Simon Baren-Cohen's research kicks all sorts of ass. "Zero Degrees of Empathy" is a great read.
His Empathy Quotient is meant to be a scale on how "dual-minded" or empathetic one is. It's morphed into part of a larger Emphathizing-systemizing framework. More rough information on E-S can be found here.
Here's a test based on his Empathy Quotient. The test itself seems less impressive than his research overall, but.. I dunno, it's a test, and we like our tests.
I scored 67.