Sounds about right

Why single-sex schools are bad for your health (if you're a boy)

This study from England will apparently show:

....that boys taught in singlesex schools are more likely to be divorced or separated from their partner than those who attended a mixed school by their early 40s.

I am not surprised. I went to a small Catholic primary school and then a State (mixed sex) high school. Many of my former primary school (male) friends went to a Catholic single sex high school. It always seemed to me that their experience gave them a peculiar, competitive and overall unpleasant attitude towards girls. It's hard to describe it exactly, but it still seemed quite distinct to me. Regular religious instruction in high school seemed to have an extremely limited influence on sexual behaviour, too.

I am not sure that it is a good idea for girls either. I was told by a woman I was dating once about how much she hated the social experience of her Catholic high school due to the incredible level of, well, bitchiness between the girls. One might have thought that, in the absence of males to directly compete about, there would be less of that, but apparently not.

It's a small sample, I know, but it's enough for me to want to make sure my kids both go to mixed sex high schools.