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