Note: I wrote the following on my personal time, then cleaned it up slightly for public consumption. This post is not directly related to GiveWell’s work, but we thought readers might find it interesting anyway. It provides a simple supplementary analysis to the argument presented in The Better Angels Of Our Nature that violence has declined over time. I conclude that the book’s big-picture point stands overall, but my analysis complicates the picture, implying that declines in deaths from everyday violence have been significantly (though probably not fully) offset by higher risks of large-scale, extreme sources of violence such as world wars and oppressive regimes.
Thanks to Steven Pinker for reviewing a draft of this post.
One of my favorite nonfiction books is The Better Angels of our Nature by Steven Pinker. It argues that “violence has declined over long stretches of time, and today we may be living in the most peaceable era in our species’ existence … it is an unmistakable development, visible on scales from millennia to years, from the waging of wars to the spanking of children.” For the most part, I think the book is quite convincing on this point.
This post focuses on what I see as the biggest missing piece of its analysis. The major large-scale atrocities of the 20th century – particularly the two World Wars and the regimes of Josef Stalin and Mao Zedong – stand as an obvious challenge to the book’s theme of declining violence over time. Better Angels does address these events, arguing that they are not as historically anomalous as they may seem. However, the book does not give a comprehensive, quantified picture of how recent centuries compare to older ones in terms of total deaths from such large-scale atrocities. It also does not compare the relative death toll of large-scale atrocities to that of other sources of violent deaths it discusses (homicide, witch hunts, executions, etc.) to determine whether the atrocities of the 20th century were violent enough to offset other kinds of improvements. While many critics have highlighted the atrocities of the 20th century, I don’t believe any of them have done this sort of analysis either, with the exception of a partial analysis on the Uncommon Descent blog.
Using some of the data cited in Better Angels, I’ve done a simple analysis to lay out estimated “deaths from major atrocities” for each century, going back to the 5th century BC. I’ve also looked a bit into how these figures would look if we included deaths from everyday violence as well. Having done this, four points stand out:
- There are two other centuries (13th and 17th) that look to have been at least as bloody as the 20th, though this observation is very sensitive to very imprecise death toll estimates of a very small number of atrocities. (“Bloody” here refers to high violent deaths per capita per year; “atrocity” means an enormous large-scale mass killing, like a war or conquest or democide.) The 13th century death toll comes almost entirely from estimates of the damage done by Genghis Khan, while the 17th century death toll comes mostly from estimates about the fall of the Ming Dynasty. I don’t see a clear trend overall on “death risk from large-scale atrocities” from the 13th through 20th centuries.
- Prior to the 13th century, it looks like per-century death tolls from the largest atrocities were consistently lower, and I doubt that this is an artifact of the data.
- Around the 15th century, a documented fall in the homicide rate seems to have started. The homicide rate decline and the rise in deaths from very large-scale atrocities that took place between the 13th and 15th centuries seem to be in the same ballpark as each other, consistent with the idea that violence shifted from individuals to regimes. I would guess that the net effect was a decline in violent deaths, especially when bearing certain issues with the data in mind, but it isn’t clear.
- Large-scale atrocities account for enormous numbers of violent deaths. While Better Angels describes multiple trends, it does not compare them to each other in an apples-to-apples way. My sense is that large-scale atrocities account for far more violent deaths than most of the other sources of violence the book discusses – so the lack of a positive trend means that the overall global risk of dying from violence may not have improved greatly over time (though it probably has improved). To make this point vivid, the global rate of violent deaths from the “big four” atrocities alone (two World Wars, regimes of Josef Stalin and Mao Zedong) – spread out over the entire 20th century – is ~50 violent deaths per 100,000 people per year; that’s comparable to the very worst national homicide rates seen today, whereas the homicide rate for high-income countries such as the U.S. tends to be less than 1/10 as high. In other words, the two World Wars + Stalin and Mao alone were enough to make the 20th century as a whole more dangerous than homicide makes today’s homicide-heaviest countries, and they were enough to offset the benefit of the European homicide rate decline that Better Angels describes from Medieval times through the Enlightenment.
Looking purely at quantified violent death risk by century, the picture that emerges from these figures is one of falling everyday violence that is significantly (though probably not fully) offset by higher risks of large-scale, extreme sources of violence such as world wars and oppressive regimes. The net impact is probably lower levels of violence, but it’s not entirely clear. The key transition looks like it was around the 13th-15th centuries; I don’t see much reason to think that the Scientific Revolution should bear much blame for rising atrocity tolls (the timing doesn’t work), but the “rule of law and rising power of governments” dynamic that Better Angels credits for much of the decline in everyday violence could be argued to have had a significant cost in terms of rare mass atrocities.
The dynamics of violent deaths discussed above are consistent with a picture of modernization as improvement in everyday conditions, accompanied by larger rare catastrophic events. This picture can be applied to more recent times as well, even as death tolls from atrocities have fallen: everyday peacefulness has continued to improve, but the potential maximum damage of global catastrophic risks (such as power grid failures, natural and engineered pandemics, climate change and artificial intelligence) seems to be on the rise as well. Today, the potential bad news is even more unlikely and infrequent, but potentially even more enormous, than ever before.
Taking a more holistic view – looking at ways in which non-fatal violence has declined, the phenomenon of the “long peace” since the mid-20th century, and other improvements over time – I think it remains the case that the modern world has become greatly less violent, as well as a better place to live in other ways. I do think that the overall point of Better Angels stands with my analysis in mind, though there is some added complexity to it.
Finally, I note that the literature on this topic appears extremely thin. Steven Pinker is not a historian, yet I believe his systematic examination of historical trends in violence is the first of its kind. Many critics of Better Angels highlight the question of how 20th century atrocities compared to past atrocities. However, I’ve seen only one critic who did either of the following: (a) spelled out a more systematic comparison Pinker could have done; (b) performed a rough version of this comparison. This critic was Uncommon Descent, a blog whose main purpose appears to be arguing for Intelligent Design.
Details follow. From this point on I abbreviate Better Angels as BA.
- I go through BA’s discussion of the major atrocities of the 20th century, and discuss why I believe more analysis is called for. BA’s argument and the need for more analysis
- I discuss my own rough attempt to make these comparisons, and what it shows: a lack of clear trend in deaths from large-scale atrocities from the 13th through 20th centuries, a smaller death toll from large atrocities but a higher toll from homicides prior to the 15th century, and the relative importance of large-scale atrocities vs. other sources of violence. More: My analysis
- I reflect on how one should think about long-term historical trends in violence and quality of life with these corrections in mind. Reflections