Variations on the family resemblance hypothesis as applied to personality disorders

Diagnosis and classification of the personality disorders is controversial and problematic. Diagnostic reliability is uneven because of overlapping of traits and the lack of clear boundaries between categories. This study demonstrates that personality disorder diagnosis is dependent on the total number of defining features. Clinicians tend to ignore the presence of conflicting features when making a diagnosis. A new research instrument, artificially created case histories that allow the specific manipulation of defining features (i.e., diagnostic criteria), is described.