This interview of a book's author sits here best IMHO, even if its focus is mass killing - which is part of savagery.

It starts with:
Abram de Swaan spent his first years of life in the Netherlands, witnessing the horrors of World War II. After dedicating decades to the study of human behavior, the award-winning sociologist was so struck by the 1994 Rwandan genocide’s eerie resemblance to the systematic killings of the Holocaust that he decided to investigate the roots of mass murder. De Swaan’s new book, The Killing Compartments: The Mentality of Mass Murder, peers deeply into the minds of those who carry out atrocities, seeking to understand the societal and psychological conditions that give rise to mass murder.
Link to the interview:http://nymag.com/scienceofus/2015/02...s-happen.html?

Link to the book:http://www.amazon.com/The-Killing-Co...tag=sciofus-20