No effects of siblings and twin testosterone transfer on autistic traits.
Melanie M de WitSander BegeerMichel G NivardElsje van BergenPublished in: JCPP advances (2022)
We did not find increased autistic traits in girls with a twin brother compared to girls with a twin sister. This finding contributes to a body of literature that rejects the twin testosterone transfer hypothesis. In addition, we found little evidence for pre- and postnatal sibling influences. Our findings align with high heritability and absence of shared-environmental influences in ASD.