Pinker, Steven. 2013. The Decline of War and Conceptions of Human Nature. International Studies Review 15, no. 3: 400-405.
Many observers are skeptical of the evidence that war has declined, because they think that a decline in war requires an unrealistic, romantic theory of human nature. In fact it is compatible with a hardheaded view of human violent inclinations which is firmly rooted in evolutionary biology. Homo sapiens evolved with violent tendencies, but they are triggered by particular circumstances; they are not a hydraulic urge that must periodically be discharged. And though our species evolved with motives that can erupt in violence, it also evolved motives that can inhibit violence, including self-control, empathy, a sense of fairness, and open-ended cognitive mechanisms that can devise technologies for reducing violence.
FAR 2013. Citation question: the assigned DOI refers to a collection of articles, only one of which is written by Pinker. I cited this part of the article only, which is what the author submitted, but it will not match the autofill for the DOI. Abstract from author's original, as the sub-article has no abstract.