We studied the effect of the number and characteristics of siblings (sex, age) on school achievement in several grades (kindergarten, first grade, and fifth grade), in two large French cohorts, with more than 16,000 children. Running linear mixed-effects models, we find that, independently of socioeconomic status, having more siblings is…

Growing up with multiple siblings might negatively affect language development. This study examined the associations between birth order, sibling characteristics and parent-reported vocabulary size in 6163 Norwegian 8- to 36-month-old children (51.4% female). Results confirmed that birth order was negatively associated with vocabulary, yet…

This study examined whether autistic people with siblings score higher on measures of empathy than those without siblings. Cohorts of autistic children (n = 939; mean age = 7.35 years (SD = 2.15)) and autistic adults (n = 736; mean age = 37 years (SD = 12.39)) from the Cambridge Autism Research Database (CARD) were each divided into two groups:…

This study investigated parents' and siblings' knowledge use during naturalistic teaching episodes in the home. Thirty-seven middle-class families were observed for six 90-minute sessions (siblings aged 4 and 6 years). Parent and sibling teaching sequences were coded for knowledge type (conceptual, procedural), conceptual subcategories (social…

Background &aims: Language abilities of autistic children and children at elevated likelihood for autism (EL-siblings) are highly heterogeneous, and many of them develop language deficits. It is as of yet unclear why language abilities of autistic children and EL-siblings vary, although an interaction of multiple influential factors is likely…