First a bit of terminological history, to clear up any confusion about the meanings of “sociopath,” “psychopath,” and related terms. In the early 1800s, doctors who worked with mental patients began to notice that some of their patients who appeared outwardly normal had what they termed a “moral depravity” or “moral insanity,” in that they seemed to possess no sense of ethics or of the rights of other people. The term “psychopath” was first applied to these people around 1900. The term was changed to “sociopath” in the 1930s to emphasize the damage they do to society. Currently researchers have returned to using the term “psychopath.” Some of them use that term to refer to a more serious disorder, linked to genetic traits, producing more dangerous individuals, while continuing to use “sociopath” to refer to less dangerous people who are seen more as products of their environment, including their upbringing. Other researchers make a distinction between “primary psychopaths,” who are thought to be genetically caused, and “secondary psychopaths,” seen as more a product of their environments.The current approach to defining sociopathy and the related concepts is to use a list of criteria. The first such list was developed by Hervey Cleckley (1941), who is known as the first person to describe the condition in detail. Anyone fitting enough of these criteria counts as a psychopath or sociopath. There are several such lists in use. The most commonly used is called the Psychopathy Checklist Revised (PCL-R), developed by Robert Hare and his colleagues. An alternative version was developed in 1996 by Lilienfeld and Andrews, called the Psychopathic Personality Inventory (PPI). The book that psychologists and psychiatrists use to categorize and diagnose mental illness, the Diagnostic and Statistical Manual of Mental Disorders, (DSM IV) contains a category for something called “antisocial personality disorder” (APD), while the World HealthOrganization delineates a similar category it calls "dissocial personality disorder." These are much broader categories than that of psychopathy. The category of psychopath is seen as included within this category but considerably smaller so that only roughly 1 in 5 people with APD is a psychopath.Uncaring-The PCL describes psychopaths as being callous and showing a lack of empathy, traits which the PPI describes as “coldheartedness.” The criteria for dissocial personality disorder include a “callous unconcern for the feelings of others.” There are now several lines of evidence that point to the biological grounding for the uncaring nature of the psychopath. For us, caring is a largely emotion-driven enterprise. The brains of psycopaths have been found to have weak connections among the components of the brain’s emotional systems. These disconnects are responsible for the psychopath’s inability to feel emotions deeply. Psychopaths are also not good at detecting fear in the faces of other people (Blair et al., 2004). The emotion of disgust also plays an important role on our ethical sense. We find certain types of unethical actions disgusting, and this work to keep us from engaging in them and makes us express disapproval of them. But psychopaths have extremely high thresholds for disgust, as measured by their reactions when shown disgusting photos of mutilated faces and when exposed to foul odors. One promising new line of research is based on the recent discovery of a brain network responsible for understanding the minds of others. Called the default mode network (because it also performs other tasks and is operating most of the time when we are awake) it involves a cluster of several different areas in the brain’s cortex. The first studies have been done on function of this network in psychopaths and as expected there are problems there. Different studies have noted “aberrant functional connectivity” among the parts of the network, along with reduced volume in some of the networks crucial areas. ShallowÂ
