Integrating Advances in Personality Science to Re-Examine the Trait Theory of Voice Disorders

Purpose: Voice disorders associated with vocal hyperfunction are some of the most common vocal pathologies. Certain personality traits are thought to be a risk factor for developing these disorders. The Trait Theory of Voice Disorders (TTVD) provided a unified framework to understand these relationships. This study re-examines the TTVD by adopting current theories and methods from personality science. Method: This cross-sectional study recruited individuals diagnosed with primary muscle tension dysphonia (MTD) or a diagnosis associated with phonotraumatic vocal hyperfunction (PVH), i.e., benign bilateral lesions of the lamina propria and bilateral or unilateral vocal fold polyp(s). Participants completed a contemporary personality battery. Data were analyzed via structural equation modeling and compared to vocally healthy controls.Results: Several significant differences existed between vocally healthy controls (n = 415) and participants with MTD (n = 71) or PVH (n = 38). Compared to the controls, participants with MTD reported lower levels of Stability, Plasticity, Conscientiousness, Openness/Intellect and the corresponding aspects of Industriousness and Intellect, respectively. Conversely, the MTD cohort was significantly higher in Neuroticism and its two corresponding aspects, Withdrawal and Volatility. Likewise, when compared to controls, the PVH reported significantly lower levels of Stability, Agreeableness, its aspect Politeness, and the aspect of Industriousness. Finally, compared to the MTD cohort, individuals with PVH were higher on Extraversion, specifically the aspect of Assertiveness, and lower on the aspect of Politeness. Conclusions: The current study largely replicates the initial TTVD studies updates them with a modern theory of personality. These results provide a strong foundation for future investigations to continue to study the relationships between personality traits and voice disorders.