Scott Alexander investigates the unexpectedly high prevalence of joint hypermobility in transgender individuals, exploring various theories and presenting survey data on the phenomenon. Longer summary

Scott Alexander explores the puzzling connection between transgender identity and hypermobile joints, particularly Ehlers-Danlos syndrome (EDS). He presents four theories to explain this correlation: 1) It's a spurious result due to 'Instagrammable' conditions clustering together, 2) Estrogen effects on joints in trans women, 3) Genetic link between gender divergence and joint issues, and 4) Autism as a shared causative factor. Scott favors a theory linking proprioception issues to different reasoning styles, potentially leading to both autism and transgender identity. He presents data from his own survey showing higher rates of joint issues in trans respondents, though with some limitations. The post concludes with plans for further investigation in future surveys. Shorter summary