'A riveting ride through your own brain' - Adam Grant, New York Times bestselling author of Originals WINNER of the Society for Personality and Social Psychology's book prize for 'The Promotion of Social and Personality Science' If humans are fundamentally good, why do we engage in acts of great cruelty? If we are evil, why do we sometimes help others at a cost to ourselves? Whether humans are good or evil is a question that has plagued philosophers and scientists for as long as there have been philosophers and scientists. Many argue that we are fundamentally selfish, and only the rules and laws of our societies and our own relentless efforts of will can save us from ourselves. But is this really true? Abigail Marsh is a social neuroscientist who has closely studied the brains of both the worst and the best among us-from children with psychopathic traits whose families live in fear of them, to adult altruists who have given their own kidneys to strangers. Her groundbreaking findings suggest a possibility that is more optimistic than the dominant view. Humans are not good or evil, but are equally (and fundamentally) capable of good and evil. In The Fear Factor Marsh explores the human capacity for caring, drawing on cutting edge research findings from clinical, translational and brain imaging investigations on the nature of empathy, altruism, and aggression and brings us closer to understanding the basis of humans' social nature. 'You won't be able to put it down' - Daniel Gilbert, New York Times bestselling author of Stumbling on Happiness '[It] reads like a thriller... One of the most mind-opening books I have read in years' - Matthieu Ricard, author of Altruism

In this compelling scientific detective story, a leading neuroscientist looks for the nature of human kindness in the brains of heroes and psychopaths (Wall Street Journal). At fourteen, Amber could boast of killing her guinea pig, threatening to burn down her home, and seducing men in exchange for gifts. She used the tools she had available to get what she wanted, and, she didn't care about the damage she inflicted. A few miles away, Lenny Skutnik was so concerned about the life of a drowning woman that he jumped into the ice-cold river to save her. How could Amber care so little about others' lives, while Lenny cared so much? Abigail Marsh studied the brains of both psychopathic children and extreme altruists and found that the answer lies in our ability to recognize others' fear. And as The Fear Factor argues, by studying people who demonstrate heroic and evil behaviors, we can learn more about how human morality is coded in the brain. A path-breaking read, The Fear Factor is essential for anyone seeking to understand the heights and depths of human nature.