For this post, I get off easy, since FKM posted a nice post on the topic.
Check it out here:
http://fkmaniac.blogspot.com/2008/07/research-that-vindicates-issur-yichud.html
Basically, researchers found that when a man was alone with a woman, for a few min., his testosterone levels rose about 8% even if he did not find the woman attractive...