If you were lost in the desert and could have only one thing, what would you choose: a jug of clean water or a wide-screen, top-of-the-line plasma HDTV? If you were on a wilderness mountain top away from civilization, and you could have only one thing, what would you choose: a warm jacket or a great novel? Clearly, the need dictates the choice. Although you might want the latest TV or a good book, thirst and your need for warmth dictate that you choose the water and the coat. A natural hierarchy of needs emerges that guides us to make the right choices. Sometimes we align with biology, sometimes we don’t. In the end, biology rules.