In addition to these most well-known types, there have been criminologists who have put forward additional constructs. They are only mentioned here because of their relevance to serial criminals, and the interesting similarity in the way they compare to the FBI's "disorganized - organized" typology.

The patterns of episodic aggressive behavior scale is derived from Joel Norris (1990) Serial Killers, London: Arrow Books and also reproduced in Brian Lane & Wilfred Gregg (1992) The Encyclopedia of Serial Killers, NY: Berkeley Books. This particular sociopathic checklist is found in numerous places but extensively featured in both of Samenow's works in the 1970s on criminal personality (thinking errors).

The diagnosis of APD has long been controversial. The criteria for it seem to change with each and every new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-I 1968; DSM-II 1976; DSM-III 1980; DSM-III-R 1987; DSM-IV 1994). The diagnosis was substantially changed with DSM-III when the APA decided to distinguish between child and adult characteristics, and essentially substituted behavioral criteria (like truancy or law violations) for personality criteria (like callousness and selfishness). In the DSM-III-R (R for Revised), the focus was on violence and a list of violent acts (fighting, cruelty to others, cruelty to animals). The current DSM-IV approach essentially says that anything which is not sociopathy, psychopathy or dyssocial personality disorder is antisocial personality disorder, but there is considerable overlap. The diagnostic possibilities are endless; there are at least 3 million possible variations of symptoms on at least 62 different measurable items.

Ongoing research is quite prolific into the factor or principal components analysis of APD characteristics. Most forensic experts believe there are 3-4 factors (groupings of symptoms). One factor involves symptoms that cluster around what might be called a Lack of Planning (promiscuous, irresponsible, impulsive traits and behavior). Another factor clusters around the notion of Disregard for Others. A third factor is clearly related to Adult Criminality. A fourth factor is clearly related to Juvenile Delinquency. Impulsivity appears to be a prototypical (core) feature, but it can take many forms. Definitions of impulsivity are numerous -- a tendency to act without reflection; dysfunctional information processing; a tendency for risk taking; sensation seeking; and an inability to sustain attention. Rating scales are easily available to measure these.

The incidence of APD is twice as high for inner-city residents than in small towns or rural areas, and five times higher in males than in females. It affects people in all social classes, but if someone with APD is born into a family of wealth and privilege, they will usually manage to eek out a successful business or political career. Poorer people with APD tend to wind up in state prison systems. Since African-Americans are seven times more likely to be represented in state prison systems, it's tempting to speculate the incidence of APD among African-Americans is high. However, there are most likely other causes of crime among African-Americans (like unemployment and racism). The fact is that most of the current prison population, white or black, shares the APD diagnosis. All it takes is a juvenile record, an adult offense career, aggressivity, impulsivity, a checkered work history, and/or lack of demonstrable repentance. These can be easily found in almost any prison inmate's dossier.

One of the things closely related to APD is the comorbidity of alcoholism and narcotic addiction. Some of the criteria for a substance abuse disorder are very similar: theft, hazardous behavior, failure to fulfill role functions in home, school, and work. A strong correlation exists between substance abuse and factor 2 (antisocial behaviors) of the psychopathy construct. APDs with a drug addiction have some serious substance abuse problems -- the kind that lead to death by overdose or accident within five years. Are APD and narcotic addiction part of the same disorder, does one lead to the other, or are they are spuriously linked together? From what little research there is, it appears that most of the time, APD precedes narcotic addiction, although some of the time, addiction leads to APD behaviors. People with such comorbid characteristics also usually have undiagnosed other Axis I and Axis II disorders.

From the wild Irish slums of the 19th Century Eastern seaboard to the riot-torn anomic neighborhoods of Los Angeles, our society has always produced sociopaths who are quite often the products of illegitimacy, broken homes, and a lack of any bonding with male or societal authority. Some 70% of sociopaths come from fatherless homes.  Father absence produces many consequences similar to the symptoms of sociopathy -- early, precocious sexuality; antagonistic, deprecating attitude toward the opposite sex; lack of interest in bonding with a durable, stable mate; aggressive acting-out; excessive boasting; and risk-taking behavior. Some 30% of children today are born out-of-wedlock, and another 30% live in divorced homes. These conditions - a problem of unsocialization - produce sociopathy. Furthermore, sociopaths tend to reproduce themselves, that is, they produce more than own their share of illegitimate offspring themselves.

So what is a sociopath? You won't find criteria in the DSM IV or official psychiatric nomenclature, but the construct refers to the largest subgroup of APDs. Most are males, but an increasing number are female. They have otherwise normal temperaments (as opposed to psychopaths who have abnormal temperaments). Some are aggressive, fearless sensation seekers, and others are Machiavellian manipulators. A Machiavellian is a personality type who is a cross between an antisocial personality and a narcissist, and someone who also has an extremely high sense of entitlement. The one thing that all sociopaths have in common is that they are "too much" to handle for their parents or anyone else.  It's common to refer to them as unsocialized, but the dyssocial sociopath does socialize to the mores and values of a dyssocial outgroup, like a gang. Let's explore the four (4) subtypes of sociopaths:

COMMON SOCIOPATHS are the largest subtype and have a weak or unelaborated conscience. They are not ashamed by the same things as you or I would be ashamed of. They are like feral children grown up, taking pleasures and gratifying impulses at every opportunity or temptation. They especially enjoy and take pride in bending or breaking the rules. As teenagers, they are often runaways. As adults, they are often geographically mobile, living in shelters, or taking advantage of welfare systems. They are experienced shoplifters. They have quite active sex lives. They are usually of average intelligence, but don't do well in school and never seem to break out of low-paying dead-end jobs. Nevertheless, they seem genuinely happy with their lives, unburdened by any sense of negative self-worth or the fact that they have not been a functional, contributing member of society.

ALIENATED SOCIOPATHS have never developed the ability to love, empathize, or affiliate in real life with another person. They will show more emotion toward their pet or a personal artifact than toward a person. Or, they may hate animals and live out their emotional life by watching TV (identification with soap opera characters is a common pattern). Dating and marriage relationships will be very barren and empty. They won't get along with the neighbors. They live in a shell. They have a cold, callous attitude toward human suffering or any social problem in the society they live in. They just don't care because it's outside their range of empathy. Most will believe they are justified in this because they feel they were cheated in some way themselves by society, and a few will be more than happy to rant and rave about it to anyone who listens. They are chronic complainers, and underneath it all, they would like to see nothing better than all of society destroyed.

AGGRESSIVE SOCIOPATHS derive strong, yet nonperverse gratification from harming others. They like to hurt, frighten, tyrannize, bully, and manipulate. They do it for a sense of power and control, and will often only drop subtle hints about what they are up to. They polish their aggressive, domineering manner in such a way to disguise any intimidation others might feel. They seek out positions of power, such as parent, teacher, bureaucrat, supervisor, or police officer. Their style is one of passive aggression as they systematically go about sabotaging the ideas of others to get their ideas in place. In their spare time, they like to hunt or occasionally do sadistic things like find stray dogs and cut them up. They are usually effective at getting their way, and are especially vindictive if resisted or crossed. They don't follow the social norm of reciprocity like others do.

DYSSOCIAL SOCIOPATHS identify and hold an allegiance with a dyssocial, outcast, or predatory subculture. Any subculture will do, as long as it runs counter to established authority. They are capable of intense loyalty, and even a feeling of guilt and shame, within such limited circles. They seem to continually fall upon bad luck and bad companions, however. While they will constantly complain that none of this is their fault, behind it all is a kind of self-defeating mechanism in the poor choices they made themselves.

Psychopaths cannot be understood in terms of antisocial rearing or development. They are simply morally depraved individuals who represent the "monsters" in our society. They are unstoppable and untreatable predators whose violence is planned, purposeful and emotionless. The violence continues until it reaches a plateau at age 50 or so, then tapers off. Their emotionlessness reflects a detached, fearless, and possibly dissociated state, revealing a lower autonomic nervous system and lack of anxiety. It's difficult to say what motivates them - control and dominance possibly - since their life history will usually show no bonds with others nor much rhyme to their reason (other than the planning of violence). They tend to operate with a grandiose demeanor, an attitude of entitlement, an insatiable appetite, and a tendency toward sadism. Fearlessness is probably the prototypical (core) characteristic (the low-fear hypothesis). It's helpful to think of them as high-speed vehicles with ineffective brakes. Certain organic (brain) disorders and hormonal imbalances mimic the state of mind of a psychopath.

There are four (4) different subtypes of psychopaths. The oldest distinction was made by Cleckley back in 1941 between primary and secondary. However, we'll explore the other two subtypes first:

DISTEMPERED PSYCHOPATHS are the kind that seem to fly into a rage or frenzy more easily and more often than other subtypes. Their frenzy will resemble an epileptic fit. They are also usually men with incredibly strong sex drives, capable of astonishing feats of sexual energy, and seemingly obsessed by sexual urges during a large part of their waking lives. Powerful cravings also seem to characterize them, as in drug addiction, kleptomania, pedophilia, any illicit or illegal indulgence. They like the endorphin "high" or "rush" off of excitement and risk-taking. The serial-rapist-murderer known as the Boston Strangler was such a psychopath.

CHARISMATIC PSYCHOPATHS are charming, attractive liars. They are usually gifted at some talent or another, and they use it to their advantage in manipulating others. They are usually fast-talkers, and possess an almost demonic ability to persuade others out of everything they own, even their lives. Leaders of religious sects or cults, for example, might be psychopaths if they lead their followers to their deaths. This subtype often comes to believe in their own fictions. They are irresistible.

PRIMARY PSYCHOPATHS do not respond to punishment, apprehension, stress, or disapproval. They seem to be able to inhibit their antisocial impulses most of the time, not because of conscience, but because it suits their purpose at the time. Words do not seem to have the same meaning for them as they do for us. In fact, it's unclear if they even grasp the meaning of their own words, a condition that Cleckley called "semantic aphasia." They don't follow any life plan, and it seems as if they are incapable of experiencing any genuine emotion.

SECONDARY PSYCHOPATHS are risk-takers, but are also more likely to be stress-reactive, worriers, and guilt-prone. They expose themselves to more stress than the average person, but they are as vulnerable to stress as the average person. They are daring, adventurous, unconventional people who began playing by their own rules early in life. They are strongly driven by a desire to escape or avoid pain, but are unable to resist temptation. As their anxiety increases toward some forbidden object, so does their attraction to it. They live their lives by the lure of temptation.

Hare's PCL-R 20-item checklist is based on Cleckley's 16-item checklist, and
the following is a discussion of the concepts in the PCL-R:

INTERNET RESOURCES
The Antisocial Personality Disorder Homepage
Can Criminal Psychopaths be Identified?
Dr. Hare's Psychopathy/Antisocial Personality Confusion article
Dr. Stanton Samenow's Home Page
The Internet Danger Zone: Psychopaths or Sociopaths