Does a Strong Bicultural Identity Matter for Emotional, Cognitive, and Behavioral Engagement?

: In the course of their acculturation process, minority students need to negotiate the adaption to the host society’s culture and the maintenance of the culture of their country of origin. This identity construction is complex and may encompass contradicting and competing goals. The adjustment to school is seen as a relevant acculturation marker. An increasingly prominent multidimensional construct is students’ school engagement because it can provide an insight into the way students feel and interact with the emotional, cognitive, and behavioral domains of school. Successful adjustment to school culture, and acculturation in general, can be closely related to school engagement. There is yet no common knowledge about the role bicultural national and/or ethnic identity plays for the three dimensions of school engagement. The present study focusses on minority students in Germany who report a strong bicultural identity (in comparison with single stronger ethnic or national identities, as well as weaker bicultural identiﬁcation) to explain students’ emotional, cognitive, and behavioral school engagement when controlling for gender, SES, and cultural capital. Data is derived from paper– pencil questionnaires administered in secondary schools in Germany. Regression analyses show that students with a stronger bicultural identity have a signiﬁcantly higher emotional, cognitive, and behavioral school engagement than their peers with a weaker bicultural identity, when controlling for gender, SES, and cultural capital. The results hint at the relevance of fostering students’ ethnic, but also their national, cultural identity to support their school engagement. Implications for teacher education are discussed.


Introduction
Due to several waves of historic migration, but also because of relatively recent developments in the possibility of global contact through travel and communication advances, Germany is becoming an increasingly culturally diverse country [1][2][3]. Although travel possibilities were limited within the last 1.5 years, intercultural contact via online media has expanded during the COVID-19 pandemic. Immigrant and non-immigrant members from various communities (or in this case, cultures) co-construct their daily life based on their sociocultural (virtual and offline) environment [4]. Minority youth who have migrated themselves or who were born in Germany are constantly confronted with the complex task of constructing their own multicultural identity, sometimes very overtly but often in a more underlying matter [5,6]. Within this process of acculturation, which is influenced by different agents and domains, schools represent a crucial institution of contact with the dominant majority culture, and therefore play one of the most important roles for students' identity construction [7][8][9][10][11]. A prominent acculturation component is school adjustment and achievement [12,13]. Despite the high school aspiration of immigrant families [14], students with a migration background tend to generally perform less well than their peers, as has been repeatedly proven in international student assessment studies [15].
It can be assumed that a better socio-cultural adjustment leads to higher achievement: school success is not just determined by the students' capacities and competencies, but by a number of other factors and resources related to the cultural and habitual proximity and knowledge of the respective school system [1,16], such as the parental and student's language proficiency, especially in regard to the cognitive academic language proficiency [1,17]. A prominent topic in acculturation research has been the question of the role students' cultural identities play in their school adjustment. Does a stronger ethnic or a stronger national identity matter? Is a strong bicultural identity a decisive factor within the academic domain? Because students' engagement with school is highly responsive to variations in their external factors such as their cultural milieu, their school (climate), teacher and peer relationships, and their internal factors such as their developmental competencies and their self-appraisal skills [18], and because it closely resembles their adjustment to school in general, we use engagement as an acculturation marker in this paper. School engagement is a multidimensional construct; most researchers agree on the three main dimensions of emotional, cognitive, and behavioral engagement. Although some studies have already tackled the topic of engagement and cultural identity, research has rarely investigated different profiles of cultural identity and different dimensions of students' engagement. The different types of engagement embody different kinds of involvement with school. The goal of this paper is to explore how different cultural identities could be interrelated with the three dimensions of engagement.

Bicultural Identity
Identity construction in general is an important developmental task [19,20]. In identity theory and research, it is agreed upon that there is not one identity, but that every individual owns a set of social identities [21,22]. A central social identity is the ethnic (cultural) identity, which derives from a person's cultural origin or heritage [23,24]. Van Oudenhoven and Benet-Martínez [20] state that "biculturals are individuals who have been exposed to and have internalized two or more sets of cultural meaning systems", (p. 48). Phinney et al. [25] understand that cultural identities are a result of "interaction[s] between the attitudes and characteristics of immigrants and the responses of the receiving society, moderated by the particular circumstances of the immigrant group within the society", (p. 494). From this proposal, one should assume that the construction of a cultural or multicultural identity is a reciprocal negotiation between the heritage and the target culture.
In acculturation research, one of the most prominent models for the explanation of a person's cultural orientation and negotiation between the heritage and majority culture is John Berry's acculturation model [10]. In this model, he differentiates between integration, separation, assimilation, and marginalization. Although this model still widely serves as a major indicator for the outcome of an acculturation process, as well as a policy marker, it has become evident that the construction of the individual's bicultural identity is a very complex lifelong process [23]. Still, Berry's model has been proven to be a firm acculturation attitude explanation and has been replicated in recent studies [26]. According to some researchers [25], a decisive factor for immigrant students' identity is not the respective policy in a country, but circumstances in their communities, which makes it even more challenging to grasp a generic acculturation model for adolescents. Those children and young adults need to switch between "different cognitive and behavioral frames tied to their different cultural identities", ref. [20], p. 47.
For immigrant adolescents, the expectations of both cultures can be experienced as challenging [27,28], especially in cases where the heritage family culture and the majority school culture are organized very differently (e.g., in terms of their complexity, their tightness, or their individualism or collectivism organization [29][30][31]). Additionally, cultural frame-switching can be performed more easily when the students' respective cultural identities are compatible [29]. The complexity of acculturation processes implies the difficulty of empirical measurements of acculturation and identity performance [26,32], and the question of what time frame migration research should be conducted in [33]. Although some models and a wide number of scales and qualitative approaches have been developed, there is no dominant method that is applied in most of the acculturation and cultural identity research [32]. Cultures contain an infinite amount of coded information that, on the one hand, must be interpreted and decoded by outsiders, while on the other hand, those outsiders actively co-construct the new joined culture [34]. Chirkov [34,35] argues that because of an acculturation gap, problems can evolve between the home and host cultural community. Immigrants enter new communities with certain expectations from their heritage culture. If those cultures differ to a great extent, the respective immigrant "may experience [ . . . ] mental correlates of acculturation stress. If the [immigrant] does not understand the causes of such states, [their] mental health may deteriorate and prevent [them] from attaining successful adaptation and acculturation", ref. [34], p. 15. Migrant youth do not only find themselves between their home culture and school culture-they also have the responsibility of navigating between the two and functioning as mediators [36], which can be a challenging task due to authority and responsibility disparities. It is important to mention that the gap between a student's home and their school's or individual teachers' sociocultural expectations is not limited to intercultural relations but can also exist in intracultural settings [37]. Nevertheless, since ethnic heritages embody an immense amount of beliefs, practices, customs, and/or languages, which can be very different from the majority culture, the question of how students embrace their ethnic and national identity and to what extent their identity might translate into school adjustment is crucial in the quest to create successful diversity-oriented classrooms and inclusive school settings.

Bicultural Identity and Well-Being
The acculturation process is often accompanied by certain stressors, which can affect an individual's psychological well-being [1,9,35,[38][39][40]. Experiences of discrimination along the way of acculturation can have severe negative effects [41][42][43]. The impact of stress and discrimination experiences can lead individuals into a disengaged state with the majority culture [10,44]. A person's ethnic identity (or racial identity) and the development of this part of one's social identity has been a popular research topic [45,46]. Mostly, researchers are interested in the role of an individual's ethnic identity in terms of their well-being or other similar constructs. A study by Balidemaj and Small [47] on the acculturation of Albanian-American immigrants in the United States shows that their acculturation, ethnic identity, and psychological well-being are positively correlated. The young adults' ethnic identity and acculturation affect their psychological well-being. Kim et al. [48] found among their group of first-generation Mexican immigrants that self-esteem was negatively affected by acculturative stress. They also found that ethnic identity exacerbated the negative effects of the two observed types of acculturative stress (American-based and Mexican-based) on psychological well-being. The role of a person's national identity within the process of ethnic identity construction and well-being has only sparsely been investigated. A national identification means that individuals feel an emotional involvement and connection to their resident country [49]. The national identification of minorities can depend on the perceived treatment of the respective group, leading to difficult conditions for some groups more so than others [50]. In general, the literature seems to promote the idea that the integration of a person's two (or more) cultural identities is an important antecedent of beneficial psychological outcomes [51][52][53]. People belonging to cultural minorities need to balance their cultural identities, but it is important to point out that whether they feel more connected to their heritage culture(s) and/or their majority national culture can differ in specific life domains [54].
When looking into well-being, acculturation, and the school domain, some research has already proposed the importance of a strong ethnic identity, but there is still a broad opinion that a strong cultural orientation towards an individual's ethnicity can also be associated with negative effects [22,55,56]. Makarova [57] confirmed the assumption that biculturally identified adolescents integrate better into the society of residence. Fuller-Rowell et al. [58] found interesting effects of ethnic identity and national identity as protective agents. Students' experiences of discrimination in the first year of college were positively associated with changes in ethnic identity commitment during their following college years among participants with a weaker national identity. This perceived discrimination was negatively associated with changes in ethnic identity commitment among those students who reported a stronger national identity. In addition, students with a strong national identity also had a greater increase in ethnic identity commitment. Phinney and Devich-Navarro [59] found evidence in their quantitative and qualitative study for a wide variation in the way adolescents identify with their ethnic and national cultures. Still, looking into the extreme group differences, about 90% of the students reported a combined bicultural identification, meaning that only 10% did not consider themselves belonging to two cultures. In their analysis of the PISA 2009 data, Edele et al. [60] found that more than half of students with an immigrant background feel a strong connection to Germany (integrated and assimilated group, cf. [61]), one third feels that they only belong to their ethnic heritage group (separated group), and about one fifth report not belonging to either culture (marginalized group). It is important to mention that there can be notable differences between ethnic groups; still, Molina et al. [62] found that, for most ethnic minorities, at least in the United States, higher perceptions of group discrimination were associated with lower levels of national identity and higher ethnic identity. Some research stresses the possibly problematic relation between heritage and national identity; Zander and Hannover [22] found in their German study that a strong identification with the culture of origin correlated with a rather marginal attachment to the host culture. Wolfgramm et al. [56] also proposed that one factor that can lead to a stronger connection with one's heritage is a perceived rejection, or the fear of being rejected, by the majority culture. These results are in line with the theory of rejection-identification [63], which states that when faced with discrimination, individuals' ethnic group identity increases and therefore serves as a protective agent. The protective power of a student's ethnic identity has also been proven by a recent study in Berlin; Kunyu et al. [64] found that students who had a strong heritage identity also reported a higher sense of socio-emotional and academic adjustment. An important factor that can have a moderating effect on discrimination experiences and well-being is a person's ethnic socialization; Harris-Britt et al. [65] found that when African American students received messages about race pride in their' socialization, it had a buffering effect on their discrimination experiences, and led to higher self-esteem, meaning that a strong ethnic identity, resulting from a positive ethnic socialization, can have a positive effect on well-being despite negative experiences directed towards the respective ethnicity. Spiegler et al. [66] were able to show that Turkish students in Germany who had strong ethnic identities and those who had medium ethnic identities both reported similar school adjustments, but the latter had lower school motivation. National identity was a mediator in both groups. Literature review of the relation between acculturation, bicultural identity, and well-being has proven that this topic is complex, and no general conclusion can be stated since research studies, as well as the respective heritage and host cultures, are very diverse. Still, most studies provide evidence for the importance of a strong ethnic identity to immigrants' well-being.

Bicultural Identity and School Engagement
Acculturation and the continuous construction of one's individual bicultural ethnic and national identity are influenced by different agents and domains, of which schools represent the central institution of contact with the dominant majority culture, and therefore play one of the most important roles for students' identity [7][8][9]11,49]. In the literature, educational success is widely considered as a marker for successful integration, alongside school adjustment [12,13]. Despite the overall high school aspiration of immigrant families [14], students with a migration background tend to perform less well than their peers [15]. There is a great amount of literature designed to answer the question of why there is an achievement gap between immigrant and non-immigrant students [1,67,68]. A comparatively new line of research points at students' sense of belonging as a main explanation for minority students' lack of success in academia [49,[69][70][71]. Students who do not feel that they belong might unconsciously distance themselves from the educational do-main. This can be a consequence of hegemonic practices in schools, but also discrimination experiences, and it might lead to stereotype threat experiences in school [72,73].
Within the last two decades, the concept of school engagement has been adopted by many researchers to explain the multidimensional commitment of students towards school. Students' engagement with school has become a widely recognized construct, because of its multidimensionality and ability to help explain students' paths between (hidden) dropout and school success [44,[74][75][76][77][78]. School engagement "provides a holistic lens for understanding how children interact with learning activities, with distinct behavioral, emotional-affective, and cognitive components" [18], p. 1087. The body of work around engagement has grown rapidly in the last decade, leading to a constantly evolving conceptualization of the construct [44,77]. Despite some other conceptual suggestions of engagement dimensions, most researchers agree on the three different but interrelated constructs of emotional engagement, cognitive engagement, and behavioral engagement [74]. The emotional, or affective, component of engagement towards school embodies students' positive and negative feelings towards school and learning. Behavioral engagement is related to the active participation in class and other school-related activities. Cognitive engagement means the willingness to invest in complex academic tasks (for an elaboration of the origin of the three dimensions cf. [79]). Deriving from acculturation theory, one could assume that all three dimensions of engagement should be related to better school adjustment. An emotionally committed student can transfer this attitude into their thoughts towards school and learning, and therefore, also express behavioral (active) participation. There is very limited research regarding the question of how different bicultural identities relate to the three dimensions of engagement. Nevertheless, there are reports on how immigrant and native students differ in terms of engagement. In their meta-analysis of studies and their biculturalism and well-being in the school context, with students from 41 countries, Chiu et al. [80] found that non-immigrant students did report a stronger emotional engagement (sense of belonging) with school, but a weaker cognitive engagement in comparison to their immigrant peers. This result hints at a difference between the three dimensions of engagement, as well as "conflicting theoretical relationships" (p. 14). Chiu and colleagues also found that there were differences between first-generation and secondgeneration immigrants, and there was an effect of the language spoken at home. Although engagement and acculturation are very broad constructs, the results of the meta-analysis indicate that acculturation types can have an impact on students' commitment to their school and learning.
Most of the research on school engagement, and on the specific dimensions of it, in the field of immigration/intercultural studies focuses on relevant predictors. Therefore, it is important to mention that one of the strongest influencing factors is the perceived support from teachers and schools [81][82][83][84][85]. Two studies based on the data in this paper have already revealed that support from teachers and the quality of the relationship between the student and teacher have an effect on students' emotional engagement, and that teachers can protect students from the consequences of experienced discrimination [44,86]. In particular, the role of diversity orientation within school has been proven to be a highly relevant factor in the development of students' well-being and engagement [87][88][89][90][91]. Abacioglu et al. [92] found that teachers who have strong multicultural attitudes can foster their students' school engagement.
The question remains whether a strong ethnic identity, a strong national identity, or the combination of both can predict school engagement, independent of the influence of teachers and school climate. School adjustment and bicultural identities have been investigated based on academic success markers such as academic self-concept, self-esteem, or test results or grades [26,93]. Hannover et al. [94] found that students who reported (by pictorial measure) a national (in this case German) school-related self-view performed better in standardized competence tests in reading comprehension in German than their peers who reported a stronger identification with their ethnic heritage group. Edele et al. [60] analyzed the PISA 2009 data and were able to show that immigrant students who had an integrated cultural identity performed statistically equally to their non-immigrant peers. In a recent study on bicultural identity, stereotype threat, and academic performance, Baysu and Phalet [93] were able to show that the effect of having a dual identity is complex and can lead to different outcomes depending on the respective threat. The authors found that students who identified with both identities outperformed their peers and reported higher self-esteem in low-threat conditions than their otherwise-identified peers in the control condition. However, in a high-threat context, having a dual identity came with costs: students reported more anxiety and they performed worse in comparison to the control condition. Those results point at the complexity as well as the importance of bicultural identity within the school context. Chu [95] found in her study that children who had stronger, more positive ethnic identities also had more positive academic attitudes. School engagement is thought to withstand situational effects, such as test results under stereotype threat conditions. Yet, it is still closely related to school performance. The existence of some contradictory findings regarding engagement and achievement [96] can add proof to the superordinated role of the construct; although school success is an important factor of successful acculturation and participation in the resident culture, it is not the only one. Feeling connected and belonging to one's social environment can have an equally important effect on a person's well-being and academic success.

The Present Study
A prominent topic in acculturation research has been the question "What role does students' cultural identity play in their school adjustment?" Does a strong ethnic or a strong national identity matter? Is a strong bicultural identity a decisive factor within the academic domain? Because students' engagement with school is highly responsive to variations in their personal and sociocultural factors [18], and because it closely resembles their adjustment to school in general, the present study focusses on engagement as an acculturation marker. Engagement can be divided into the three dimensions emotional, cognitive, and behavioral, which all interact with different kinds of academic areas, and which provide insight into the emotional attitude towards school, the willingness to engage in cognitive tasks, and the active participation in class and school-related areas. The advantage of the engagement construct is that it offers a glimpse into students' total engagement with their schools beyond their test results and their (final) grades. Referring to acculturation theory [10], we want to find out how different kinds of bicultural identities relate to the three dimensions of school engagement. With this paper we want to add to the understanding of bicultural identity and academic adjustment, and discuss the implications for schools, teachers, and teacher education.

Study Design
The present study is a cross-sectional paper-pencil questionnaire study with 7th grade students in North-Rhine Westphalia, conducted during the spring and summer of 2017 and 2018. The study is part of a larger international cooperative project focusing on the (hidden) school dropout of immigrants in different European countries and Israel. The data collection in Germany was carried out by the authors themselves and by trained student assistants. Data collection involved the completion of a structured questionnaire with one open question at the end ("Is there anything else you want to tell us?"). The questionnaire was completed individually during regular class time.

Analysis
With the software R [97] as well as IBM SPSS, we first conducted a factor analysis to estimate if our three engagement subdimensions of school engagement can be divided according to Fredericks et al. [79]. We explored differences between the four bicultural identity types using an ANOVA analysis with the three subdimensions of school engagement as the respective dependent variables. Further, we conducted multiple regression analyses in four single analyses to find out how much variance of the three subdimensions can be explained with the respective bicultural identity type as a predictor. Since immigrant families in Germany tend to have a poorer socioeconomic background, we controlled for the parents' highest International Socio-Economic Index of Occupational Status, as well as the families' cultural capital. In addition, we included gender as a control variable to find out whether there were differences between the two possible options (male and female) in the questionnaire (cf. [60] for a similar approach). The different sizes of bicultural identity groups (cf. Section 2.4) need to be considered when interpretating the following (exploratory) analyses.

Participants
The analysis of the present paper focuses on students who reported cultural selfidentification with at least one other culture, in addition to German culture. This subsample consists of 457 students (47.9% female), mostly aged 12-13 years [60.4%], with 21.2% older than 13, containing more than 30 different cultural identifications. In this analysis, we did only consider those students who reported themselves as belonging to at least one other culture than the German one. We included those students regardless of their migration background [44,86]. We did not divide the participants further into heritage groups because, on the one hand, the sample size would be too limited, and, on the other hand, there was no clear theoretical assumption that there would be strong differences between the present groups.

Bicultural Group Comparison
In this paper, the operationalization of bicultural students is based on the students' own reports of whether they feel that they belong to at least two cultures (ethnic/heritage culture(s) and/or national German culture). Furthermore, those biculturally identified students were asked to estimate the intensity of their sense of belonging to their national and ethnic identities. To compare students with stronger and weaker cultural identities we first conducted a split of the theoretical mean (3.5 on the 5-point Likert scale) of the ethnic identity scale and the national identity scale. It needs to be noted that both scales scored relatively highly, with students reporting rather strong national identities and very strong ethnic identities (cf. Table 1).
In the next step we allocated students into one of the four categories: stronger ethnic and stronger national identity (Es_Ns) (n = 112), stronger ethnic and weaker national identity (Es_Nw) (n = 219), weaker ethnic and stronger national identity (Ew_Ns) (n = 19), and weaker ethnic and weaker national identity (Ew_Nw) (n = 44). Due to the high mean of the two scales, the four groups did not turn out to be equally distributed. Despite this uneven group size, the theoretical split seems to represent a more realistic picture of students' actual identity than a statistical mean split. We assume that this form of categorization is therefore to some extent in line with the four acculturation dimensions suggested by Berry [10,98] (for a similar approach cf. Phinney and Devich-Navarro, ref. [6], also [60]), with students with stronger ethnic and stronger national identities belonging to the integration dimension, students with stronger ethnic and weaker national identities belonging to the separation dimension, students with weaker ethnic and stronger national identities belonging to the assimilation dimension, and students with weaker ethnic and weaker national identities belonging to the marginalization dimension. Since we only included students who reported belonging to an ethnic, heritage culture, the majority of the students did not fall into an assimilated or marginalized category. John Berry's model was proposed several decades ago, but it still represents the major acculturation dimensions used in this research, which have been empirically replicated many times in recent studies [66].

Measure
The scales and items used in the present study regarded students' gender, their cultural identifications (Q: Which culture or cultures do you feel part of?), their parents' occupation (using the HISEI measure; International Socio-Economic Index of Occupational Status) [99] and their families' cultural capital (adapted version from PISA, [15,100]) school engagement was measured with the engagement scale developed by Fredericks et al. [79], which can be divided into the three subscales of emotional, cognitive, and behavioral school engagement. Ethnic and national identity scales were based on Phinney et al. [101]. The scales and their characteristics are presented in Table 1.

Results
A confirmatory factor analysis was run to estimate whether cognitive, behavioral, and emotional engagement can be divided into the three dimensions of school engagement in our subsample. The analysis has shown acceptable model fit indices (TLI = 0.878; CLI = 0.892; RMSEA = 0.062; SRMR = 0.055). While the estimates of TLI and CLI are not good [103], the RMSEA and SRMR indicate a good model fit. Since the standardized factor loadings of school engagement for cognitive, behavioral, and emotional engagement are good (cognitive = 0.879; behavioral = 0.801; emotional = 0.795), school engagement was used as a construct with a cognitive, behavioral, and emotional dimension, as suggested by Fredericks et al. [79]. A one-way between-subjects exploratory ANOVA was conducted to compare the three subdimensions of school engagement under stronger ethnic and stronger national identity (Es_Ns), stronger ethnic and weaker national identity (Es_Nw), weaker ethnic and stronger national identity (Ew_Ns), and weaker ethnic and weaker national identity (Ew_Nw) conditions.
The ANOVA for the effect of bicultural identity for emotional school engagement was significant, F(3377) = 3.735, p = 0.011. Emotional engagement was normally distributed for the conditions Ew_Nw and Ew_Ns, but not for Es_Nw and Es_Nw, as assessed by the Shapiro-Wilk test (α = 0.05). Despite the different group sizes, the homogeneity of variances, asserted using Levene's Test, showed that equal variances could be assumed (p = 0.328). Post hoc analyses using the Tukey test for significance indicated that the mean sore for the condition Es_Ns (M = 2.648, SD = 0.73) was significantly different from the Es_Nw condition (M = 2.61, SD = 0.76, p = 0.006) (Figure 1). There were no other significant group differences. For cognitive school engagement, the analysis of variance showed that the effect of bicultural identity was significant-F(3380) = 2.937, p = 0.033. Cognitive engagement was normally distributed for the conditions Ew_Nw, Ew_Ns, and Es_Ns, but not for Es_Nw, as assessed by the Shapiro-Wilk test (α = 0.05). Despite the different group sizes, the homogeneity of variances, asserted using Levene's test, showed that equal variances could be assumed (p = 0.769). Post hoc analyses using the Tukey test for significance indicated that the mean sore for the condition Es_Ns (M = 2.684, SD = 0.65) was significantly different than the Ew_Nw condition (M = 2.356, SD = 0.67, p = 0.032) (Figure 2). There were no other significant group differences. There were no statistically significant differences in behavioral school engagement for the different groups of bicultural identity-F(3380) = 2.12, p = 0.097 (Figure 3). To further examine whether the bicultural identity types are predictors for the three dimensions of school engagement, simple linear regressions were carried out. Gender, HISEI, and cultural capital were added as control variables. Before running the regression, assumptions for the linear regression were tested. The assumption of a linear relationship between the independent and dependent variables was tested using the Rainbow test. Homoscedasticity was tested with the Levene test and Breusch-Pagan test. Furthermore, multicollinearity in the data was tested. With the Durbin Watson test, it was checked whether there was autocorrelation, and a Cook's distance test was used to identify critical outliers. All assumptions were met to a satisfactory level regarding the present exploratory analyses. The histograms hint at a normal distribution for emotional school engagement and cognitive school engagement, while behavioral engagement showed a slight left skew. For each dimension of school engagement, five regression analyses were run, one for each condition of bicultural identity including the control variables, as well as one regression including only the controlling variables as predictors. A Bonferroni correction of the predictors has shown that all presented significant p-levels remained significant at the 0.05 level. The results of the regression analyses are shown in Table 2 below. The first analysis, and 0 model of the following analyses, shows that among the three predictors of gender, HISEI, and cultural capital, only the last one was significant throughout all analyses. Model 0 with only the controlling variables as predictors (F(3395) = 9.39) described 5.9% of the variance in emotional engagement. Model 1a with bicultural identity Ew_Nw as the additional predictor (F(4337) = 5.87) described 5.4% of the variance. Model 1b with the controlling variables and the condition Ew_Ns as predictor (F(4337) = 5.69) described 5.2%. Model 1c (F(4337) = 6.42) described 6% of variance, while Model 1d (F(4337) = 7.82) described 7.4% of the variance. Only the extreme group with bicultural identity Es_Ns was a significant predictor for emotional engagement. The results indicate that students with a stronger ethnic and national identity had higher emotional engagement than students in the other conditions. Students with a strong cultural capital score also reported higher emotional engagement than those with a lower cultural capital score.
A regression with the same predictors was calculated for the dependent variable cognitive engagement (Table 3). Model 0 with the controlling variables as predictors (F(3396) = 14.56) described 9.3% of the variance of school engagement. Model 1a with bicultural identity Ew_Nw as the additional predictor (F(4338) = 11.30) described 10.8% of the variance. Model 1b, with the controlling variables and the condition with Ew_Ns identity as predictors (F(4338) = 10.08), described 9.6%. Model 1c (F(4338) = 9.91) described 9.4% of variance, while Model 1d (F(4338) = 11.10) described 10.6% of the variance. Cultural capital and the condition of bicultural identity Ew_Nw, as well as Es_Ns, were significant predictors for cognitive engagement. The results indicate that students with a stronger ethnic and national identity reported a stronger cognitive school engagement in comparison to all other conditions. Students with a high cultural capital score had a higher cognitive engagement than those with a lower cultural capital score. The results for behavioral engagement are similar to the results of the previous regression with school engagement as the dependent variable (Table 4). Model 0, with only the controlling variables as predictors (F(3397) = 14.34), described 9.1% of the variance of behavioral engagement. Model 1a with bicultural identity Ew_Nw as the additional predictor (F(4338) = 8.33) described 7.9% of the variance. Model 1b, with the controlling variables and the condition of Ew_Ns identity as predictors (F(4338) = 8.85), described 8.4%. Model 1c (F(4338) = 8.31) described 7.9% of variance, while Model 1d (F(4338) = 9.46) described 9% of the variance. Only the extreme group with both strong identities could explain the additional variance of behavioral engagement. Cultural capital and the conditions of stronger ethnic and national bicultural identity were significant predictors for behavioral engagement. The results indicate that students with stronger ethnic and national identities had stronger behavioral engagement than students in the other conditions. Students with a high cultural capital score reported a better behavioral engagement than those with a lower cultural capital score. Students with weaker bicultural identities showed weaker behavioral engagement than students in the other conditions.

Discussion
Acculturation research has already shown that a person's or even a group's bicultural identity is a relevant parameter for successful integration into and adjustment to a new society. School adjustment and school success in general can serve as acculturation markers. Despite the overall high educational aspirations of immigrant families, immigrant students tend to perform less well at school than their peers who belong to the majority culture. From recent research, it is known that students who feel that they belong in school tend to be better adjusted, report more self-esteem, and experience more school success. Although research is not unambiguous regarding school success and acculturation profiles, the majority of the literature suggests that employing a strong national as well as strong ethnic identity could be beneficial for school success [60,94]. The question of whether a stronger ethnic or national cultural identity, or dual strong identity, is beneficial for different dimensions of school engagement has been only marginally addressed in acculturation research.
The results of the present analyses show that for all school engagement dimensions, having a stronger ethnic and national identity seems beneficial. This finding confirms a wide array of acculturation research, which hints at integration (stronger bicultural identity) as being predictive for positive school outcomes [26,[51][52][53].
Although closely interrelated, the three dimensions of school engagement can mean different outcomes for students. In the presented analyses, a stronger ethnic and national bicultural identity was a significant predictor for all three engagement dimensions. In fact, the respective coefficients of the bicultural groups only slightly differ among the three school engagement dimensions. While for students with a weaker bicultural identity, there is a negative association with all dimensions of school engagement, for students with a stronger bicultural identity there is a positive connection. There were no major differences between the three engagement types, which, on the one hand, certainly hints at the close interrelation of the constructs. On the other hand, the three dimensions might need to be assessed differently in order to better understand the patterns of engagement and identity within school. Additionally, it is important to mention that the four groups differed in size, and the respective explained variances in the models were relatively small, hinting at other important factors that need to be explored in future research.
When translating the present findings into practice in schools, one could assume that students who do not feel sufficiently connected to either their heritage culture or their host society might have difficulties when it comes to their active willingness to engage in tasks in school. This could, in turn, lead to lower achievements. It has to be taken into account that the four bicultural identity groups in this paper were created by allocation to four groups based on a theoretical mean split. The overall means of ethnic and national identity scales were relatively high, which means that, at least in the present sample, immigrant students feel strongly connected to their heritage culture, but also to their national culture. Future research that wants to explore the connection of students' bicultural identity to engagement might need to provide a more nuanced picture of acculturation profiles. Furthermore, the proximity of heritage and host culture might be integrated as a relevant predictor for the identification [20,21], and respective cultural groups should be systematically selected in the sampling process. When considering the proximity of the heritage and national identity, a strong identification with both cultures might have differential predictive power in explaining school engagement [20]. An additional qualitative approach to this aspect should be applied in future research to provide a more holistic, in-depth analysis of students' experiences.
In the present analysis, neither gender nor the parents' occupation has an effect on school engagement. Since the parental occupation was reported by the students themselves, the assessment might have been difficult for them, and an objective measure. might not have been obtained Nevertheless, the strongest predictor was the families' cultural capital, stressing the importance of cultural possessions and practices in the family. Cultural resources have been shown to be a decisive factor within the acculturation process [40]. Schools should cooperate with families and provide them with the necessary resources, such as targeted information about school-related issues, and opportunities to engage parents in their children's learning and school activities to provide more equal learning opportunities for all students.
In conclusion, the findings of this paper advocate for the support of the development of students' integrated bicultural identities when school engagement is at stake. Numerous studies have contributed to our understanding of school engagement by emphasizing the importance of supportive teachers and inclusive school climates, especially for immigrant children [44,83,84,86]. To foster a strong and integrated bicultural identity in students, teaching, and schools in general, need to be diversity-oriented and inclusive [1,86,104]. Especially in cases where cultural expectations between the child's heritage and the host community/school differ from each other, teachers should support their students and navigate them in finding a harmonious blended bi-or multicultural identity. The support of students' identity development is not limited to ethnic and national identities but can be expanded to other kinds (such as a European identity).
In recent years, school interventions have been implemented predominantly in the United States, but also in Germany, to enhance students' ethnic identity, their academic selfconcept, and their belonging [105][106][107]. Intercultural education has become more present in the discussion of teacher education [1,87], and the empirical evidence is relatively strong in favor of multicultural and diversity-orientated teaching and learning [90,92,[108][109][110][111]. Teachers and pre-service teachers need to be further provided with practical information and material on how to foster their students' identity and establish an inclusive climate within their class and school.
Author Contributions: Both authors contributed equally to the manuscript. All authors have read and agreed to the published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: Ethical review was not carried out for this questionnaire study since the items used within the questionnaire study were based on validated scales, and therefore did not require further ethical investigation. Furthermore, the inclusion of an ethics committee is not common within the department. The study was reviewed by an officer from the protection of data security department at the University of Duisburg-Essen. The officer reviewed the questionnaire and data handling process in terms of the general data protection regulation from 2018 (DGSVO/GDRP).

Informed Consent Statement:
Informed consent was obtained from all subjects involved in the study.

Data Availability Statement:
Datasets are not stored online. In case of any inquiry regarding the data, the authors may be contacted.

Conflicts of Interest:
The authors declare no conflict of interest.