4 ways you must mesh with your man. (RELATIONSHIP ROAD MAP).

You don't need a crystal ball to know if you and your dude will go the distance. Cosmo uncovered what will make or break your bond.

The impulse to spin romantic fantasies about the future you and your new man have in store is practically programmed into the female genetic code. But no matter how perfectly the images play out in your head now, it's no guarantee you really have what it takes to make it last. To figure out your long-term compatibility, you have to examine four key factors. Some good news- If you really dig your dude, you can tip the odds in your favor Luckily, just tackling these topics will give you an edge. "The more couples think about what they want from their relationship and create a vision of a future together; the more likely they are to last," explains Howard Markman, Ph.D., coauthor of Fighting for Your Marriage and a couples researcher at the University of Denver. So get started on your amore analysis and find out if you and lie have what it takes to experience lasting love...or if your differences are too overwhelming to overcome.

COMPATIBILITY CLINCHER 1

are you socially in sync?

The couple that parties together often stays together, because the way people naturally choose to socialize reflects their most basic path to happiness. "Everyone has a natural tendency toward either introversion or extroversion that defines how they destress and stay balanced," explains Marianne Dainton, Ph.D., associate professor of communication at La Salle University in Philadelphia. "When an outgoing person feels down or drained, she needs to be around other people to recharge. Shy people get that same effect from time alone."

If both you and your boy get energized out in a crowd-or the two of you are more content holing up at home-you're in luck. As the relationship progresses, you'll naturally enhance each other's mental health. But if one of you is supersocial and the other's a confirmed nester, there's a chance that the friction or constant compromising required to make plans could leave you both emotionally frazzled and seriously spent. "A gregarious partner may feel held back by a shy person, unable to get the social stimulation he or she needs," explains Dainton, "while a shyer person may never get the chance to recharge if dating an extrovert."

Janet, 28, learned that she belongs with a fellow party animal. "I was used to always trying to talk guys I dated into going out as much as I wanted to," she recalls. "But my current boyfriend is into going out almost every night, and I don't have to worry about whether he's having fun. The problem that caused the most fights in my previous relationships no longer exists!"