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 explains how to interpret 23andMe genetic data using SNPedia, listing various SNPs and their alleged effects while emphasizing the unreliability of such interpretations. Longer summary

Scott Alexander humorously explores how to use 23andMe genetic testing data 'irresponsibly' by looking up various SNPs (Single Nucleotide Polymorphisms) and their purported effects. He provides instructions on how to access raw genetic data from 23andMe and interpret it using SNPedia. The post then lists several interesting SNPs associated with traits like violence, empathy, anxiety, divorce risk, and longevity. Scott repeatedly emphasizes that these associations are often unreliable, exaggerated, or misinterpreted, and should be taken as entertainment rather than medical advice. Shorter summary