I read the book this guy wrote. It is awesome: Sex at Dawn: How We Mate, Why We Stray, and What It Means for Modern Relationships.
Reading the book you find your jaw sort of dropping and thinking, “Wow! That make so much sense and explains so much.”
I was reminded of this after Say Uncle pointed out Rick Santorum says he will fight the dangers of contraception—some people will want to have sex without any intention of had a child result from it. As a commenter pointed out, “I thought Ron Paul is supposed to be the kook…”