Verification Vs. Falsification Bias in Assessing Dissociative Amnesia Claims: The Influence of Specialization and Assessee Gender

In psychological assessment, simply confirming (verifying) an assessee's symptom presentation without inspecting its validity (falsifying) constitutes confirmation bias. Similarly, bias exists if assessors only refute presentations without attempting verification. This risk is pronounced for controversial constructs like dissociative symptoms, where clinical and forensic approaches diverge. We investigated whether psychology trainees' specialization (clinical vs. forensic) and assessee gender (male vs. female) introduce bias in test selection reflecting the tendency to verify or to falsify claims of dissociative amnesia. We conducted two vignette-based studies. Study 1 (N=160) involved undergraduate psychology trainees instructed to simulate a clinical or forensic role. Study 2 (N=134) involved master's trainees enrolled in clinical or forensic degree programs. Participants selected instruments from a list containing verification (symptom inventories) and falsification (validity screening) tools. Both studies revealed a significant bias toward verification, with participants consistently preferring confirmatory measures over validity tests, regardless of the specialization role and assessee's gender. However, there was a significant reduction in the magnitude of verification bias between the studies, suggesting a mitigating effect of advanced training. These findings indicate that a "verification bias" may be inherent in early professional development. Potential implications are discussed.