Human Nature's Pathologist

 Stephen Pinker is a psychologist at Harvard University who is an expert in language. His recently published book, Better Angels of Our Nature, argues that violence has fallen drastically over thousands of years due to our the evolution of our brains to generate a wide range of responses to their environment. This may seem shocking, but he proves it to be true considering homicide rates, war casualties, and other measures as well. He relates this to the evolutionary psychology of our evolved brains. The article goes on to talk about his career in studying human language, and how it was produced by natural selection.

http://www.nytimes.com/2011/11/29/science/human-natures-pathologist.html?pagewanted=3&_r=1&ref=profilesinscience