ABSTRACT
Vaccination plays a crucial role in containing the spread of the COVID-19 pandemic. However, a significant fraction of the global population is reluctant to take a coronavirus vaccine. A burgeoning literature has considered mainly adaptive personality traits as antecedents of vaccine hesitancy (i.e., Big Five and HEXACO), while maladaptive personality traits (i.e., "Dark Tetrad" of personality) are often a comparatively neglected area. In this research, we examined the relationship between everyday sadism and intention to get vaccinated against COVID-19. We theorized that driven by antisocial tendencies and social indifference, individuals with higher sadism may be less willing to obtain a vaccine. Employing a bug-killing paradigm to capture everyday sadism, we tested this prediction in a Chinese sample of non-student adults (N = 188). Support for this proposition was found in the lab task, which demonstrates that sadism was associated with more vaccine refusal spanning the self-report and behavioral domains. In addition, we showed that the sadistic behavioral choices can be predicted with self-report measure of sadistic personality. These findings highlight the important role of maladaptive personality traits in predicting vaccination attitudes and intentions.