In The Better Angels of our Nature, Pinker tries to do two things: convince the reader that society has gotten less and less violent over time, despite what the 11 o’clock news would like us to believe, and also explain why that might be the case. I don’t think he succeeds completely on the first count and he definitely does not hit the mark on the second.
When it comes to violence diminishing over the millenia, his case is quite tight (if, perhaps, surprising to some) when looking at overall trends. Despite the limitations of crime statistics in olden times, it seems clear that murders as well as less lethal violent acts such as child abuse or even rape decline — not necessarily smoothly, not necessarily for a given small area, but definitely in the aggregate. What’s less obvious (and, in my mind, not true) is that massive-scale events would not reverse the trend. Sure, the world has been peaceful (again overall, not in every geographic area) since WWII, but if we had another WWII, or worse, tomorrow, the lovely downward trends would suddenly shift. It would have been a suitable time to evoke the possibility of Black Swan events.
Assuming we are evolving to a less violent society, why is that? I suppose it’s always difficult to explain large-scale phenomena and Pinker struggles mightily to show that the “civilization process” is at work (when in doubt, invent a new word to explain the unexplainable?) And then he goes to the brain, of course! But since our brains probably have not changed much at all in the past few hundred years, it’s hard to follow the arguments without smirking. I dutifully smirked.