This excerpt comes from the book "The Science of Evil: On Empathy and the Origins of Cruelty" by Simon Baron-Cohen, which attempts to redefine "evil" in scientific terms as a lack of empathy. The author explores the concept of empathy as a measurable spectrum, developing the Empathy Quotient (EQ), and discusses how extremely low empathy, or "zero degrees of empathy," can manifest in different Zero-Negative subtypes, specifically psychopaths (Type P), narcissists (Type N), and borderlines (Type B). Conversely, the text also introduces the concept of Zero-Positive individuals, such as those with Asperger Syndrome, who lack empathy but are characterized by an extreme drive to systemize patterns. Finally, the text examines the biological and environmental factors contributing to empathy levels, including the role of genetics (twin studies), brain circuitry, and early childhood experiences like attachment theory and the presence of an "internal pot of gold."