Single-gender schools are a weird phenomenon here in our area. There is just one school which separates both sexes in Cantabria, and in my opinion it seems really old-fashioned. I cannot understand how this kind of school keeps on existing, since I think society's mentality has evolved and become more involved with gender equality.
A long time ago (unfortunately, not so long), separating boys and girls at school was common. Even when the situation changed and boys shared their classtime with girls, the most distinguished and richest families sent their children to single-gender boarding schools. Why? Does it mean girls should learn different things from boys, or the other way round? Must women be separated from men because of any incomprehensible reason? Personally, I think it is a mistake to separate both genders as children should be prepared at school to face their future life, and they won't find only their own gender outside there. They also have to learn to socialize with the opposite sex, and school is the right place to do it.
All in all, I can't find any benefit in these schools, just disadvantages. Segregating the children looks sexist to me, as if girls couldn't carry out the same tasks as boys.
I believe those parents who send their children to those schools should think about the consequences that this may have on their children's future life.