you can empirically find defeated populations in the genetic code of the descendants of the winners
You lost me there. Why is that relevant?
This allows you to find empirical examples of ethnic groups that were successfully repressed by killing all the males -- even if you don't have e.g. literary sources. This has bearings on how popular and how successful repressions by kill-them-all methods were.
Here's my op-ed that uses long-term orientation, probabilistic thinking, numeracy, consider the alternative, reaching our actual goals, avoiding intuitive emotional reactions and attention bias, and other rationality techniques to suggest more rational responses to the Paris attacks and the ISIS threat. It's published in the Sunday edition of The Plain Dealer, a major newspaper (16th in the US). This is part of my broader project, Intentional Insights, of conveying rational thinking, including about politics, to a broad audience to raise the sanity waterline.