Scott Alexander examines the paradoxical relationship between autism and intelligence, discussing genetic and environmental factors, and proposing explanatory models for the observed lower IQ in autistic individuals despite genetic links to higher intelligence. Longer summary

Scott Alexander explores the paradoxical relationship between autism and intelligence. While genetic studies show a link between autism risk genes and high IQ, autistic individuals generally have lower intelligence than neurotypical controls. The post discusses three main causes of autism: common 'familial' genes that increase IQ, rare 'de novo' mutations that are often detrimental, and non-genetic factors like obstetric complications. Scott examines various studies and proposes that even after adjusting for mutations and environmental factors, autism still seems to decrease IQ. He introduces a 'tower-vs-foundation' model to explain this phenomenon, where intelligence needs a strong foundation to support it, and an imbalance can lead to autism. The post concludes with a list of findings and their associated confidence levels. Shorter summary

Scott Alexander challenges the popular interpretation of the Rat Park study, arguing that addiction is not solely caused by poor environments and emphasizing genetic factors in addiction susceptibility. Longer summary

Scott Alexander critiques the 'Rat Park' study and its popularized interpretation that drug addiction is primarily caused by poor social environments. He presents historical examples of addiction in seemingly happy or fortunate individuals, such as Ogedei Khan and Native Americans, to challenge this view. The post then discusses the genetic factors in addiction, citing twin studies and known genetic markers. Scott acknowledges that unhappiness likely contributes to drug use but argues that the relationship between environment and addiction is more complex than the Rat Park model suggests. He proposes a toy model where other sources of reward can help resist drug addiction, but maintains that biological interventions like deregulating suboxone and researching psychedelic therapy are more immediately effective for helping addicts. Shorter summary