Many people say long-distance love does not last. But research tells a different story. A study in the United States looked at about 870 people in relationships. Couples who lived far apart were often just as happy, or even happier, than couples who lived close. Their breakup rate was about the same.

But there is one danger. When couples start living near each other, they may find their partner is not perfect.

Moving away for school or work often leads to a long-distance relationship, and many people expect it to fail. However, a national survey of about 870 Americans in relationships found that long-distance partners rated their relationship quality higher in some ways and felt more committed than partners living close together. Their breakup rates were about the same.

Another study asked couples to record their daily communication. Long-distance couples shared their true feelings more deeply and saw their partners in a more idealized way, which increased intimacy. But idealization has a risk. A different study found that some long-distance couples broke up soon after they started living near each other, especially when they had been apart for a long time.

Couples who live far apart are often told their relationship will not last. A 2013 analysis of a nationally representative sample of about 870 Americans found little to support that warning. Compared with couples living near each other, long-distance partners reported higher relationship quality in several respects, stronger dedication and less of a sense of being trapped, and at follow-up they had broken up at similar rates.

A diary study offers one reason. Partners who were apart disclosed more about themselves through calls and messages and saw each other in a more positive light. Both habits increased intimacy. That rosy view has a cost, though. In research with university students, long-distance couples were fairly stable while separated, but breakups became more common once they moved near each other.

The longer the separation and the more partners had idealized each other, the more likely the relationship was to wobble when everyday flaws came into view. There is also a selection problem that surveys cannot easily rule out. Couples who choose to stay together across a distance may have differed from other couples from the start. For couples about to close the gap, it helps to expect a partner with ordinary flaws.