Building upon the work of Thomas Gieryn and Erving Goffman, this paper will explore how the concepts of stigma and boundary work can be usefully applied to history of population science. Having been closely aligned to eugenics in the early 20th century, from the 1930s both demographers and geneticists began to establish a boundary between their own disciplines and eugenic ideology. The eugenics movement responded to this process of stigmatization. Through strategies defined by Goffman as 'disclosure' and 'concealment', stigma was managed, and a limited space for eugenics was retained in science and policy. Yet by the 1960s, a revitalized eugenics movement was bringing leading social and biological scientists together through the study of the genetic demography of characteristics such as intelligence. The success of this programme of 'stigma transformation' resulted from its ability to allow geneticists and demographers to conceive of eugenic improvement in ways that seemed consistent with the ideals of individuality, diversity and liberty. In doing so, it provided them with an alternative, and a challenge, to more radical and controversial programmes to realize an optimal genotype and population. The processes of stigma attribution and management are, however, ongoing, and since the rise of the nature-nurture controversy in the 1970s, the use of eugenics as a 'stigma symbol' has prevailed.