The book is based upon four scientific principles. The first is the principle of human evolution. It was Darwin, in fact, who first suggested that a belief in gods might be a result of “structure of brain heredity.” The book uses modern neuroscience to fully develop Darwin’s original idea.The second principle is parallel evolution. This occurs when organisms that have had a common genetic origin continue to evolve along similar lines even though they have been separated from each other for thousands, or even millions, of years. The most famous example of parallel evolution are the mammals of Australia, many of which are remarkably similar to mammals on other continents despite the fact that Australia drifted away from other continents more than 100 million years ago. Parallel evolution explains not only why agriculture developed at about the same time independently at several places in the world, but also why gods emerged at about the same time independently at several places in the world.The third principle is the science governing the evolution and function of specific brain areas. For a century we have known which parts of the human brain evolved early and which parts evolved more recently. In recent years we also developed the technology to ascertain the function of specific brain areas. Thus we can now say with certainty that the motor cortex evolved very early, allowing a newborn child to hold on and suck, and the lateral prefrontal cortex evolved very recently, allowing humans to plan the future.The final principle on which the book is based is that the cognitive development of children roughly parallels the evolution of our species. Thus children develop an awareness of self at about age two, and only later develop an awareness of what others are thinking, an understanding of death, etc. We can therefore use our knowledge of child development to make some informed guesses regarding the order of development of cognitive processes in human evolution.My education and professional training led me to this book. As a university student I majored in religion. I then got a master’s degree in anthropology and worked for two years in Africa, thus experiencing other cultures. My training in medicine and psychiatry led me to focus on the brain, and I organized one of the most widely used brain collections for research. Evolving Brains, Emerging Gods is the composite result of those experiences.