I was reading a Digg thread about why trophy wives are less popular these days, and I stumbled on a reference to Ladder Theory (original source). In case you are not familiar with it, here's the introductory paragraph on the topic from LadderTheory.com:
The ladder theory is a funny, scientific explanation of how men and women are attracted to each other. It also covers such topics as why women sometimes just want to be friends but men always want sex. It is based upon many years of sociological field testing, and was first conceptualized in 1994 in Exeter, CA by Dallas Lynn with acknowledgments to Jared Whitson for his role in formalizing the theory.
There's an entire Ladder Wiki dedicated to the topic as well.