He's Gemini, I'm Scorpio. Each of us is the oldest child in our family of origin. Dr. Janice R. Levine, a clinical instructor in psychiatry at Harvard Medical School, co-edited a new book of essays by marriage and family experts on just that topic. But there's a real, physical chemistry underpinning the process. This chemical bath overpowers mind and body, and we can't resist.
Emotions are another top contributing factor.
Love also gives us purpose. And, of course, there is biology behind it all. Levine has been married 20 years, nearly as long as my 23 years of marriage. At some point in any relationship, you're no longer saturated by the chemical bath of pheromones, hormones, and brain enzymes 24-7. Remember your shared history and shared meaning, she says.