Book excerpt: With profound implications for our most foundational assumptions about gender, Gender Mosaic explains why there is no such thing as a male or female brain. For generations, we've been taught that women and men differ in profound and important ways. Women are more sensitive and emotional, whereas men are more aggressive and sexual, because this or that region in the brains of women is smaller or larger than in men, or because they have more or less of this or that hormone. This story seems to provide us with a neat biological explanation for much of what we encounter in day-to-day life. But is it true? According to neuroscientist Daphna Joel, it's not. And in Gender Mosaic, she sets forth a bold and compelling argument that debunks the notion of female and male brains. Drawing on the latest scientific evidence, including the groundbreaking results of her own studies, Dr. Joel explains that every human brain is a unique mixture -- or mosaic -- of "male" and "female" features, and that these mosaics don't map neatly into two categories. With urgent practical implications for the way we understand ourselves and the world around us, Gender Mosaic is a fascinating look at the science of gender, sex and the brain, and at how freeing ourselves from the gender binary can help us all reach our full human potential.