Love is magic. Our palms get sweaty, our knees get weak. That's true. But it is also a chemical reaction steeped in the basic needs of primitive man. Anthropologists dissect this emotion to its core: lust, romantic love and attachment. How we are aroused is explored: smell and tone of voice play into attraction and compatibility. Ever wonder why teens react so deeply to love? What is a "love map"? Peel back the layers of the most profound expression of our humanity.