1. IntroductionSince the 1960s, family forms in most European countries have become more varied, in parallel with increasingly diverse and individualized family life courses. The sequence of demographic events and the pace at which they occur are now less standardized than before (Bruckner and Mayer 2005; Buchmann and Kriesi 2011). Postponed union formation, declines in marriage, and increases in cohabitation represent some of the main changes in family behavior. This process of destandardization and de-institutionalization of family forms is the result of increasing individualization and a weakening of the normative constraints that shape transitions and their sequencing over the life course (Lesthaeghe and Surkyn 2004). These changes in family models have also arisen due to the changing gender system and the increasing economic independence of women and their changing roles in society (Oppenheim, Mason, and Jensen 1995). Growing economic insecurity and changes in job standards have also been major causes of the transformation of the life course (Blossfeld et al. 2005).The question arises of whether such changes have also taken place among immigrants and their descendants, who comprise a large share of the European population. This question is important since, compared to the native-born French, differences and similarities in age at partnership formation and type of union indicate the level of adherence to norms and practices in the host society (Adsera and Ferrer 2014). The postponement of partnership formation and the rise of cohabitation are indicators that individual behaviors are less determined by tradition and more open to individual choice (Bernardt et al. 2007). They also reflect changes in women's roles (Sassler 1997). Thus, union formation patterns indicate the extent to which immigrants and their offspring integrate culturally into their host society (Algan et al. 2012). However, little attention has been paid to the timing of union formation among immigrants, and even less to the type of union they engage in (Kulu and Gonzales-Ferrer 2014).This paper analyzes the integration dynamics across generations of immigrants in France by focusing on partnership formation patterns. France has a long history of immigration, and individuals with an immigrant background represent 20.6% of the 2008 adult population (Insee 2012). They come from an extremely wide range of geographical origins. In some of these regions, unions are formed in a very similar way to the prevailing French model, i.e., widespread cohabitation, rising age at which first-time couples are formed, and frequent separations (Sobotka and Toulemon 2008). In other sending countries, marriage is almost universal, and the age at first marriage remains low. France has also adopted a specific model of integration, i.e., assimilation, by promoting the conformity of immigrants and their descendants to the ideals of the French Republic (Favell 2001). Relatively few cultural rights are granted to immigrants (Koopmans 2010), which limits the persistence of cultural differences (Huschek, Liefbroer, and de Valk 2010). This specific context should theoretically drive a convergence of partnership dynamics towards French standards.In order to analyze this potential convergence in the absence of data that follows immigrant groups over time and over several generations, we compare the partnership dynamics of first- and second-generation immigrants from the same region of origin with those of the native-born. We analyze several outcomes: i) the timing of union formation, ii) the type of first union (cohabitation vs. marriage), and iii) the transition from cohabitation to marriage. We consider decreasing differences between generations of immigrants and the native-born to be a sign of gradual adaptation to the behaviors and norms that prevail in France. Migration patterns differ greatly between men and women, and gender roles are constructed differently in origin and destination societies. …