One of the most common reasons people choose the wrong partner is that they don't really know themselves. (It's nearly impossible to find someone capable of understanding and respecting your deepest vulnerabilities when you aren't clear about them, either.) We can become infatuated with a mate for a variety of reasons and idealize that person for months or even years. But eventually the incompatibilities become apparent, and we may fall out of love. In fact, it's often the qualities that attracted us in the first place that ultimately drive us away.
Identifying your relationship values—the ones that could lead to lasting love—is the first, crucial step toward finding someone who shares them. As early as the first few dates, you'll see clues that indicate those values. Does he look into your eyes, sit close to you, take your arm? This kind of contact signals confidence and a need for connection, both of which bode well for a passionate relationship. Does he comment on your appearance? (A sign that he appreciates affirmation.) When you talk about a dilemma, does he sympathize? (A show of emotional support.) Do you go on interesting, creative dates? (Spontaneity.) Does he talk about his ex-partners with respect? Is he reliable? Does he consistently think about you when making decisions? (All measures of trustworthiness.)
How he manages unexpected stressors (even something as minor as a mishandled restaurant reservation) can hint at his ability to communicate. The depth of his conversation can reveal his need for companionship. And his willingness to do favors for friends and colleagues can indicate his ability to be a team player.
When you find yourself falling for someone new, try to look beyond the traits that seem sexiest at the moment (his charm, for instance, or ambition, or love of travel). Ask yourself: Are the qualities that I most admire in this person very different from my own? If so, they might not seem as appealing in two years. Choose a mate for the traits that will make him a good partner now and down the road.