by Malek Mneimne, M.A.
For the past several decades, mental health clinicians and researchers have debated over the classification and diagnosis of personality disorders. This debate has centered on the issue of conceptualizing personality disorders as separate, categorical entities or as combinations of extreme degrees of personality traits that everyone has to some degree (e.g., extroversion-introversion, neuroticism). Supporters of the dimensional view of personality disorders argue that a dimensional view is more consistent with empirical evidence, retains more information about the client, and is more useful to clinicians, whereas a categorical view is somewhat arbitrary; either the client has the personality disorder or does not, which ignores potentially useful information. The current edition of the Diagnostic and Statistical Manual for Mental Disorders views personality disorders categorically; largely as a result of this debate, the next edition will include personality dimensions.
Most concepts and stimuli in the world can be viewed either categorically or dimensionally. For instance, we usually consider a person’s race to be categorical (i.e., Caucasian, Black, Hispanic, Asian, etc). But race can also be viewed dimensionally. We could determine how “Caucasian” or “Black” somebody is by measuring percentages of different races in their familial lineage—e.g., 90% Caucasian, 10% Black or 75% Black, 10% Hispanic, 10% Caucasian, 5% Asian. Moreover, although we often view people as either “male” or “female,” sex can be viewed dimensionally as well, by measuring levels of sex hormones. Academic letter grades are categorical; the actual number grade is dimensional. Similarly, we often rate our own and others’ performances in specific situations as “good, bad, or ugly,” instead of reporting performance statistics (e.g., number of touch-downs, three-pointers, or strike-outs, batting average, on-base percentage, etc).
These kinds of “black-and-white” and “all-or-nothing” perceptions simplify the complex world and make it easier to comprehend and communicate what’s going on around us, but they do so at a cost. In statistics, categorizing people into groups on the basis of their scores on a continuous measure reduces power to detect significant findings. In psychology, we know that such perceptions have the potential for overgeneralization, and therefore prejudice, and are a risk factor for depression. When depressed, we usually think of ourselves, the world, and our future categorically—as always being a crap, a failure, or worthless. Such statements neglect to consider other potential characteristics of ourselves, the world, and future. For someone to be a “crap,” “failure,” or “worthless,” they would have to be a crap, failure, or worthless 100% of the time, which is highly unlikely, if not impossible. Therefore, such perceptions are referred to as “thinking errors.” Errors in top-down processing. Factually inaccurate distortions of reality. Ignorance is not always bliss.
Viewing concepts and stimuli dimensionally can be more difficult and time-consuming but provide a more complete and comprehensive picture of the world from the bottom-up. According to REBT, one way of adopting a dimensional approach to our understanding of the world is to avoid using absolutes, such as always/never, everybody/nobody, 100%/ 0%. Absolutes imply that no exceptions occur. Whether an exception occurs is a question for which we may not ever know the answer. Nevertheless, if your goal is to appear consistent with reality and feel less depressed (or grandiose), then my advice is to choose a dimensional approach to the interpretation of reality. If you must rate, then rate people in terms of percentages of multiple personality traits; rate performances or behaviors in a situation on multiple dimensions rather than rating the whole self on the basis of one performance or behavior in a situation.