The Mathematics of Marriage, argues that a marriage can, in fact, be modeled by a surprisingly simple ensemble of differential equations. A Jordan Ellenberg review of the book in Slate provides an overview of the book and the world's shortest explanation of differential equations (for better or worse...)
"The theory's attractiveness is hard to deny. It neatly presents marriage as a process both mathematical and unpredictable, both stable and prone to catastrophe. Even the John Nash character in A Beautiful Mind would have to agree--'love is like that.'"
Thanks to John Derbyshire on NRO Corner.