"This book is about you, what you are, and how you got here," declares psychologist Thomas Suddendorf in this multi-disciplinary exploration of what separates humans from other animals. Focusing on the brain, Suddendorf identifies six areas of mental ability -- language, mental time travel, mind reading, intelligence, culture, and morality -- and explains how "the gap" derives from human aptitude for nested scenario-building and the need to connect. For example, while animals communicate, humans have language; and where animals demonstrate problem-solving abilities, humans possess the capacity for abstract reasoning. Why the gap? Well, according to Suddendorf, we probably widened it by driving our closest hominid relatives to extinction (but that's another story).