Attraction, Love, SexSex, after hunger, may be the most powerful motivating force in our lives. It drives us to seek intimate contact with others and to form relationships that may be fleeting or lifelong, blissful or troubled. Yet many mysteries surround sex and sexuality: Why don't we reproduce by virgin birth? Why does so much of our sexual behaviour have nothing to do with reproduction? Why isn't everyone heterosexual? How does the brain create sexual arousal? How do