It's a theme that appears in thousands of movies, books and musicals: Boy meets girl. They fall in love, marry and live happily ever after. Soul mates forever. Fully two-thirds of Americans believe in the concept of soul mates, where "two people are destined to be together," according to a recent Marist Poll. But a new study offers an important reality check about unions formed in a whirlwind of passion. "Soul mate" couples are often happy at first, because they have intense emotional and personal connections, said W. Bradford Wilcox, lead author of the article in the Sept. 1 issue...