She was one of the first in the study of racism to argue that the notion of "race" has no scientific value, does not refer to any natural reality and is an arbitrary mode of classification.
[5] In it, Guillaumin analyzes racism as a social fact, and develops the concept of racization as mentioned in previous studies.
[6] According to Naudier and Soriano, this book (her only work, but which also represents the heart of her thinking) should have marked the history of the emergence of studies on the social relations of race in France, but this turning point did not take place.
In 1978, she published Pratique du pouvoir et idée de nature (in two parts), which theorized the appropriation of women through material social relations and naturalist ideology.
[4] In this field, Guillaumin wrote several texts for the Mouvement contre le racisme et pour l'amitié entre les peuples (MRAP) and was involved in feminist groups following on from the May 1968 civil unrest.
[7] The term "sexage" that she created was taken up by Michèle Causse, Danielle Juteau and Nicole Laurin, as well as by Jules Falquet.
A few years after studying at the Sorbonne, she met Nicole-Claude Mathieu and Noelle Bisseret and contributed with them to the collective work entitled: La femme dans sa société.
[7] In a socio-political context where the analysis of the relations of exploitation is mainly based on Marxist theory, Guillaumin shows that the idea according to which "labor power is the ultimate thing one has to live on is inadequate for the entire class of women.
"[7] For example, in marriage, the private form of the appropriation relation, there are no limitations on the wife's employment in terms of time, tasks, number of children to be delivered, etc.
The same is true of domestic work, which women still do overwhelmingly, and which cannot be measured: there is no "punch-in" or "punch-out", but rather a diversity of tasks that can arise at any moment and which require permanent availability.