Why are some people die-hard liberals and others hardcore conservatives? Why are we always hopeful for solutions even in the darkest times - and so good at figuring them out? The answer is found in a single chemical in your brain: dopamine. Dopamine ensured the survival of early man. Thousands of years later, it is the source of our most basic behaviors and cultural ideas-and progress itself. Dopamine is the chemical of desire that always asks for more-more stuff, more stimulation, and more surprises. In pursuit of these things, it is undeterred by emotion, fear, or morality.