Drop a rock. It falls and hits the ground. Once you understand brain evolution, many of our behaviors will become more predictable. To a scary degree, we are reactive animals ruled by passions, and not the rational geniuses with free will that we like to imagine. First the bad news: The notion that people make decisions and choices to maximize objective self-interest has been demolished. People are not rational - far from it. Now the good news: We are finding out exactly how and why we act in these seemingly irrational ways. In other words, there is a method to our seeming madness. We evolved for a particular environment, but our rapid social advances and mushrooming populations have created a bewildering new world. On the timescale of this dizzying change, evolution has effectively stopped, and we must rely on what has gotten us this far. By retracing the path that our distant ancestors took to get here, we can understand the stunning abilities and glaring weaknesses which we have inherited. Sometimes our reactions and responses are appropriate and uncannily helpful. In the blink of an eye we can assess complex situations and reach critical life-or-death decisions. At other times, we are seemingly our own worst enemies - repeating the same mistakes, even when we know the results will be counterproductive, or even deadly. Unlocking the true nature of the human brain is the last frontier. Recent work in fields such as biology, neuroscience, evolutionary psychology, medical imaging, social science, and behavioral economics is combining to show us the inner workings of this evolutionary marvel. This book is designed for you - the curious and intelligent searcher for truth.