According to John B. Horn's essay "AN ENDEMIC SOCIAL DISEASE, A MASK OF SANITY, the term Psychopath can be broken down into two basic types of personality disorders or sub-categories of "Psychopath." They are described below:

Antisocial Personality Disorder
APD is generally associated with criminal behavior, and according to research nearly 65-75% of all criminals have APD. The common characteristic of APD is a complete disregard for the rights of others and the rules of society. Persons with APD seldom show anxiety and don't feel guilt.

Symptoms - APD afflicted persons generally have three or more of the following symptoms:
1. Failure to conform to social norms
2. Deceitfulness, manipulativeness
3. Impulsivity, failure to plan ahead
4. Irritability, aggressiveness
5. Reckless disregard for the safety of self or others
6. Consistent irresponsibility
7. Lack of remorse after having hurt, mistreated, or stolen from another person

Sociopathy
A Sociopath is basically a person with something wrong in their conscience. Typically, they are somehow able to completely neutralize any sense of conscience. The people around a sociopath are generally viewed as objects to be used to achieve their goals. Sociopaths only care about their own needs, or wants. The medical field attributes this mental disease to parental failures usually caused by a lack of a father (this mainly describes the "common" type of sociopath).

There are four types of sociopath generally referred to in the medical field:
1. Commons - Characterized mostly by their lack of conscience.
2. Alienated - Characterized by the inability to love or to be loved.
3. Aggressives - Characterized by a consistent sadistic streak.
4. Dyssocials - Characterized by an ability to follow rules, as long as those rules are the wrong rules.

Some common traits of Sociopaths are:
1. Egocentricity
2. Callousness
3. Impulsivity
4. Conscience Defect
5. Exaggerated Sexuality
6. Excessive Boasting
7. Risk Taking
8. Inability To Resist Temptation
9. Antagonistic
10. Deprecating Attitude Toward The Opposite Sex
11. Lack Of Interest In Bonding With A Mate


(References: Joel Norris (1990) Serial Killers; Brian Lane & Wilfred Gregg (1992) The Encyclopedia of Serial Killers; Lykken, D. (1995) The Antisocial Personalities.)