University of British Columbia psychopathy expert Leanne ten Brinke draws on the latest science to help you identify and manage dark personalities—from the difficult to the deadly—and dramatically reduce their impact on your relationships, workplaces, and society at large.

Everyone knows how much damage one bad apple can do. One bully in a classroom can create a culture of fear. A controlling spouse can crush an entire family’s sense of stability, security, and independence. A domineering boss can tank a team’s performance. A ruthless, shameless politician can set a whole country on edge. But who are these poisonous people? How much harm and misery do they really cause? And what can the rest of us do to stop them from ruining our homes, workplaces, and communities?

In Poisonous People, award-winning researcher Dr. Leanne ten Brinke offers a brilliant new perspective on dark personalities. Weaving together personal stories and pathbreaking research, she depicts a surprising reality: a small portion of the population causes most of the world’s suffering. People with psychopathic and related personality traits commit a disproportionate amount of crime, with an economic cost estimated in the trillions of dollars. They also poison communities by spreading negativity, violating trust, and eroding norms. Fortunately, science offers powerful solutions. By understanding the harm dark personalities cause, identifying them when we see them, making informed decisions about whether to exit relationships with them, and knowing how to manage them when we decide to stay, we can dramatically reduce the pain we and others around us suffer.

In Poisonous People, ten Brinke gives us powerful, science-based tools for navigating dark personalities in a range of everyday contexts. As she argues, we have the power to reduce their power over us, whether at home, at school, at work—even in the political realm. Poisonous People shows us how to use that power to improve our lives—and the world.