ASD heritability stable over decades

A nationwide Swedish twin study (JAMA Psychiatry, 2020) found autism spectrum disorder heritability around 0.88–0.97, with no evidence that environmental influence increased across birth cohorts from 1982 to 2008. Rising autism diagnoses thus likely reflect diagnostic and measurement shifts rather than a changing causal mix. — This anchors autism debates in strong genetic evidence and redirects policy toward measurement, diagnosis, and services rather than speculative environmental culprits.