The actions of serial killers shock many people and they wonder why serial killers do what they do and what would make one killer more evil than another killer. John Wayne Gacy and Jeffery Dahmer, two of the most infamous serial killers of the 20th century, can be compared through the use of various sociological theories and tools, which can work together, to evaluate the psychopathy of these killers and produce a broadly supported explanation of why they do what they do. Some gimmicks and explanations include Michael Stone's Gradations of Evil, Robert Hare's Psychopathy Checklist, James Fallon's explanation of the cause of evil in his TED Talk "Exploring the Mind of a Murderer," and finally the analysis of evil by Phillip Zimbardos in his "Psychology of Evil" TED Talk, which will be used to understand Gacy and Dahmer by examining their lives and behaviors. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay Two sociological tools that can assess Dahmer and Gacy's psychopathy are Michael Stone's Gradations of Evil and Robert Hare's Psychopathy Checklist. Michael Stone's Evil Rating is used to evaluate how evil a person is by examining criminal behavior. Gacy tortured, raped and killed his victims, Dahmer was a necrophiliac who also tortured, raped and killed his victims but would also cannibalize his victims. Dahmer and Gacy fall into category 17 because they were sexually perverse serial killers, yet they tortured their victims, so they also fall into category 18. In Stones' gradations, categories 17 and 18 fall into the sixth level in the gradations of evil, the third level it is where the psychopathic characteristics begin to manifest themselves. Dahmer and Gacy pass level three by three levels, making them psychopathic, according to Stone's method. Dr. Robert Hare's Revised Psychopathy Checklist can assess the number and extent of psychopathic behavioral and personality traits that Gacy and Dahmer had, which will help show how psychopathic they were and whether or not either of them was more psychopathic of the other. Hare established a scoring system, the range for most ordinary people is less than 20, 20 to 29 is borderline psychopathy, and a score of 30 or more satisfies the reasons for psychopathy (Hare). The traits that Hare exhibits in the personality category of his checklist are ease and superficial charm, a grandiose sense of self-worth, a pathological inability to tell the truth, a need to defraud and manipulate others, a lack of remorse or sense of guilt, superficial affection, insensitivity. and a lack of empathy and inability to accept responsibility for one's actions. In the second factor of his checklist, Hare presents the behavioral characteristics of a psychopath which include a parasitic lifestyle, poor behavioral control, inability to adopt realistic long-term goals, impulsivity, irresponsibility, juvenile delinquency, early behavioral problems, neediness of stimulation or propensity to boredom, revocation of condition of release, short-term or common-law serial marital relationships, and sexual promiscuity (Hare). Testing these killers led to an interesting conclusion, Gacy got a 24, Dahmer on the other hand got a 31. It is baffling that Gacy does not meet all the criteria of a psychopath on Hare's checklist. Gacy scored less than Dahmer because he showed no early behavioral problems, no juvenile delinquency, and had realistic long-term goals..