Introduction
Cross-racial/ethnic friendships represent a form of positive intergroup interactions that have been shown to reduce prejudice (Chavez et al.,
2021) and support students’ positive school adjustment, particularly for immigrant students (Schachner et al.,
2018). These interactions are especially critical in today’s school contexts, as U.S. public schools serve an increasingly diverse student population, with over half of students identifying as racially and ethnically minoritized (National Center for Education Statistics,
2024) and a growing number coming from immigrant backgrounds (Center for Immigration Studies,
2023). Promoting cross-racial/ethnic friendships, however, requires intentional efforts because adolescents, particularly those from immigrant families, show a persistent preference for making friends with same-racial/ethnic peers (Joyner & Kao,
2000; Titzmann & Silbereisen,
2009). Despite the importance of cross-racial/ethnic friendships, several research gaps remain. Evidence regarding the impact of school diversity on cross-racial/ethnic friendships is conflicting, with studies documenting both positive and negative effects (Fischer,
2008; Kogachi & Graham,
2021) and largely overlooking the potential for non-linear relations. Moreover, little is known regarding how malleable contextual factors, such as perceived school climate, facilitate cross-racial/ethnic friendships and how such influences may differ based on adolescents’ social positions, such as immigrant status (Titzmann,
2014). To address these gaps, the current study has two purposes. First, this study examines whether and how school diversity relates to friendship diversity and whether the association between school diversity and cross-racial/ethnic friendships varies across adolescents from immigrant versus non-immigrant families. The second purpose is to evaluate the role of school interracial climate in cross-racial/ethnic friendships and examine if this relation likewise depends on adolescents’ immigrant status. These associations were analyzed within a multilevel framework to distinguish the effects on cross-racial/ethnic friendships at the school and student levels using a sample of U.S adolescents.
Cross-Racial/Ethnic Friendships
Cross-racial/ethnic friendships yield significant benefits for adolescents and society. For adolescents, being friends with individuals from different racial and ethnic backgrounds has been linked to reduced relational victimization (Kawabata & Crick,
2011) and enhanced perceived school safety (Chen & Graham,
2017). Among students with culturally marginalized identities, cross-racial/ethnic friendships have been associated with more positive socioemotional development (Kelleghan et al.,
2019; Liu et al.,
2020) and less perceived vulnerability in schools (Graham et al.,
2014). Moreover, the positive effects of cross-racial/ethnic friendships extend beyond individual well-being. Documented linkages of cross-racial/ethnic friendships with more favorable intergroup attitudes (Chen & Graham,
2017; Kelleghan et al.,
2019), greater inclusivity (Kawabata & Crick,
2008), and reduced prejudice (Ahmad et al.,
2018) highlight the crucial role that cross-racial/ethnic friendships play in fostering social cohesion.
Despite the extensive benefits of cross-racial/ethnic friendships, adolescents have been consistently observed to gravitate toward making friends who share their same-race/ethnicity (Kogachi & Graham,
2021), meaning that intentional strategies may be necessary to encourage and thus reap the benefits of cross-racial/ethnic friendships. Several theoretical rationales, including person-context fit theory and similarity, have indicated that individuals tend to form friendships with others sharing more similarities with them (Magnusson & Stattin,
1996; Urberg et al.,
1998). Given the advantages of cross-racial/ethnic friendships for adolescents and their potential for enhancing long-term social harmony and inclusion, further research into strategies promoting cross-racial/ethnic friendships in schools is needed.
The Role of School Diversity
Several theories point to the significant role of school racial and ethnic composition in cross-racial/ethnic friendships formation but differ in the expected impacts. One line of theory and research suggests that diverse contexts promote cross-racial/ethnic friendships. Social contact theory asserts that a diverse context provides opportunities for intergroup contact, with positive contact more likely to occur when there is power balance across groups (Pettigrew et al.,
2011). One critical factor shaping perceived power dynamics across groups is numerical representation (i.e., the proportion of a racial and ethnic group within a context); equal group distributions often equate to a more balanced power structure (Pettigrew et al.,
2011). Therefore, schools with more equally distributed racial and ethnic groups (i.e., higher school diversity) likely maximize the opportunities for individuals to make friendships with peers from more racially and ethnically diverse backgrounds. Some studies have observed a positive relation between school diversity and cross-racial/ethnic friendships. For instance, higher school diversity was associated with increased friendship diversity among White and non-White university students (Fischer,
2008), and a recent study of U.S. high school students also observed that students attending more diverse schools developed and maintained higher cross-racial/ethnic friendships over time (Lorenzo et al.,
2024). A study of non-immigrant Swedish youth similarly found that students in classrooms with more immigrant adolescents had a higher proportion of close friends from immigrant backgrounds than those in classrooms with a low proportion of immigrant adolescents (Bohman & Miklikowska,
2021).
In contrast, other theories and empirical studies suggest that diverse contexts can inhibit the development of cross-racial/ethnic friendships. Intergroup conflict and constrict theories propose that students are less likely to form cross-racial/ethnic friendships in schools with higher racial and ethnic diversity (Blalock,
1967; Putnam,
2007). Based on constrict theory, ethnic diversity would hamper social cohesion because people tend to “hunker down” in a diverse context due to less perceived trust (Putnam,
2007). Likewise, conflict theory proposes people perceive increased intergroup threats and favorable in-group bias in more diverse contexts (Blalock,
1967). Some prior studies across settings have corroborated these theoretical propositions. For example, recent research involving middle school students in the Netherlands and the U.S. observed that higher classroom and school diversity were associated with fewer cross-racial/ethnic friendships (Kogachi & Graham,
2021; Munniksma et al.,
2017). Beyond these mixed results, research on the impact of school diversity on cross-racial/ethnic friendships during adolescence compared to other developmental stages is much needed because adolescence is a critical developmental stage for forming intergroup attitudes and self-concepts (Newman & Newman,
2020; Umaña-Taylor,
2016) and notions of social justice (Karcher & Fischer,
2004). Studying how cross-racial/ethnic friendships are formed during adolescence can provide insights into their benefits for adolescent development and fostering positive intergroup interactions during this critical developmental stage to promote long-term positive individual and societal outcomes (Rastogi & Juvonen,
2019).
Most research has primarily tested the linear relation between school diversity and cross-racial/ethnic friendships, overlooking the potential non-linear effects. Policymakers and researchers have grappled with the idea of “sufficient diversity,” assuming that the desirable outcomes of diversity can be achieved when a certain level of representation balance across racial and ethnic groups is maintained (Malcom & Malcom-Piqueux,
2013). Thus, the definition of “meaningful representation” has crucial applications in school desegregation efforts (Danbold & Unzueta,
2020; Garces & Jayakumar,
2014). Research on other areas, such as the association between school racial and ethnic diversity and students’ trust, has observed a U-shaped curvilinear effect (Choi & Lee,
2021). Such observations suggest a need to explore the non-linear effects of school diversity on cross-racial/ethnic friendships to better determine the degree of diversity required in school settings to foster cross-racial/ethnic friendships. This study employs the concept of friendship diversity, referring to having a balanced and diverse group of close friends from different racial and ethnic backgrounds, rather than simply measuring the proportion of cross-racial/ethnic friends (Hooijsma & Juvonen,
2021; Munniksma et al.,
2017). The latter approach could equate adolescents with all friends from a single racial and ethnic background to those with friends from diverse backgrounds, failing to capture meaningful distinctions. For example, if White Student A has two Asian and two Hispanic friends, while White Student B has four Hispanic friends, White Student A would have greater friendship diversity according to the friendship diversity concept. However, both students would have the same proportion of cross-racial/ethnic friends. Thus, assessing friendship diversity can evaluate the benefits of school diversity on cross-racial/ethnic friendships proposed by contact theory.
The Role of Interracial Climate
Apart from understanding how a structural characteristic (i.e., school diversity) may relate to cross-racial/ethnic friendships, interracial climate—defined as practices that promote racial and ethnic group status equality and positive interracial interactions—can serve as another significant contextual predictor of friendship diversity (Green et al.,
1988; Titzmann,
2014). There are different approaches to conceptualizing interracial climate, but it has generally been recognized as a multidimensional construct (Green et al.,
1988; Schachner et al.,
2019). Some researchers have defined this multifaceted construct as practices and norms shaped by teacher behaviors and peer interactions, respectively (Bellmore et al.,
2012). Although there is limited empirical research on the impact of interracial climate on friendship diversity, a positive perception of interracial climate has been linked to reduced ethnic discrimination (Bellmore et al.,
2012), better school performance and less behavioral concerns (Mattison & Aber,
2007), and more favorable perceptions of overall school climate (Green et al.,
1988). A closely related construct, cultural diversity climate (i.e., equitable and inclusive school practices promoting positive intergroup contact and embracing students’ diverse cultural backgrounds as a resource) has also been shown to promote school belonging and mental health (Ahmad et al.,
2018; Bardach et al.,
2024) as well as positive intergroup outcomes among students (Schwarzenthal et al.,
2017). Additionally, as proposed by contact theory, equal group status and positive intergroup attitudes are essential conditions for developing positive intergroup relationships in diverse settings (Pettigrew et al.,
2011). Grounded in these conceptual and empirical foundations, school interracial climate would likely facilitate friendship diversity.
The Moderating Role of Adolescents’ Immigrant Status
Guided by major developmental theories, including the integrative model for the study of developmental competencies in minority children (Coll et al.,
1996) and bioecological theory (Bronfenbrenner & Morris,
2006), the developmental processes of children and youth are influenced by the intersection between individuals’ social positions (e.g., culture, socioeconomic status, race/ethnicity) and contextual factors. The current study focuses on immigration status, recognizing that cross-racial/ ethnic friendships can be a particularly valuable resource for the positive adaptation and acculturation processes of youth from immigrant families (Titzmann,
2014). Adolescents from immigrant families, however, also often face more challenges in forming cross-racial/ethnic friendships. For adolescents from immigrant families, a preference for peers sharing the same racial and ethnic background (i.e., friendship homophily) is particularly salient due to cultural and language barriers with their native-born peers (Smith et al.,
2016; Titzmann & Silbereisen et al.,
2009). Although friendship homophily has been found to be conducive to immigrant adolescents’ development in some respects, including more positive health outcomes and adaptation (McMillan,
2019; Titzmann et al.,
2007), friendship homophily may simultaneously hinder them from developing skills needed for multicultural understanding, intergroup collaboration, and social adaptation (Titzmann,
2014).
Adolescents from immigrant and non-immigrant families may respond to school contextual factors (i.e., school diversity, interracial climate) differently, leading to varied behaviors and attitudes toward cross-racial/ethnic friendships. In the U.S., adolescents from immigrant families often possess intersecting disadvantaged positions, such as language barriers, lower socioeconomic status, cultural marginalization, limited social capital, more discriminatory experiences, and undocumented status (e.g., Metzner et al.,
2022). These intersecting marginalized identities, in turn, can lead youth from immigrant families to distrust outgroup members and view them as more of a threat, contributing to a greater preference for ingroup members than their counterparts from non-immigrant families, particularly in a highly diverse school, consistent with conflict and constrict theories (e.g., McLaren,
2003). Furthermore, owing to the heightened perceptions of threat from outgroup members, having a positive interracial climate would likely be particularly important for adolescents from immigrant families, as it helps them feel safer and gain more trust that facilitates cross-racial/ethnic friendships. To better understand the roles of school diversity and interracial climate and identify strategic practices to foster cross-racial/ethnic friendships for adolescents from different backgrounds, the interaction between adolescents’ immigrant status and school contextual factors in shaping cross-racial/ethnic friendships was investigated in the current study.
Discussion
Cross-racial/ethnic friendships play a vital role in fostering positive intergroup interactions and social adjustment among adolescents (Kelleghan et al.,
2019). However, intentional efforts are necessary to promote these friendships in schools, given adolescents’ tendencies to form friendships primarily with same-race/ethnic peers (Joyner & Kao,
2000), with this friendship homophily even more evident among adolescents from immigrant families (Smith et al.,
2016). Despite this need, there remains a limited understanding of the specific school contexts that facilitate cross-racial/ethnic friendships particularly in intersection with adolescents’ immigrant status. Thus, the present study employed a multilevel framework to investigate how school contextual factors, specifically school racial and ethnic diversity and peer and teacher interracial climate, were related to the racial and ethnic composition of adolescents’ close friendship networks and how these school characteristics interacted with adolescents’ immigrant status.
First, in alignment with some prior findings, positive associations between school diversity and friendship diversity were observed (Bohman & Miklikowska,
2021; Lorenzo et al.,
2024). The results empirically supported the hypothesis based on contact theory (Pettigrew et al.,
2011), indicating that schools with more racially/ethnically diverse populations provide a favorable condition for making cross-racial/ethnic friendships. The results also extended the prior findings by revealing important nuances about the effects of school diversity. The positive influences of school diversity diminished after reaching a certain diversity threshold, which aligns with the concept of “sufficient diversity” (Garces & Jayakumar,
2014). More research with larger school samples with greater school diversity ranges would help pinpoint the “sufficient diversity” threshold and clarify how much diversity is needed to achieve these positive effects. These findings reinforce prior research highlighting the advantages of school integration efforts in fostering positive intergroup relationships (Lorenzo et al.,
2024) and underscore the necessity for policymakers and administrators to work on diversifying school populations in the U.S.
Second, rarely has previous research considered the intersection of school contexts with students’ immigrant status on cross-racial/ethnic friendships. The current study’s findings observed that the impact of school diversity on friendship diversity also depended on students’ immigrant generational status. Contrary to the negative link between immigrant status and friendship diversity documented in some prior studies (Smith et al.,
2016; Titzmann & Silbereisen,
2009), a negative relation between immigrant status and friendship diversity was not found; however, compared to adolescents from non-immigrant families, adolescents from immigrant families reported greater friendship diversity in schools with low diversity but lower friendship diversity in schools with high diversity. Moreover, the positive relation between school diversity and friendship diversity was less pronounced among adolescents from immigrant families compared with adolescents from non-immigrant families. One potential reason for these seemingly divergent findings is the differing definitions of cross-racial/ethnic friendships. Most prior research on cross-ethnic friendships and immigrant vs non-immigrant youth drew from the concept of friendship homophily (Smith et al.,
2016; Titzmann,
2014) rather than friendship diversity as done in the current study. For instance, immigrant homophily in friendships was observed higher in classes with more same-racial/ethnic peers for immigrants but not native-born students (Smith et al.,
2016). Thus, the current findings are not necessarily contradictory to studies focusing on homophily; rather, students from immigrant families may be more likely to make more same- and cross-racial/ethnic peers in more diverse settings where they gain more opportunities to interact with same- and cross-racial/ethnic peers.
Regarding the differential responses of adolescents from immigrant and non-immigrant families to school diversity, the friendship diversity of adolescents from immigrant and non-immigrant families may develop differently in racially and ethnically diverse settings due to varying social perceptions influenced by social position. A highly racially and ethnically diverse setting may be perceived as more threatening and uncertain for immigrant youth due to the social complexities involved, resulting in more “hunker down” behaviors compared to non-immigrant adolescents who often possess more social resources, consistent with the constrict theory (Putnam,
2007). The interactive effects of adolescents’ social position (e.g., race and ethnicity, minority status, immigrant status) and school racial/ethnic composition for cross-racial/ethnic friendship have also been documented in a few past studies (e.g., Bagci et al.,
2014; Smith et al.,
2016). With increasing evidence suggesting that students with different social positions respond differently to the racial and ethnic composition of their schools, more research is needed to understand the factors contributing to these varying responses.
In considering the scant empirical research on which specific aspects of school climate promote friendship diversity among adolescents, the current study further examined the roles of peer and teacher interracial climate, taking adolescents’ immigrant backgrounds into consideration. The findings showed that favorable peer interracial climate was associated with more racially and ethnically diverse friendship networks among adolescents from immigrant families but not among adolescents from non-immigrant families, partially consistent with the proposed hypothesis based on contract theory (Pettigrew et al.,
2011) and the few empirically supported evidence (Ahmad et al.,
2018; Bellmore et al.,
2012). Conflict and constrict theories suggest that there is more distrust and perceived threat between groups in diverse contexts (Blalock,
1967; Putnam,
2007). Given the multiple disadvantaged social identities often held by immigrant adolescents (Metzner et al.,
2022; Suárez-Orozco et al.,
2015), it may be particularly significant for students from immigrant families to perceive their peers embracing welcoming and friendly norms to form cross-racial/ethnic friendships, as the positive peer interracial climate may reduce perceived intergroup distrust and threats and then encourage cross-racial/ethnic interactions. The mediating role of distrust and perceived threats in the relation between peer interracial climate and friendship diversity warrants further investigation to uncover the mechanisms. To help adolescents from immigrant families adapt to school environments and form diverse friendship networks, the findings imply that school administrators can work toward building an inclusive school culture that encourages peers’ openness to cross-racial/ethnic interactions and promotes respect and acceptance of various cultural backgrounds.
Interestingly, although it has been suggested that teachers play a crucial role in creating a positive school climate and promoting positive intergroup interactions (Cappella et al.,
2017; Green et al.,
1988), the current findings did not observe a link between teacher interracial climate and friendship diversity. It is possible that the perceived norms in peer interactions may have a more direct impact on adolescents’ friendship dynamics compared to norms fostered by teachers as shown by extensive evidence highlighting the direct impact of peer influences on friendship formation during adolescence (Laursen & Veenstra,
2021). In contrast, the influence of teachers on adolescent friendships appears to be indirect, mediated through teacher-child relationships and classroom management practices (Chen et al.,
2020; Serdiouk et al.,
2019). Another potential reason for the null findings relates to the study design. Adolescents’ perceptions of their teacher interracial climate from the previous academic year were used to predict their friendship diversity one year later. In U.S. high schools, students’ perceived teacher interracial climate may vary considerably from year to year because students typically interact with a new set of teachers after advancing to the next grade level. In contrast, their perceptions of interracial climate shaped by peers are likely more stable, given that they continue to interact with the same cohort of peers.
Strengths, Limitations, and Future Directions
Using a racially and ethnically diverse adolescent sample, the present study employed a multilevel framework to examine the links among school diversity, school interracial climate, and friendship diversity, which has been proposed to promote adolescents’ intergroup attitudes as well as long-term social integration. The nature of the data enabled us to disentangle the influences exerted at the school- and student-level, offering a better understanding of how each level impacts friendship diversity. The current investigation of the interaction between school contextual factors and adolescents’ immigrant status revealed that the impact of school diversity and school practices was contingent upon adolescents’ social position. These findings render insights into reconciling the divergent perspectives concerning the role of school diversity in intergroup interactions. Additionally, school interracial climate was conceptualized as a two-dimensional construct, providing some initial empirical evidence to identify specific aspects of school climate (peer vs teacher) that facilitate friendship diversity.
Despite these strengths and contributions, some limitations should be noted. First, the study defined immigrant status based on participants’ reports of their and their parents’ birthplaces. However, this study did not examine participants’ acculturation experiences or the combined effects of immigrant status with other language and cultural factors known to affect cross-racial/ethnic friendship formation, such as perceived cultural distance and language proficiency (Schachner et al.,
2015). Future research should delve deeper into how various language and cultural factors contribute to immigrant adolescents’ experiences in forming cross-racial/ethnic friendships in school. Second, perceived trust, power, and threats within school contexts may partially explain the differential effects of school diversity and interracial practices across adolescents from immigrant versus non-immigrant families, as suggested by extant theories (Pettigrew,
1998; Putnam,
2007). Future studies should investigate whether adolescents from different social positions perceived trust, power, and threats differently within the same context and whether these perceptions might mediate the impact of school contextual factors on forming cross-racial/ethnic friendships. Likewise, broader contextual factors, such as social norms and structures in different countries, could shape the influence of social positions and impact individuals’ and groups’ social interactions, potentially leading to different associations. Third, the bioecological framework proposes the dynamic interaction between different contexts in adolescent development (Bronfenbrenner & Morris,
2006); thus, examining practices in different contexts, such as cultural socialization in family and community social contexts, could reveal how these processes in various immediate settings shape adolescents’ friendship networks (Munniksma et al.,
2017; Wang et al.,
2020). Fourth, this study relied on self-reported perceived interracial climate, which was subject to individual experiences and subjective interpretation. With larger school samples and objective measures capturing interracial climate, future research can complement the current findings by identifying practices employed at the school or classroom level that promote cross-racial/ethnic friendships. Lastly, the current study did not inquire participants regarding their close friends’ immigrant status or other social identities. Therefore, it is unclear whether students from immigrant families tended to make friends with students also from immigrant backgrounds regardless of racial and ethnic differences. Future work utilizing qualitative methods may help further discern how social identities affect adolescents’ friendship formation.
Data Sharing Declaration
The data for the current study are not publicly accessible currently.
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