David Marcus

Dr. David Marcus is a Professor and Director of Clinical Training at Washington State University's Department of Psychology. He specializes in psychopathy, dark personality traits, and psychotherapy research, with a focus on taxometric methods to distinguish categorical vs. dimensional constructs in psychopathology.

• Education: Ph.D. from Clark University (1989)

His research explores the latent structure of psychopathy and related disorders, behavioral correlates of dark traits (e.g., psychopathy-sadism links), and allegiance effects in psychotherapy outcomes. Recent work includes scale development (e.g., Triarchic Psychopathy Scales from HEXACO-100) and network analyses of personality disorders.

The Adult Psychopathology Lab, which he leads, investigates psychopathy in non-forensic settings, health anxiety, and methodological rigor in clinical research. Publications from 2013–2025 span psychopathy taxometrics, dark triad traits (sadism, Machiavellianism), and psychotherapy meta-analyses.