" Society thinks of violent acts as manifestations of evil or immorality. We're told we have ultimate control over our own behavior, that each and every one of us has the free will to choose not to hurt another human being. But it's not just morality that guides us. Biology does as well. Our frontal lobs helps us integrate thoughts and actions. They help us weight the consequences of those actions. Without such control, we'd give in to every wild impulse. "

― Tess Gerritsen , The Apprentice (Rizzoli & Isles, #2)