Are you having trouble keeping a guy or girl? It could be because you're ignoring the nice ones, and they're the key to a happy relationship.

While some women may always be attracted to bad guys, a new study suggests most gals would certainly be better off if they focus their attention on a guy who's simply just nice. The same is true for men when it comes to choosing a mate.

A study out of Michigan State University finds that a nice person makes for a more compatible partner. That’s even true when couples don’t seem to be completely compatible.

The study looked at the effects of different personality traits on happiness for more than 2,500 heterosexual couples with about 20 years of marriage under their belt. The study found that even if couples have similar personality traits, those where a partner is conscientious and nice were more satisfied in their relationship, than those where a partner who was neurotic and even extroverted. And while folks may often look for a partner who has similar personality traits as they do, the study notes that personality actually had little effect on a person’s satisfaction in a relationship.

“People invest a lot in finding someone who’s compatible, but our research says that may not be the end all be all,” lead study author Bill Chopik shares. “Instead, people may want to ask, ‘Are they a nice person?’ ‘Do they have a lot of anxiety?’ Those things matter way more than the fact that two people are introverts and end up together.”