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.