Why do we need sex? Looking back into our evolutionary past, Dr. Sharon Moalem explores the ways in which the struggle to survive and create healthy offspring has determined -- and continues to determine -- our sexuality. From ground-breaking research to strange and fascinating discoveries to an exploration of the roles of culture, biology, and time on sexuality, How Sex Works is an entertaining and comprehensive history of sex that goes far beyond our classic "birds and bees" approach.

I'm so excited and I just can't hide it

Millions of words -- in books and on blogs, in magazine articles and advice columns -- have been written about mastering the search for Ms. or Mr. Right. And millions of people have wondered why they keep dating the wrong man or woman when they think they know what's really good for them. They think they know what they need; the problem is, what they need isn't always what they want.

So why do we want what we want anyway? How much of what turns us on is hardwired?

Like everything else, attraction and arousal (and possibly love, for that matter) are the products of millions of years of finely tuned biological engineering. And there's really only one goal behind the engineering -- to get you to have sex.

As you'll see, much of what we are pre-programmed to find attractive may be connected to what it tells us about health, fertility, and compatibility of potential mates. Genetic compatibility, that is. Nature isn't really concerned about similar political views or favorite movies, although it does place stock in appearances. From the standpoint of survival, in some sense it really cares that we have strong offspring, and that they get what they need to grow up and give us grandkids in turn. But genetic compatibility only gets us halfway there in terms of successful offspring -- it can give us healthy babies, but those babies need parents to protect and nurture them into maturity. And that's where love comes in. Falling and staying in love -- the pair bonding that keeps a couple together long enough to have, raise, and care for children -- almost certainly involves chemical processes that are a product of millions of years of evolution.

Continued...