<P> The German psychiatrist Koch sought to make the moral insanity concept more scientific, and in 1891 suggested the phrase' psychopathic inferiority', theorized to be a congenital disorder . This referred to continual and rigid patterns of misconduct or dysfunction in the absence of apparent mental retardation or illness, supposedly without a moral judgment . Described as deeply rooted in his Christian faith, his work has been described as a fundamental text on personality disorders that is still of use today . </P> <P> In the early 20th century, another German psychiatrist, Emil Kraepelin, included a chapter on psychopathic inferiority in his influential work on clinical psychiatry for students and physicians . He suggested six types--excitable, unstable, eccentric, liar, swindler and quarrelsome . The categories were essentially defined by the most disordered criminal offenders observed, distinguished between criminals by impulse, professional criminals, and morbid vagabonds who wandered through life . Kraepelin also described three paranoid (meaning then delusional) disorders, resembling later concepts of schizophrenia, delusional disorder and paranoid personality disorder . A diagnostic term for the latter concept would be included in the DSM from 1952, and from 1980 the DSM would also include schizoid, schizotypal; interpretations of earlier (1921) theories of Ernst Kretschmer led to a distinction between these and another type later included in the DSM, avoidant personality disorder . </P> <P> In 1933 Russian psychiatrist Pyotr Borisovich Gannushkin published his book Manifestations of psychopathies: statics, dynamics, systematic aspects, which was one of the first attempts to develop a detailed typology of psychopathies . Regarding maladaptation, ubiquity, and stability as the three main symptoms of behavioral pathology, he distinguished nine clusters of psychopaths: cycloids (including constitutionally depressive, constitutionally excitable, cyclothymics, and emotionally labile), asthenics (including psychasthenics), schizoids (including dreamers), paranoiacs (including fanatics), epileptoids, hysterical personalities (including pathological liars), unstable psychopaths, antisocial psychopaths, and constitutionally stupid . Some elements of Gannushkin's typology were later incorporated into the theory developed by a Russian adolescent psychiatrist, Andrey Yevgenyevich Lichko, who was also interested in psychopathies along with their milder forms, the so - called accentuations of character . </P> <P> In 1939, psychiatrist David Henderson published a theory of' psychopathic states' that contributed to popularly linking the term to anti-social behavior . Hervey M. Cleckley's 1941 text, The Mask of Sanity, based on his personal categorization of similarities he noted in some prisoners, marked the start of the modern clinical conception of psychopathy and its popularist usage . </P>

Which of the following is a type of personality disorder