If we were asked, as an exercise, to craft a personal ad detailing what we were looking for in a partner, it may read something like this: Seeking someone who is kind and patient, independent yet loving, laid back, yet energetic. Someone who is confident, but isn’t afraid to laugh at him- or herself. Someone attractive, but down to earth. Someone who is up for anything, but knows what he or she wants. What we wind up finding in a partner can look very different. This may be a better ad: Seeking someone who is moody and unpredictable; aloof, yet jealous; low energy, yet temperamental. Someone who has low s elf-esteem, and no sense of humor when it comes to his or her flaws. Someone who concentrates too much on his or her appearance and often feels insecure. Someone who likes to control the situation and changes his or her mind about goals for themselves and their relationships. When it comes to how we behave in our relationships, a person can rarely be reduced to the black-and-whit...