Abstract
By briefly tracing the history of the racialization of the Rwandan identity categories of Hutu and Tutsi whose political manipulations marked Rwanda throughout the 20th century, this article shows the impact of racial ideology on the personal representations of Rwandans. This is what José Kagabo called "the triumph of the idea": a latent imagination integrating biological data into a base of sometimes mutually negative representations between communities and on which the 1994 genocide of the Tutsi is partly inscribed. identity relationship through which the implacable dividing line between executioners and victims would be drawn.