Bad news, ladies. We have a new deal-breaker to add to your “do not date” list. In addition to the slackers, the druggies, the liars and the thieves – steer clear of men who attended all-boys schools.

Read 7 Guys You Should Never Date

According to new research published this week, boys who studied at single-sex school are more likely to get divorced or separated by the time they hit 40 than men from mixed-gender schools.

Guess this means we can’t just ask a guy where he went to college on a first date. Now we need to inquire as to the gender balance of his kindergarten class.

The study covered 17,000 adults (all born in 1958), who attended various types of educational institutions. The results were presented this week in Cambridge, England, by London University’s Institute of Education Professor Diana Leonard.

The findings confirm a long-held suspicion among educators that boys who don’t spend time with girls in an educational environment struggle to relate to them later in life.

Um, we could have told them that. It’s fairly obvious that most men need a whole lot of practice around women. Depriving boys of that exposure early on could definitely hinder their love lives down the road.