Many data sets show that rates of violence have gone down over the course of history.

True if many separate datasets (e.g. homicide records, war-death series, data on executions, torture, and other violence) show long-term declines in rates of violence over history, as assessed in the literature up to 2018. Mostly true if many datasets show declines but some of them or how they are read are significantly contested. Mixed if the datasets are roughly split or the decline appears only in some periods or types of violence. Mostly false if only a few datasets support a long-term decline and others contradict it, so the general claim overstates narrow evidence. False if the data broadly show no decline or an increase.

Set before the research began.

1. E1 Modernization, Self‐Control and Lethal Violence. The Long‐term Dynamics of European Homicide Rates in Theoretical Perspective British Journal of Criminology (Manuel Eisner), reproduced on SciSpace · 2001

   “have declined in Europe over several centuries.”

2. E2 Hard numbers? The long-term decline in violence reassessed ... Empirical objections and fresh perspectives Continuity and Change (Cambridge University Press) · 2021

   “However, the data underpinning the decline of violence thesis has not been subjected to a satisfactory level of critical scrutiny. Our re-analysis of the source material will show that the data is far less reliable than is often suggested.”

3. E3 Has violence declined, when large-scale atrocities are systematically included? - The GiveWell Blog GiveWell · 8 July 2015

   “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.”

4. E4 Has violence declined, when large-scale atrocities are systematically included? - The GiveWell Blog GiveWell · 8 July 2015

   “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.”

Eisner's criminology study (E1) finds that homicide rates "have declined in Europe over several centuries", which supports a long-term decline in at least one major type of violence. GiveWell's independent 2015 review (E3, E4) concludes that the big-picture decline "stands overall". It adds that large-scale atrocities partly offset the decline, and says a net decline is likely "but it isn't clear". A 2021 reassessment (E2) argues that the data behind the decline thesis is less reliable than often suggested. Together these sources show that the decline is supported but its reading is significantly contested, which fits "mostly true" under the criteria.