I hope we can still be friends. The classic line almost anyone has heard before after breaking up. And while you probably could be friends, is it actually a good idea? Well, only if it is practical, according to new research published in Personal Relationships.

In the study, researchers conducted two experiments. In the first, around 170 women and 110 men answered a series of questionnaires to determine why men and women stay friends after breaking it off, and how satisfaction (or dissatisfaction) over the breakup could predict the success of a new friendship. In the second, roughly 300 women and 250 men answered the same series of questions to confirm if certain motives correlated to amicable friendships.

While the study was successful, many of the friendships were not. Ultimately, researchers found four main reasons why people stay friends with an ex (which dictated how long the friendship would last, and how positive it would be):

1. It's Easier. Maybe you stay friends because you share a gym membership, or because you have a few assets together. Financial ties are a strong influence.

 

2. You're Not Over Her You're not over this relationship, and you're hoping by staying friendly, dropping not-so-subtle hints, and keeping close will somehow lure her back in

 

3. Security. You hang around your ex because you value her emotional support and guidance.

 

4. Kindness If you're a decent human being with half a heart, you'll probably want to touch base with your ex every once in a while to see how she is doing.

 

Those who stayed friends because of unresolved feelings had more negative relationships—meaning one or both parties felt depressed, jealous, or brokenhearted, and, ironically enough, longer “friendships,” researchers explain. That is to say: People let these “friendships” go on, even if they're not benefitting. Most people struggle to cut the cord.