Book excerpt: We all know the opposite sex can be a baffling, even infuriating, species. Why do most men use the phone to exchange information rather than have a chat? Why do women love talking about relationships and feelings with their girlfriends while men seem drawn to computer games, new gadgets, or the latest sports scores? Does it really all just come down to our upbringing? In The Essential Difference, leading psychologist Simon Baron-Cohen confirms what most of us had suspected all along: that male and female brains are different. This groundbreaking and controversial study reveals the scientific evidence (present even in one-day-old babies) that proves that female-type brains are better at empathizing and communicating, while male brains are stronger at understanding and building systems-not just computers and machinery, but abstract systems such as politics and music. Most revolutionary of all, The Essential Difference also puts forward the compelling new theory that autism (and its close relative, Asperger's Syndrome) is actually an example of the extreme male brain. His theory can explain why those who live with this condition are brilliant at analyzing the most complex systems yet cannot relate to the emotional lives of those with whom they live. Understanding our essential difference, Baron-Cohen concludes, may help us not only make sense of our partners' foibles, but also solve one of the most mysterious scientific riddles of our time.