We rely on science to tell us everything from what to eat to when and how long to exercise, but what about relationships? Is there a scientific explanation for why some relationships sail smoothly along while others are more like a storm tossed voyage?

In their book Attached: The New Science of Adult Attachment and How it Can Help You Find – and Keep -- Love, authors Amir Levine and Rachel S. F. Heller reveal how an understanding of adult attachment–the most advanced relationship science to date–can help us find and sustain love.

Attachment research designates three main "attachment styles," or manners in which people perceive and respond to intimacy in romantic relationships. Basically, "secure" people feel comfortable with intimacy and are usually warm and loving. "Anxious" people crave intimacy, are often preoccupied with their relationships and tend to worry about their partner’s ability to love them back. "Avoidant" people equate intimacy with a loss of independence and constantly try to minimize closeness.

Every person, whether he or she has just started dating someone or has been married for 40 years, falls into one of these categories. Understanding your own attachment style and that of you partner or prospective partner can radically change the way you perceive yourself, your partner and your relationship. For more details see "What Attachment Theory Can Teach about Love and Relationships", the cover story of the January/February 2011 issue of Scientific American Mind. Also see Attached: The New Science of Adult Attachment and How It Can Help You Find—and Keep—Love, by Amir Levine, M.D., and Rachel S. F. Heller, M.A. (Penguin Books).

To find out your attachment style and that of your partner, and to learn how compatible you are, take our attachment quiz.