We train soldiers for war. Let's train them to come home, too

Media focus, along with PTSD, can amplify our perceptions of violence. However, a careful look at the data shows that we humans have been growing progressively more peaceable. The most meticulous summary of this tempering of hostilities can be found in this book. Here Pinker details the decline in violence of nearly every variety — war, genocide, homicide, torture, child abuse and even cruelty to animals — from the epoch of foragers, across the ages, and into contemporary times. Several factors, argues Pinker, are driving our temperance, including increased literacy, nation-states securing monopolies on taking life and expanding commerce. The arc of Pinker’s story is vast, his message both hopeful and empirically driven and its content written with a clarity of mind possessed by few other contemporary scholars.

Humans evolved in closely knit social groups that ate, slept, loved and made war together. Today, closely shared combat experiences light up ancient parts of the brain that make men relish the interconnection of combat. But the resulting sense of belonging often bleeds away when veterans return from war to our modern, insular ways of living. Junger tackles this topic deftly, speaking through experiences with veterans he was embedded with Afghanistan, and asking important questions about what role social isolation plays in PTSD — and whether we need to rethink our nation's approach to caring for our veterans when they return from war.

Cantor's book is the first to explore PTSD within the framework of evolutionary psychiatry. He uses evolutionary science to explain PTSD as a set of adaptations for helping our ancestors survive dangerous environments — but one that becomes pathological when it fails to "turn off" outside the context of danger. This understanding can help to destigmatize PTSD, by reframing it as the brain doing exactly what it was designed to do, just in a different time and circumstance.

War and peace studies are regrettably incomplete if they fail to consider the role of our evolved psychology. Many fields offer proximate explanations for the machinations of war; evolutionary science offers the ultimate explanations, the "why" of our propensity to take arms against one another. Malcolm and Potts do a terrific job of synthesizing a body of emerging research, world history and the politics of sex to explain how men are driven to war by ancient evolutionary forces. The best way to avert PTSD would be to avert war, and works like this provide valuable insights toward this end.