Scott Alexander partially retracts and corrects his previous findings on age gaps and birth order effects after errors were identified in his analysis. Longer summary

Scott Alexander partially retracts his previous findings on age gaps and birth order effects. He acknowledges that Bucky, a Less Wrong user, found errors in his analysis of SSC survey data. While the original conclusion about firstborn children being overrepresented in high-openness STEM types remains valid, the specific findings about age gaps were partially incorrect. Scott explains the errors, presents Bucky's corrected analysis, and discusses the implications. He emphasizes the importance of data transparency and encourages readers to double-check his work. Shorter summary

Scott Alexander analyzes birth order effects in SSC readers, finding strong effects for sibling age gaps of 1-7 years, with a significant drop-off after 7 years. Longer summary

Scott Alexander investigates birth order effects using data from the 2019 Slate Star Codex survey. He finds that firstborns are overrepresented among SSC readers, replicating previous findings. The study focuses on how age gaps between siblings affect this birth order effect. Results show strong effects for age gaps of 1-7 years, with a dramatic decrease for gaps larger than 7 years. Scott discusses possible explanations for these findings, including intra-family competition and parental investment hypotheses. He notes that the results don't seem consistent with some other proposed mechanisms like maternal antibodies or vitamin deficiencies. The post ends with a call for further replication and expansion of these results. Shorter summary

Scott Alexander outlines 18 preregistered investigations for the 2019 SSC survey, covering topics from psychiatric medication effects to birth order influences. Longer summary

Scott Alexander preregisters 18 investigations for the 2019 Slate Star Codex survey. These investigations cover a wide range of topics including psychiatric medication effects, social class perceptions, life history strategies, gender bias, imposter syndrome, and birth order effects. The post begins by urging readers to take the survey before reading further to avoid bias. Each investigation is briefly described, often including the reasoning behind it or the specific analysis method to be used. The investigations touch on fields such as psychology, sociology, psychiatry, and genetics, reflecting the diverse interests of the blog's audience. Shorter summary

The author revisits their belief in genetic determinism, presenting evidence that environmental factors, especially in divorce, have significant non-genetic effects on children's outcomes. Longer summary

The post discusses the author's initial belief in the genetic determinism thesis from 'The Nurture Assumption', which argues that parenting has little effect on children's outcomes compared to genetics. The author then presents evidence from divorce studies that challenge this view, showing that environmental factors, particularly family conflict, do have significant effects on children. The post reviews several studies that disentangle genetic and environmental effects of divorce, concluding that there are indeed non-genetic negative impacts of divorce on children. The author acknowledges being wrong about shared environment effects being negligible and suggests that short-term environmental impacts can have long-lasting consequences. Shorter summary