>>4317801i spoke with a girl about this specific thing im going to say , religions such as islam separate gender usually after puberty but at most cases before , where it somewhats dehumanizes the other gender as a tool for sex or as they excuse themself"marriage" , so when got religions like islam that isolate males and females and make their interactions minimal with also cousin marriage and marrying some relatives is allowed , this will cause inbreeding cases (incest) to go higher