Essentialism and a Folk-Taxonomic Approach to the Classification of Psychopathology

The topic of psychiatric classification has attracted a recent series of conceptual analyses in which the authors have attempted to explicate the fundamental concepts associated with the classification of psychopathology. Wakefield's discussion of the concept of mental disorder is a well-recognized example (Wakefield 1988, 1992, 1999). But many other authors have added their comments on the meaning of fundamental concepts associated with psychiatric classification (see Blashfield and Livesley 1991; Carson 1991; Follette 1997; Fulford 1989, 1999; Lilienfeld and Marino 1995, 1999; Millon 1991; Reznek 1989; Sadler 1996; Sarbin 1997). Zachar (2000) has joined this chorus of conceptual analyses by attacking the implicit essentialism in contemporary psychiatric classification. Instead, he suggests that the categories in a classification of mental disorders should be viewed as practical kinds, not natural kinds.

A primary strength of Zachar's paper is that he tackles a complicated topic and attempts to add clarity to an important and muddy issue in psychiatric classification. For instance, Zachar is particularly bold in challenging the views of Costa and McRae. These two research psychologists claim that they had uncovered the "essence" of personality through their factor analytic studies because their research has persistently suggested three to five dimensions of personality traits. Zachar also is critical of a genetic approach to psychopathology. Many of the biologically oriented psychiatrists in the field today are ignoring the debate over the nature of psychiatric constructs, since they believe that finding a biological substrate to mental disorders will solve all of the mental-health field's pressing issues. Zachar questions this belief and points out its limitations.

In his conceptual analysis of psychiatric classification, Zachar uses a philosophy of pragmatism in order to comment on psychiatric disorders. Much of Zachar's paper is devoted to debunking the implicit essentialism that most psychiatrists and psychologists associate with categories of psychopathology. Zachar is critical about a simple-minded essentialism that assumes that categories can be defined by necessary and sufficient conditions, that categories refer to sets of patients, and that the meanings of categories can be reduced to biologically based etiologies.

Zachar's attacks on essentialism parallel many of the discussions by the other authors noted in the first paragraph of this commentary. Fulford, Lilienfeld, Reznek, Sarbin, and Wakefield all seem to agree that an essentialist perspective to psychiatric classification will not suffice (but see Wakefield 2000). Values, stories, prototypes, meaning, cultural context, and usefulness are additional concepts that, in some way, must be included in our understanding of mental disorder. Biological reductionism, by itself, will not explain psychopathology.

Our view of the DSM is that it can be viewed as a folk taxonomy. Originally, folk taxonomies were studied by cultural anthropologists who were working with relatively isolated, non-Western cultures. These anthropologists were interested in how non-Western peoples classified living organisms and the extent to which these ethnobiological classifications matched the "scientific" classifications accepted by Western culture. Berlin and other anthropologists have formulated a set of principles that appear across these ethnobiological classifications. This classification structure will be discussed in relation to the DSM.

The DSM as a Folk Taxonomy

The heart of the folk-taxonomic structure is a hierarchical organization of categories. This structure is remarkably similar across cultures. The folk-taxonomic hierarchy is also similar to the structure of the DSM. Both the DSM and folk taxonomies have a hierarchical organization; they both have four to six ranks; and neither the DSM nor folk taxonomies have systems in which the ranks have names. The similarities between folk taxonomies and the DSM will be discussed below for each of the five ranks that are usually found in folk-taxonomic system.

The most general rank is the kingdom rank (Berlin, Breedlove, and Raven 1974). In classifications of living things, the kingdom rank is the rank that contains a general category such as "plant" or "animal" (Atran 1998). In this...