At last, leading psychologist Simon Baron-Cohen confirms what most of us have long suspected: male and female brains are different. This groundbreaking and controversial study reveals the scientific evidence (present even in one-day-old babies) that proves female 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 the related condition of Asperger Syndrome) is actually an example of the extreme male brain, leaving those with the condition able to analyze the most complex systems but unable to relate to others' emotional lives. Understanding our essential difference, Simon Baron-Cohen concludes, may help us not just to make sense of our partners' foibles, but to solve one of the most mysterious scientific riddles of our time.