Salter and co-authors Franklin Mixon of Columbus State University and Ernest King of the University of Southern Mississippi asked 402 people to rate agents, both male and female, on a scale of 1 to 10, from very unattractive to very attractive, based on online head shots.

WSJ: In Real Estate, Looks Can Sell

To further complicate things the test results are not just either male or female, they can be on a sliding scale between the two.

BBC: Male or female? Babies born on the sliding sex scale

On a smaller scale, 16% of my incoming class at Chicago Booth was female.

FORBES: Why I Like The Odds On Being A Woman In Business