The phenomenon of whistleblowing has always attracted scientific attention and received quite a definitive interpretation. However, the popular evaluation of whistleblowing remains ambiguous: it ranges from extremely negative to demands to legalize it as a social institution, which makes related studies highly relevant. Law, phenomenology, sociology, and behavioral studies have their own definitions of this phenomenon. As a result, its overall understanding still remains multifaceted, as each science focuses on its own epidemiological and etiological factors and proceeds from its own methodology in assessing the consequences of whistleblowing as negative or positive. The authors analyzed numerous scientific sources and revealed a lack of empirical research about the whistleblower as a personality, e.g. personal dispositions, components, structure, motivations, social consequences, etc. The paper introduces some materials that partially fill this gap. The authors used a specialized projective diagnostic technique (BUK-MIF v.7.2) to study various manifestations of human personality. The first stage of the research involved a handwriting analysis of denunciation samples dated 1826–1988. After that, the results were compared with the data of similar psychographic diagnostics in control groups and groups of respondents with addictive behavior. The authors used data factorization, regression, variance, and graphical data analysis to identify the psychological symptom cluster of a whistleblower as a personality. After defining its stability and differentiating properties, the authors built an empirical model of motivation for the act of whistleblowing and described its intentional, regulatory, cognitive, dispositional, and beneficial components.