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Biomedical subjects

Nancy S Kim

Publications and source records attributed to Nancy S Kim.

4 recordsLinked to original sources

From symptoms to causes: diversity effects in diagnostic reasoning.

A single causal agent can often give rise to a cascade of consequences that can be envisioned as a branching pathway in which symptoms are the terminal nodes. In three studies, we investigated whether reasoning about root causes on the basis of such symptoms would conform to a diversity effect analogous to that found in inductive reasoning about properties of hierarchically organized categories. A strong diversity effect was found both for reasoning about medical diseases that drew on existing background knowledge and for reasoning that did not. Specifically, the presence of a root cause was more likely to be induced when the symptoms present were further apart in the branching structure.

Diagnosis, Differential↗

Understanding behavior makes it more normal.

Meehl (1973) has informally observed that clinicians will perceive a patient as being more normal if they can understand the patient's behaviors. In Experiment 1, undergraduate participants received descriptions of 10 people, each with three characteristics (e.g., frequently suffers from insomnia) taken from the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994). When the characteristics formed a plausible causal chain, adding a causal explanation increased perceived normality; but when a causal chain was implausible, perceived normality decreased. In Experiments 2 and 3, a negative life event (e.g., is very stressed out due to her workload) was added as an explanation for the first characteristic in a three-characteristic causal chain. Undergraduates, graduate students in clinical psychology, and expert clinicians all reliably perceived the patients as being more normal with these explanations than without them, confirming Meehl's prediction.

Cognition↗

The influence of naive causal theories on lay concepts of mental illness.

Two experiments, incorporating both real-life (Experiment 1) and artificial (Experiment 2) stimuli, demonstrated that lay concepts of mental disorders can be reliably predicted from subjects' naive causal theories about those disorders. Symptoms that are deeper causes (X, where X causes Y, which causes Z) are more important in lay concepts than intermediate causes (Y), which in turn are more important than terminal effects (Z). In addition, symptoms that cause or are caused by other symptoms are more important in lay concepts than symptoms not participating in any causal relationships. Implications of these results for current models of categorization and for research on lay theories of mental disorders are discussed, and future directions for research are suggested.

Humans↗

Clinical psychologists' theory-based representations of mental disorders predict their diagnostic reasoning and memory.

The theory-based model of categorization posits that concepts are represented as theories, not feature lists. Thus, it is interesting that the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) established atheoretical guidelines for mental disorder diagnosis. Five experiments investigated how clinicians handled an atheoretical nosology. Clinicians' causal theories of disorders and their responses on diagnostic and memory tasks were measured. Participants were more likely to diagnose a hypothetical patient with a disorder if that patient had causally central rather than causally peripheral symptoms according to their theory of the disorder. Their memory for causally central symptoms was also biased. Clinicians are cognitively driven to use theories despite decades of practice with the atheoretical DSM.

Adult↗