I think college students—and adults--are often too confident that they have reached the point where they don’t need this kind of separation. Most traditional cultures keep something of this kind of separation until marriage. And I think the traditional cultures are right.
Andrew Byrne of Mercator.net uses Harry Potter to explain it this way:
One way of doing this, which is worth pointing out, is the practicalSometimes parents and authories who are reacting against the permissiveness of our culture go too far in the other direction. I can tell stories about homeschool parents and others who go ballistic just because a boy is talking with a girl unchaperoned. One incident I know of the boy and girl in question turned out to be brother and sister, to the embarrassment of the grownup involved.
separation in Hogwarts school, between boys and girls, giving space for respect
to operate. Separate dormitories (though, interestingly, we are never told what
goes on in the girls’ dormitories, since the story is told principally from the
point of view of Harry). By keeping boys and girls separate in that way, not
forcing them, all the time, to be together, Rowling creates space for each of
them to be themselves, without having to put on an act (such as we see in the
Triwizard Ball, where both boys and girls change, in the presence of the
opposite sex: girls become stunningly beautiful, boys awkward and timid).
Still, I think the point is valid, even for adults. A distinctive men's and women's culture and space is good for the interaction of the sexes.
HT Nancy Brown.