With the rise of globalization, culture mixing increasingly occurs not only between groups and individuals belonging to different cultures but also within individuals. Biculturals, or people who are part of two cultures, are a growing population that has been studied in recent years; yet, there is still much to learn about exactly how their unique experiences of negotiating their cultures affect the way they think and behave. Past research has at times relied on models of biculturalism that conceptualize biculturals’ characteristics and experiences as simply the sum of their cultures’ influences. Yet, the way biculturals negotiate their cultures may result in unique psychological and social products that go beyond the additive contributions of each culture, suggesting the need for a new transformative theory of biculturalism. In this theoretical contribution, our aims are threefold: to (a) establish the need for a transformative theory of biculturalism, (b) discuss how our new transformative theory unifies existing research on biculturals’ lived experiences, and (c) present novel hypotheses linking specific negotiation processes (i.e., hybridizing, integrating, and frame switching) to unique products within the basic psychological domains of self, motivation, and cognition.

Despite the growing prevalence of intercultural romantic relationships—in which partners identify with different racial, national, or religious backgrounds—people in intercultural relationships still face marginalization and disapproval from others. Relationship marginalization sends a message to couples that they do not belong together, and partners may feel that their cultural identity and their relationship are disconnected. Two studies—one study of people in intercultural relationships and one of both members of intercultural couples—showed that when people perceived greater relationship marginalization, they were more likely to separate their couple identity from their cultural identity or believe they had to choose between these identities and they were less likely to integrate these identities. Less integration and more separation between a person’s couple and cultural identities was associated with lower relationship quality for both partners. The findings suggest that marginalization can create challenges for the maintenance and quality of intercultural relationships.

Behaving consistently across situations is fundamental to a person’s authenticity in Western societies. This can pose a problem for biculturals who often frame switch, or adapt their behavior across cultural contexts, as a way of maintaining fit with each of their cultures. In particular, the behavioral inconsistency entailed in frame switching may undermine biculturals’ sense of authenticity, as well as Westerners’ impressions of biculturals’ authenticity. Study 1 had a diverse sample of biculturals (N = 127) living in the United States and Canada describe an episode of frame switching (vs. no switching control vs. neutral control) and report on their state authenticity during the episode. Results showed that biculturals recalled feeling less authentic during an instance of frame switching compared to no switching control and neutral control. Study 2 had mainstream Canadians (White and of American, Canadian, or Western European cultural heritage, N = 97) read a hypothetical vignette, from a third-person perspective, about a bicultural who frame switches (vs. no switching control vs. neutral control) and provide their impressions of the bicultural’s authenticity and multiple other desirable traits. Participants rated the bicultural as less authentic when he frame switched compared to no switching control and neutral control, and rated him as less likeable, trustworthy, and warm (but not competent) as downstream consequences of seeing him as less authentic. These results demonstrate that frame switching can come at a cost to authenticity, both in terms of how biculturals see themselves and are seen by others, at least in Western societies. These findings highlight that the way biculturals negotiate their cultures affects them psychologically and socially. In the context of cultural fit, the active process of establishing and maintaining fit with one’s cultures can have unforeseen consequences.

Intercultural romantic relationships are increasingly common and although the obstacles such couples face are well documented, the factors that facilitate their success are less studied. Although cultural differences may present challenges, they also offer opportunities for self-expansion—personal growth via new perspectives, knowledge, and identities. In three studies using cross-sectional, dyadic, longitudinal, and experimental methods ( NTotal = 896), self-expansion was associated with relationship quality and identity outcomes (i.e., identity integration, cultural self-awareness). Self-expanding through a partner’s culture (i.e., cultural self-expansion) was uniquely related to identity outcomes, beyond self-expanding more generally ( relational self-expansion). Furthermore, actively sharing cultures and discussing their differences were linked to greater cultural and relational self-expansion, which in turn differentially predicted partners’ relationship quality and cultural identities. These studies provide a first look at the role of self-expansion in intercultural relationships, demonstrating that the way couples negotiate their cultures is linked to both relational and personal outcomes.

A growing population of biculturals—who identify with at least two cultures—often frame switch, adapting their behavior to their shifting cultural contexts. We demonstrate that frame switching biculturals are perceived as inauthentic by majority Americans and consequently seen as less likable, trustworthy, warm, and competent compared to biculturals who do not frame switch or a neutral control (Studies 1–3, N = 763). In Study 2, describing the bicultural’s behavior as authentic despite its inconsistency partly alleviated the negative effects of frame switching. In our preregistered Study 3, majority American women were less romantically interested in and less willing to date a bicultural who frame switched in his dating profiles (mediated by inauthenticity). The way biculturals negotiate their cultures can have social costs and create a barrier to intercultural relations.