Scott discusses how new schizophrenia genetics research confirms that psychiatric conditions combine both 'tradeoff' components (with compensating advantages) and 'failure' components (purely negative), then argues this pattern is common sense for any multifactorial problem. Longer summary

Scott discusses new research on schizophrenia genetics which found two distinct components: one shared with bipolar that increases educational attainment (a tradeoff), and one that decreases IQ (a pure failure). He connects this to his 2021 post on tradeoff vs. failure models of psychiatric conditions, arguing that this pattern is actually common sense - most multifactorial problems naturally combine both types. He illustrates this with everyday examples like poverty (which can result from failures like poor health or tradeoffs like choosing to be a starving artist), relationships, and even physical illnesses like cancer. Scott concludes he has 'dissolved' what he previously saw as a mysterious fact about psychiatric conditions into something obvious: complex multidimensional problems will naturally have multiple causes falling into both the 'by choice' and 'not by choice' categories. Shorter summary

Scott Alexander discusses a study challenging the idea that childhood abuse lowers IQ, and explores its implications for understanding the effects of child abuse on various outcomes. Longer summary

This post discusses a study by Danese et al. challenging the assumption that childhood abuse lowers IQ. The study found that after adjusting for pre-existing factors, there was no significant difference in IQ between abused and non-abused children. Scott Alexander explores the implications of this study in the context of shared-environment-skeptical psychiatry and discusses other studies showing limited effects of child abuse on various outcomes. He notes that while these findings are interesting, they may understate the dangers of severe abuse due to sample size limitations. The post concludes by suggesting that child abuse likely causes PTSD-like symptoms but may not have effects drastically different from normal PTSD. Shorter summary

Scott Alexander examines a study showing positive effects of early intervention on at-risk children, but questions its policy implications due to high costs. Longer summary

Scott Alexander discusses a study on early intervention programs for at-risk children, which showed positive effects on various outcomes at age 25. The study, a randomized controlled trial, found that intensive interventions costing $60,000 per child reduced the odds of developing psychiatric disorders, substance abuse problems, and engaging in criminal behavior. While the results are scientifically interesting, Scott points out some limitations and questions the cost-effectiveness from a policy perspective. He notes that the intervention didn't affect all outcomes equally and that the high cost might not justify the benefits when compared to existing educational spending. Shorter summary

Scott Alexander examines studies linking parental age to psychiatric disorders in children, revealing that the father's age at first child, not at conception, is the key factor. Longer summary

Scott Alexander discusses a study in JAMA Psychiatry about the prevalence of psychiatric disorders in relation to parental age. Initially, it seemed that children of young mothers and old fathers were at higher risk. The study proposed that older fathers accumulate more mutations, leading to higher risk of disorders in their children. However, a clever follow-up study found that the risk is more related to how old the father was when he had his first child, rather than the father's age at conception. This suggests that men with mental health issues or risk factors may take longer to find partners and have children, rather than the age itself being the cause. Scott concludes that this finding is sad on a societal level but personally liberating, as he feels less guilty about potentially having children later in life. Shorter summary