Authenticity is a personality trait, which implies loyalty to one's true self, correspondence to the personality, spatio-temporal life circumstances, and vocation. Three main paradigms of the interpretation of authenticity are compared – person-centered, existential, and agent paradigms. To study the dynamics of everyday experience of authenticity, an exploratory study was conducted on the respondents of three ages: primary school children (7–12 years old, SD_age = 1.12), adolescents (12–17 years old, SD_age = 1.62), and youth (18–23 years old, SD_age =0.92). Each group included 150 people and was balanced by gender. The main method was a research interview followed by a structured tabular thematic analysis. The interview included five thematic blocks covering the main manifestations of authenticity – authentic living, accepting external influence, self-alienation, behavior, and balance of social/individual. The results demonstrate the greater relevance of the existential and agent paradigms for describing the respondents’ authenticity. In all ages, authenticity was described as an initially social feature, stimulated by interaction with other people and manifested in it. The influence of other people was not considered by respondents as a source of self-alienation, regardless of age. The descriptions of authenticity become richer and more differentiated with age. In primary school children, authenticity is reflected weaker, and the state of self-alienation is recognized with difficulty. Finally, manifestations of authenticity are age-specific and closely related to the content of the developmental tasks of each of the considered stages. The results obtained can be used in further research and applied programs.