If you, the reader, were thumbing through Making Monsters in a bookstore, I hope that you would first glance at the preface, which begins with the testimony of a man who was a perpetrator in the 1994 Rwanda genocide. He reported that during the genocide, he and his fellow genocidaires literally did not consider the Tutsis whom they hacked to death as human beings. “I cannot explain it.” he said, “The only answer I can give is that it was like being in a fog, something like a darkness.”After the Preface, it would be great if you flip forward a few pages to read the account of the lynching of Henry Smith, a cognitively disabled Black man who was murdered by a White mob in 1893. Like many other Black men, Smith was tortured before being killed. Red-hot pokers were moved up and down his body, and his eyes were burned out. Then he was placed on a mound of cotton husks and slowly burned to death, as thousands of spectators looked on. And once the flames died down and what was left of his body cooled, members of the crowd pressed in to acquire pieces of Smith’s charred corpse as souvenirs. Many lynchings of Black men were large, festive events like this, that were openly advertised and covered by the media of the day. They were sometimes even referred to as “barbecues.” Reading a bit further, the bookstore browser will see that the press often described these men as vicious, subhuman beasts—as monsters, brutes, and fiends.The Holocaust has become almost synonymous with exterminationist dehumanization. However, many people are unaware that Nazi ideology often represented Jewish people as literally demonic, and that Nazis believed that they were engaged in a life-and-death struggle with these Untermenschen (subhumans). So, I would love you to turn to page 39, and learn that Hitler claimed, “The Jews are undoubtedly a race, but not human….” and then gander at Chapter Ten, which surveys the dehumanization of European Jews from the Middle Ages to the Third Reich and beyond.I would like you to start with these segments, because they succinctly drive home the reality of dehumanization and its terrible consequences, and will hopefully make you want to engage more deeply with the book.As is evident from everything that I have said, dehumanization is an immensely destructive force. At any given moment, including the moment that I am writing these words and you are reading them, there is some place in the world where dehumanizing rhetoric is fanning the flames of violence. It is easy to imagine that you are not vulnerable to such rhetoric, and that if you had been a German citizen in 1942 or a Rwandan Hutu in 1994, you would not have supported much less perpetrated atrocities. If you think this, I hope that reading Making Monsters will cause you to revise your views. The psychological dispositions that underpin dehumanization are pervasive and powerful, and none of us should assume that we are immune to them.The looming threat of catastrophic climate change makes understanding dehumanization especially urgent. There is no doubt that global warming will have huge social and political consequences. There will be vast numbers of people seeking refuge as areas of the world become uninhabitable for them. The gap between haves and have-nots will widen precipitously, infrastructures will collapse and centers of power will shift. These conditions are a perfect storm for the proliferation of the most dangerous kinds of dehumanizing beliefs, and the horrific acts that so often flow from them.