I also went to school outside America, ten years ago. I don't have a decided opinion on mixed schools either way - there are definitely benefits to single sex e

I also went to school outside America, ten years ago. I don't have a decided opinion on mixed schools either way - there are definitely benefits to single sex education, but they need to be weighed against the artificiality of the environment, as you say. Its worth noting that many of the straight up academic benefits of gender separation appear to be stronger for girls - higher participation in STEM subjects, more participation in class, better performance in general - but there is some evidence that boys perform better academically with girls in the class. (this might be a little out of date, I am less interested in the theory of school since I left it myself). I got the impression that the idea was basically to reduce social distraction during school: one could always hang out with the opposite sex after school (and most people did).