Whence War?

Two anthropologists in Finland argue that archaeological evidence from Europe, the Middle East, and western Asia shows that war originated only within the last 10,000 years, taking place more often as states grew and expanded, in the last 4,000 to 6,000 years. The theory has more than its share of critics, however: http://www.sciencenews.org/view/generic/id/351706/description/War_arose_recently_anthropologists_contend