I was recently reading a thread about the pros & cons of single sex schools. Personally, I went to one and I felt it was a good model, since joint activities with the boys' school and other extracurricular activities meant I could still befriend boys outside.
On the thread, quite a few posters were saying that going to a mixed school helped them make friends with boys, rather than seeing them as alien creatures and that it's negative if people are mostly friends with their own sex.
I agree in theory that people should try to have friends of the opposite sex. But otoh how typical is this for adult life? Studies show fairly high numbers for people in their twenties, but these lessen for married people, and are less likely to be 'close' friendships. And ofc there's various reasons for this : worry about male friends having other intentions, jealousy issues if married etc
Interested to hear thoughts..