In this book Simon Baron-Cohen outlines his theory that the differences between how men and women think, can be explained by their differing ability at empathising, and systemising. He gives a detailed description of how boys and girls behave from an early age and discusses possible biological causes. Although his theory is interesting it left me unconvinced. He gives lots of anecdotes and makes statements like, 'boys do better at test X, girls do better at test Y' but gives no statistics (although they are referenced). I suspect some of his ideas are controversial (for instance his suggestion that women are under-represented in the physical sciences as more men have a brain type suited to this work, is not supported by studies done inside the field). He does not offer any real evidence that autism is a case of an 'extreme male brain', and his idea that there may be a 'extreme female brain' comes across as pure speculation. He concludes the book nicely by discussing the limitations of this theory and the need for more research.