Scott Alexander analyzes a study on lactation fetishes and its critical window theory, using his own survey data to suggest an alternative explanation based on birth order effects. Longer summary

Scott Alexander examines a study by Enquist et al on lactation fetishes, which suggests a critical window theory for fetish development based on exposure during childhood. The study found that lactation fetishists had more younger siblings, seemingly supporting this theory. However, Scott compares this to his own survey data, which shows a similar pattern for intellectual curiosity. He then uses data from the SSC 2019 Survey to test both hypotheses, looking at various fetishes and sibling relationships. The results suggest that having older siblings suppresses fetish formation, rather than younger siblings causing it. This casts doubt on the critical window theory and indicates that birth order effects on openness to experience might better explain the original study's findings. Shorter summary

Scott Alexander presents survey data showing a strong overrepresentation of oldest siblings among his blog readers, challenging the view that birth order effects are negligible. Longer summary

Scott Alexander challenges the mainstream view that birth order effects are negligible, presenting data from his blog survey that shows a strong tendency for oldest children to be overrepresented among his readers. He finds that in families of two children, 71.4% of respondents were the older sibling, with similar patterns in larger families. While he couldn't fully replicate previous studies' findings on IQ differences, he did find a significant difference in Openness to Experience. Scott suggests that birth order may have a stronger effect on intellectual curiosity than previously thought, which could explain the skewed ratios in certain communities. He calls for further research to understand the mechanisms behind this effect and its potential implications. Shorter summary