Why do women tend to be more religious than men?

I was having a discussion with a friend of mine, who is on a student visa from a country in the Middle East that is mostly Muslim.  His family is Muslim, but he's discovered that he's atheist.  Not only is it difficult socially, but he faces the death penalty in his country if he's proven to be atheist.

While we were on the subject, we started talking about how difficult it will be for him to find a mate when he finishes school and returns home.  He's afraid that his lack of religious conviction will keep him from finding women to date or to marry.  He doesn't want to marry a woman who's married to her faith.

I told him that it's difficult for atheists to meet people of the opposite sex, here, too.  But then I started thinking about how it must be harder for atheist men to meet atheist women, because men outnumber women in this category.  I wonder why.

In an effort to understand this phenomena, I did a little research via the Internet, and I found this article that throws out some possibilities.  I wonder if it's really because more women really believe in religious dogma, or if it's social pressure that make them feel that they have to put on a religious front.

Of course, in some parts of the world, the pressure to be religious is more than just social, but in parts of the world where it's not, why do you think there are more men who are freethinkers than women?