In The Compatibility Gene, leading scientist Daniel M. Davis tells the story of the crucial genes that define our relationships, our health and our individuality. We each possess a similar set of around 25,000 human genes. Yet a tiny, distinctive cluster of these genes plays a disproportionately large part in how our bodies work. These few genes, argues Davis, hold the key to who we are as individuals and our relationship to the world: how we combat disease, how our brains are wired, how attractive we are, even how likely we are to reproduce. The Compatibility Gene follows the remarkable history of these genes' discovery.