https://arnoldkling.substack.com/p/on-rfk-jr-on-autism?triedRedirect=true

Is Autism Genetic?

In a recent discussion prompted by a speech from RFK, Jr. about autism, various experts, including Jill Escher (JE), Cremieux Recueil (CR), and Emily Oster (EO), shared insights into the genetic basis of autism and the rise in diagnosed cases over time.

Summary of Points

• Genetic Basis of Autism:

  • All three experts agree that autism is primarily genetic. EO cites a meta-analysis indicating a heritability factor between 65% and 90%, which suggests that genetic causes explain the majority of variation in autism cases.
  • Autism is influenced by many genes rather than a single one. JE emphasizes research on how toxic exposures might impact parental germ cells, raising questions about distinguishing genetic from environmental factors.

• Environmental and Other Factors:

  • There is no concrete evidence supporting environmental causes for autism; however, certain factors might contribute slightly to rising rates.
  • Older parental age and improved healthcare might influence autism rates. CR and EO discuss how older paternal age could lead to age-related mutations in sperm, and better healthcare has increased survival rates of potentially autistic individuals.

• Rise in Autism Diagnoses:

  • There is disagreement on whether the rise in autism cases reflects a real increase or is due to changes in diagnostic practices and awareness.
  • JE presents historical data showing a stark increase in autism cases in California, which might be attributed to enhanced diagnostic criteria and reporting systems.
  • CR and EO argue that much of the increase can be explained by improved diagnosis and awareness rather than a real surge in cases. EO points out that more diagnoses lead to better treatment options, while CR questions the motivations behind the rising diagnoses.

• Diagnostic Challenges:

  • There is no definitive test for autism, leading to varying interpretations of behavioral patterns by clinicians.
  • The discussion highlights the complexity of defining autism and the potential biases in historical data collection.

Implications

This conversation emphasizes the primarily genetic nature of autism but does not dismiss potential minor contributions from environmental or other non-genetic factors. There is a critical need for continued research into autism’s origins, the impacts of parental age, and healthcare improvements on autism incidence. Furthermore, the accurate diagnosis of autism remains a challenge, with significant implications for treatment and policy development.