According to Baron-Cohen, empathy requires not only the capacity to suspend self-interest and a single-minded focus, but also the ability to identify with what another person is thinking or feeling, and to respond with appropriate emotions. In other words, true empathy entails both recognition and response.
Erosion of human empathy, he suggests, can be caused by many factors, such as rage, jealousy, abandonment, revenge, hatred, physical abuse, and even the desire to protect. As such, heinous acts inflicted upon another can occur as a function of either transient moments of “empathy erosion,” or as an enduring, lifelong pattern of behavior.