The publisher provided the following excerpt of "Why Him? Why Her?: Finding Real Love by Understanding Your Personality Type," by Helen Fisher, to ABC News.
Watch an hour on the science of attraction Friday on a special edition of "20/20" at 9 p.m. ET
"I am large, I contain multitudes." -- Walt Whitman
"Now you will feel no rain, for each of you will be shelter to the other. Now you will feel no cold, for each of you will be warmth to the other. Now there is no more loneliness for you. But there is one life before you. Go now to your dwelling place, to eat to your days together. And may your days be very long upon this earth."
The Apache Indians of the American Southwest probably recited this wedding poem for centuries before I heard it in La Jolla, California, in 2006. It was an early June evening, the sky still pink and blue, the sea smells wafting through the windows as I sat in a folding chair on the second story of a fancy Italian restaurant. An older gentleman was conducting a short wedding ceremony, one mixed with rituals from the Christian, Jewish and Apache traditions. And before me glowed the two celebrants, Patrick and Suzanne -- one of the first couples to marry after meeting on the Internet dating site I had helped to design, Chemistry.com.
Patrick had been a journalist in New Orleans until he lost his job, his home and all of his belongings to Hurricane Katrina in 2005. West he went, taking up residence with relatives in Los Angeles in February 2006. Days after settling in, he joined Chemistry.com and received his first recommended match: Suzanne, a lawyer living in La Jolla. That first night they talked for three hours on the phone. They met the following weekend and fell passionately in love.
So on a balmy evening during an April vacation together in Paris, Patrick took her to the top of the Eiffel Tower and proposed. The dazzled young woman grinned her "yes." So here I sat at a fancy Italian restaurant in La Jolla, surrounded by some fifty of their friends and relatives on this festive wedding eve.
I like being around people who are in love. They have a contagious energy. This force was palpable in the groom, the first to arrive for the nuptials. He burst into the room, filling it with his vivacious charm. Although we had never met, he greeted me warmly. We instantly struck up a conversation about the evolution of the English language, his experience as a journalist in some dangerous parts of Asia and some of my past work on the brain chemistry of romantic love.
Others soon arrived, and we took our places on the folding chairs facing a small bar strewn with lilies. Last came the bride. I was stunned when saw her -- a tiny, perfectly formed, porcelain-like doll, with huge blue eyes and long auburn hair in soft ringlets wreathed in forget-me-nots. Like the mythological Helen, Suzanne had a face that could launch a thousand ships. And her vigor matched his. She was enraptured by her prince, gazing at him and grinning with uncontainable effervescence as she said "I do."