Confirmatory bias occurs when a clinician preferentially accepts or seeks evidence that confirms an initial hypothesis at the expense of thorough consideration of emerging contradictory evidence (Garb 2003). For example, a clinician may formulate an initial impression that a client has dementia based on a referral question. During the clinical interview, the clinician may focus on questions relating to memory and change in activities of daily living while failing to ask questions that specifically pertain to differential diagnoses, such as major depressive disorder. In neuropsychological settings, this generally unintentional bias may impair judgment, hamper decision-making, produce false reports, and negatively impact the assessment approach and interpretation of findings. To address this bias, the clinician should systematically review all available data within a hypothesis-testing framework in an effort to remain as impartial as possible (Weiner and Greene 2007).
References and Readings
- Garb, H. N. (2003). Clinical judgment and mechanical prediction. In I. B. Weiner, D. K. Freedheim, M. Gallagher, J. A. Schinka, & R. J. Nelson (Eds.), Handbook of psychology (pp. 27–42). New York: Wiley.Google Scholar
- Weiner, I. B., & Greene, R. L. (2007). Handbook of personality assessment. New York: Wiley.Google Scholar