This title is shortlisted for the Samuel Johnson Prize 2012. This acclaimed book by Steven Pinker, author of "The Language Instinct" and "The Blank Slate", argues that, contrary to popular belief, humankind has become progressively less violent, over millenia and decades. Can violence really have declined? The images of conflict we see daily on our screens from around the world suggest this is an almost obscene claim to be making. Extraordinarily, however, Steven Pinker shows violence within and between societies - both murder and warfare - really has declined from prehistory to today.