Impostor syndrome (IS), or persistent feelings of fraudulence despite evidence of success, is associated with poor mental health outcomes. About 70% of people in the United States report experiencing IS at least once, with some populations facing more chronic IS. This study examined the influence of family dynamics on adolescent socialization and adult outcomes, which we hypothesized would relate to IS, comparing populations we suspected to be high in IS (trained meteorologists and professional dancers) to a general-population sample. We hypothesized IS would positively correlate with conditions of worth and controlling and intrusive parenting recalled from adolescence; adult social comparison; and two aspects of adult inauthenticity; and would negatively correlate with adult authenticity, trait mindfulness, and self-compassion, thought to be potential buffers from the effects of IS. Finally, we investigated the predictive ability of conditions of worth with respect to social comparison and inauthenticity. Results largely supported predictions and suggest that IS-associated feelings are a problem for meteorologists, dancers, and members of the general population, and have their roots in child and adolescent development. Practical and theoretical implications are discussed.