In France, research in history and political philosophy has produced a body of knowledge describing the values and principles that are at the heart of the « republican model of integration ». However, this work has been theoretical and conceptual in nature such that we have in fact very little knowledge about the psychological aspects of the republican model. This thesis is organized in three chapters that present in total seven distinct empirical studies It addressed two major questions: 1) What factors explain the strong support that is observed in France for the principle of republican equality and laïcité? and 2) what are the consequences of this support for prejudice and intergroup relations? In chapter one, the research confirms this strong endorsement of the republican principles among teachers in high schools (Study 1, N = 82) or among university students in widely different fields of study such as psychology (N = 72) or law (N = 234, Study 2). Using a measure of attachment to laïcité that is distinct from a measure of support for principles that are theoretically linked with laïcité, Study 2 showed, for the first time to our knowledge, the distinction between two types of laïcité: an historic laïcité based on freedom of conscience and equality of respects for all beliefs and a new laïcité that emphasizes the need for keep religion private and to ban conspicuous religious signs from public places. In chapter two, three studies examined the psychological motives underlying attachment to the republican principles. As expected, it was shown first, among a representative sample of the French population (N = 1001), that support for republican equality and new laïcité are two variables that explain variance in antiimmigrant prejudice over and above factors that are usually considered in sociology or social psychology. Moreover, whereas egalitarian individuals are usually more supportive of these principles compared to inegalitarians, the results also showed that people who wish to maintain group-based inequality and the social hierarchy becomes strong supporters of laïcité when they perceive an intergroup threat of a symbolic nature (Study 1, chapter two), when they are in a situation of intergroup threat (Study 2, chapter two), or when an intergroup threat of a symbolic type is experimentally induced (Study 3, chapter 2). These results confirm the hypothesis that laïcité is a malleable ideology that can be used as a socially accepted mean of defending a socially undesirable agenda. The third and last chapter of the thesis examined the role of the school in the process of cultural transmission. Study 1 of chapter three (N = 300 pupils) and Study 2 of chapter three (N = more than 1000 pupils) supported a theoretical model proposing that public schools in France lead to a stronger support for republican principles and that this process of cultural transmission mediates the effects of schooling on anti-immigrant prejudice. A decline in the impact of republican equality and a corresponding increase in the impact of new laïcité was however observed. The discussion outlines the theoretical and pedagogical implications of these results.