This thesis examines the way working class children’s practices and representations of science areconstructed. It aims to renew the approach of persistent inequalities in access to science pathwaysand careers, in which women and people from the working class and/or ethno-racial minoritiesremain largely underrepresented. In order to question power relationships underlying access toscience in a new way, this research considers science not only as a body of knowledge and aprofessional eld, but also as a culture. Evidence for this study comes from longitudinal interviewsconducted with about 50 children (two interviews, in the 4th and 6th grade) and with parents,teachers, and science mediators. The analysis also relies on the detailed ethnographic study (4years of observation in classrooms) of an educational project aimed at promoting equality inscience which involved part of our sample, thus questioning the effects of this type of program.The thesis establishes that the social construct of gendered, classed and racialised patterns ofattitudes to science is the result of science-related cultural practices developed during childhood.On the one hand, several instances of cultural socialization (family, siblings, peers, school)combine to favor or hinder the development of children’s science hobbies. On the other hand, thescientific culture that children from the working class consume and practice leads them to constructrepresentations of science as other, and devoid of identificatory possibilities. This discourages girlsand boys from formulating science aspirations.