Might we run an econometrics test on regime changes? The 17th century was much more violent than the preceding times, as was the early 19th century, albeit to a lesser extent. Perhaps the distribution is well-described by “long periods of increasing peace, punctuated by large upward leaps of violence”, as was suggested by Lewis Richardson in his 1960 book on the statistics of violent conflict? Imagine a warfare correlate to the Minsky Moment. In the meantime, there will be evidence of various “great moderations,” though each ends with a bang.
Pinker does discuss these ideas in detail in chapter five, but at the end of that section I am not sure why I should embrace his account rather than that of Richardson. I am reminded of the literature on the peso problem in finance.
Another hypothesis is to see modern violence as lower, especially in the private sphere, because the state is much more powerful. Could this book have been titled The Nationalization of Violence? But nationalization does not mean that violence goes away, especially at the most macro levels. In a variant on my point above, one way of describing the observed trend is “less frequent violent outbursts, but more deadlier outbursts when they come.” Both greater wealth (weapons are more destructive, and thus used less often, and there is a desire to preserve wealth) and the nationalization of violence point toward that pattern. That would help explain why the two World Wars, Stalin, Chairman Mao, and the Holocaust, all came not so long ago, despite a (supposed) trend toward greater peacefulness. Those are hard data points for Pinker to get around, no matter how he tries.
We now have a long period between major violent outbursts, but perhaps the next one will be a doozy.
How would this book sound if it were written in 1944? Maybe there is a regime break at 1945 or so, with nuclear weapons deserving the credit for a relative extreme of postwar peace. Pinker’s discussion of the nuclear question starts at p.268, but he underrates the power of nuclear weapons to reach the enemy leaders themselves and thus he does not convince me to dismiss the nuclear issue as central to the observed improvement, throw in Pax Americana if you like.
In one of the most original sections of the book (e.g., p.656), Pinker postulates the greater reach of reason, and the Flynn effect, working together, as moving people toward more peaceful attitudes. He postulates a kind of moral Flynn effect, whereby our increasing ability to abstract ourselves from particulars, and think scientifically, helps us increasingly identify with the point of view of others, leading to a boost in applied empathy. On p.661 there is an excellent mention of the wisdom of Garett Jones. Pinker’s thesis implies the novel conclusion that those skilled on the Ravens test have an especially easy time thinking about ethics in the properly cosmopolitan terms; I toy with such an idea in my own Create Your Own Economy.
What is the alternative hypothesis to this moral Flynn Effect? Given that the private returns to supporting violence are rare — most of the time — and violence has been nationalized, people will have incentives to invest in greater empathy and to build their self-images around such empathy. This empathy will be real rather than feigned, but it also will be fragile rather than based in a real shift in cognitive and emotive faculties; see 1990s Mostar and Sarajevo or for that matter Nagasaki or British or Belgian colonialism.
When doing the statistics, one key issue is how to measure violence. Pinker often favors “per capita” measures, but I am not so sure. I might prefer a weighted average of per capita and “absolute quantity of violence” measures. Killing six million Jews in the Holocaust is not, in my view, “half as violent” if global population is twice as high. Once you toss in the absolute measures with the per capita measures, the long-term trends are not nearly as favorable as Pinker suggests.
Here is John Gray’s (excessively hostile) review of Pinker. In my view this is very much a book worth reading and thinking about. And I very much hope Pinker is right. He has done everything possible to set my doubts to rest, but he has not (yet?) succeeded. I find it easiest to think that the changes of the last sixty years are real when I ponder nuclear weapons.