies in Norway reported, that the prevalence rate for 0-10-year-old children is 1 in 166, and in the case of 11-year-old children it is 1 in 125. Moreover, another nationwide study discovered that 1 in 192 males and 1 in 695 females between…

While it is known that the process of becoming literate begins in early childhood and usually involves several years of schooling, research related to cognitive characteristics has been done mostly on illiterate adults, and information concerning illiterate children is therefore limited. The aim of the present study, involving 21 illiterate and 22…

This study sought to determine the prevalence of bruxism in a Mexican community of children with Down syndrome, and to evaluate bruxism's relationship with age, sex, intellectual disability level, and type of chromosomal abnormality of trisomy 21. Using a cross-sectional design, 57 boys and girls (3 to 14 years old) were examined. Three approaches…

Reports on the findings of a comparative study of mental abilities of Mexican and American children. Discusses age, sex, social class, and urban-rural differences, as well as cultural differences. (SS)