In this paper we propose explanatory hypotheses about the sexual politics that were from time to time implemented in the configuration of the Pampa del Tamarugal formative community, with the aim to contribute to the archaeological study of social reproduction. The bioanthropological collections of the Tarapacá 40 Cemetery underwent an osteological survey, designed to identify their sexual and age structure. A significant number of contextual references were recovered, and an exploratory analysis of the variation in the sex-age structure of some cemeteries in the region was carried out. The results show a cemetery with all age ranges and a 1:1 sex ratio. On a regional scale, a dichotomous distribution was observed between archaic and formative cemeteries, based on the ratio between adult women and non-adults. We propose that social relations of reproduction and sexual division of labor between the late archaic and the formative society underwent radical transformations, the most direct impact of which could be the social control of female sexuality through the establishment of a kinship-based socio-political regime.