“Marriage emerged some forty-five hundred years ago and evolved into a widespread and accepted institution that bonded families, maintained order, and created wealth. Unlike today, where many of us are searching for our romantic "soul mate," marriage was originally more about economics than deep emotion.”
Source : Robi Ludwig, Matt Birkbeck (2006). “'Till Death Do Us Part: Love, Marriage, and the Mind of the Killer Spouse”, p.1, Simon and Schuster