The broad autism phenotype: birth order as it relates to pragmatic language and self-competence in siblings (2015)

Undergraduate: Sarah Griffin

Faculty Advisor: Steven Reznick
Department: Psychology & Neuroscience

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According to the CDC, in 2014, 1 in 64 children in the United States are diagnosed with autism. Based off of data from the concurrent US census, 297,428 US households are living with at least 1 child with autism and 1 typically-developing child. There are many existing studies on parental outcomes associated with having a child with autism, but less so concerning sibling outcomes. This study focuses on birth order and its relation to social language use. In turn, this study follows the theory that social language use will predict a typically-developing sibling's self-competence. Based off of previous studies, younger siblings will have lower social language use and, subsequently, self-competence scores. Parents of both a child with autism and a typically-developing child in the North Carolina Autism Registry were emailed and asked to complete two surveys themselves and have their 10-14 year old typically-developing child complete one survey online. Based off of initial data, there does not appear to be any significant birth order differences, but a larger sample size may illuminate trends.