Helen Fisher visits Google's Mountain View, CA headquarters to discuss her book "Why Him? Why Her?: Finding Real Love by Understanding Your Personality Type." This event took place on February 20, 2009, as part of the [email protected] series. In Why Him? Why Her?, Fisher unlocks the hidden code of desire and attachment. Each of us, it turns out, primarily express one of four broad personality types—Explorer, Builder, Director, or Negotiator—and each of these types is governed by different chemical systems in the brain. Driven by this biology, we are attracted to partners who both mirror and complement our own personality type. Based on entirely new research—including a detailed questionnaire completed by five million people in thirty-five countries—Why Him? Why Her? will change your understanding of why you love him or her and help you use nature's chemistry to find and keep your life partner. Fisher is one of the world's leading experts on the nature of romantic love and attachment. She is the chief scientific adviser to Chemistry.com, a division of Match.com. She is the author of four previous books, two of which—The First Sex and Anatomy of Love—were New York Times Notable Books. Fisher is a research professor of anthropology at Rutgers University. She lives in New York City.