The Better Angels of Our Nature takes a thesis I would love to believe; indeed, have casually believed for most of my life. It is that humans have grown less horrible with time. The 20th century, the century of Hitler, Stalin and Pol Pot, of Mao in China and Mobutu in the Congo, was appalling, but the number of deaths by violence as a proportion of the total population remained modest compared with the ferocious cruelties of the wars of religion in the 17th century. The modern nation state - the Leviathan of the philosopher Hobbes - has had a civilising effect almost everywhere. Education has helped, as has the empowerment of women, and the idea, too, of human rights. Within the epic sweep of history from ice age hunter gatherers to modern suburban householders, [author Steven] Pinker examines both the big picture and the fine detail, with surprises on every page. Overall ... he finds examples of falling murder rates everywhere (including among male English aristocrats 1330-1829). Murder rates as a percentage of population were far higher among the supposedly peace-loving and cooperative hunter-gatherer communities - the Inuit of the Arctic, for instance, the !Kung of the Kalahari and the Semai of Malaysia - than in the trigger-happy US in its most violent decade. Unexpectedly, deaths in warfare, once again as a percentage of total population, were far higher among the Gran Valley Dani of New Guinea, or in Fiji in the 1860s, than in Germany in the whole of the 20th century.