"Compatibility does not hinge on some personal inventory of traits. Compatibility isn't something you have. It's something you make. It's a process, one that you negotiate as you go along. Again and again. It's a disposition, an attitude, a willingness to work.
I recently asked myself: What would social science have to say to a matchmaker? Damn little. Measures of personality don't predict anything, but how people interact does. Couples need to feel they are building something together that has meaning. How does a relationship support what you see as a mission in life? This is the existential part. You must also connect emotionally. How much do you respond to each other's bids for attention? Does your partner turn toward you with equal enthusiasm? You need to ask questions and constantly update your knowledge of one another. And you need the ability to hear your partner's delight and take it in.
In my own practice, those who weather the kid-storm tend to differ from those who are swept away in one important respect: the couples who seem happiest after children have worked hard to improve themselves."