Current Scientific Views of Psychopathy.

The elegantly written monograph that follows first summarizes historical views of the concept of psychopathy and gives an authoritative review of the current scientific literature having to do with the nature and causes of psychopathy—dating especially from Cleckley's conceptualization. Second, it critically evaluates current policy and practice concerning the application of the psychopathy construct in forensic contexts. These topics are not independent, as the conclusions from the first topic have major implications for the second. To appreciate the importance of the first part, it is helpful to contrast two radically different views. In the " old " or traditional view, psychopathy is seen as a unitary construct that is discrete and qualitatively different from nonpsychopathy. One either is or is not a psychopath. This kind of model works best with a single-gene etiology (causal development) without too much influence from the environment. One either has the genetic vulnerability or does not—as is the case with the single dominant gene for Huntington's chorea or the homozygous recessive genotype for phenylketonuria. In contrast, contemporary approaches to developmental psychopathology focus on individual differences in (often multiple) normal temperaments as risk factors that interact in complex ways with social (and possibly physical) environments. Usually a given risk factor can have multiple adult manifestations or outcomes (phenotypes)—a phenomenon known as multifinality. Similarly , different childhood risk factors often result in somewhat similar adult phenotypes—called equifinality. The developmental literature strongly supports this model. To illustrate this model applied to psychopathy, I will describe what the monograph implies are the most likely risk factors for the two factors and place them in the context of developmental models. We are not certain about the details of these models, and they are undoubtedly simpler than reality, but they illustrate the nature of theorizing about psychopathy, which is the major point. The Psychopathy Checklist-Revised (PCL-R) has dominated research on psychopathy. Factor analyses revealed two factors with a correlation of about 0.5. Factor 1 seems to capture Cleckley's concept of psychopathy much better than Factor 2 (although as the following monograph shows, the PCL-R fails to include some of the positive adjustment features in Cleckleyan psychopathy). A large amount of research now suggests that the etiological contributors to the two factors are different—a conclusion with dramatic implications. The unique features of Factor 1 capture the unemotional-predator concept of psychopathy, widely thought to reflect a low-fear temperament as a core risk factor …