My problem with this talk is that he sets things up to explicitly argue against the idea that the pre-agricultural world was more harmonious, but the bulk of his arguments are about how things were worse in earlier agricultural times than now.

Godesky (on anthropik.com) states that "Keeley ignores the systematic violence of civilization: he lumps together all occasions of violence in 'primitive' societies, and compares them to our own wars, or our own homicide rates, but never the combination." Pinker's using Keeley's numbers, titles it "warfare" on the slide, but says it's about the rather different event of dying at the hands of another man. I'd have to research Keeley in more depth to judge what's going on here, but someone's not painting the picture true.

In any case, Pinker doesn't address the entirely dodgy nature of extrapolating these selective stats from contemporary hunter-gatherers to prehistory. I've been criticized a lot (sometimes rightly) for taking anthropological evidence about shamanic motifs and using them to interpret prehistoric art and monuments. I still think there's some use for this, but you need to be really careful.

Pinker is pretty careless. To use such contemporary figures - from, as Godesky has it, "post-apocalyptic" indigenous cultures, warped in some way at least by contact with agricultural societies - to be so categorical about the past is pretty suspect.

The evidence that we're not as barbaric as we were a millennia or two ago is pretty compelling. I just don't like the way this evidence is implicitly used to bolster the "general trend away from violence" argument that he uses to basically say hunter-gatherers are the worst of the worst.

Maybe the past few centuries have been about adjusting a bit to the catastrophic impact that agriculture had on human life?

Of course a lot of the advances of the past few centuries have been built on technological advances. But for a century or so general violence may well have been decreasing as there's plenty of cheap energy to go around. We fight over it still, but there's been plenty. As fossil fuels decline, the idea of an inexorable march towards peace might be challenged. Another can of worms there! But it's worth bearing in mind that if large scales of history are part of your argument, you have to take into account the fact that the story's not over yet - just to temper any arrogant, too-bold conclusions.

Some interesting points against Godesky's stuff. If you're bothered I'd recommend searching his site for his responses (he's usually quite thorough) and posting them in his comments if he's not addressed them...