Bullying Victimization Due to Racial, Ethnic, Citizenship and/or Religious Status: A Systematic Review

A resurgent climate of nationalism, racism, xenophobia, anti-Semitism, and Islamophobia in many parts of the world has drawn attention to the risk of bullying victimization among racial, ethnic and/or religious minority youth. However, no attempt has yet been made to synthesize the literature on this topic to derive better understanding and guide future prevention and intervention efforts. The aim of this study was to conduct a systematic review of the literature on individual, school, family, and community -level factors and outcomes associated with racist bullying victimization. Systematic searches of EBSCOhost, Scopus, ASSIA and Web of Science databases identified 73 articles that included quantitative and qualitative analyses on this topic. Overall, this review found that negative stereotypes and discrimination operating in school and community contexts put racial/ethnic minority, immigrant, and refugee youth at an increased risk of racist bullying victimization. The review also found that racist bullying victimization is associated with a wide range of negative outcomes including poor mental health, lower academic engagement, and an increased risk of involvement in delinquent behaviours, especially among older pupils. The review identified several gaps in the research, including the lack of adequate theorization and the infrequent consideration of potential mediators and moderators. Finally, the review outlined future directions, such as the need to study how intergroup processes influence racist bullying victimization.


Introduction
A resurgent climate of nationalism, racism, xenophobia, anti-Semitism, and Islamophobia in many parts of the world, has drawn attention to the phenomenon of racist bullying. (Huang & Cornell, 2019). Racist bullying is defined as bullying motivated by prejudice against someone's actual or perceived race, ethnicity, culture, citizenship status or religion (Tippett et al., 2010). To date, there has been no systematic analysis and synthesis of the empirical evidence to determine the factors and outcomes associated with racist bullying victimization. Without this knowledge it is not possible to know confidently what contributes to racist bullying victimization and how it can be challenged effectively. This study addresses this gap by systematically reviewing the empirical evidence on individual, school, family, and community-level factors and outcomes associated with racist bullying victimization.
Bullying, that can happen face to face or online, is recognised as a global public health, educational and mental health issue that can have a long-lasting negative impact . While many aspects of bullying are well studied in the literature, racist bullying has only recently gained attention in the literature as a specific subtype of bullying (Xu et al., 2020). Yet a growing body of research demonstrates that racist bullying is experienced by large numbers of racial, ethnic and/or religious minority youth in schools (Gönültaş & Mulvey, 2021;Huang & Cornell, 2019). Considering this evidence, it is important to gain insight into the factors and outcomes associated with racist bullying victimization to reach a better understanding of negative pathways and help guide future interventions in ethnically and culturally diverse school contexts.
In the general bullying literature, Bronfenbrenner (1977)'s ecological systems theory has been applied to frame bullying as a socio-cultural phenomenon that is influenced not only by individual characteristics of the child but also school, family, and community factors. This theoretical perspective views child development as a complex system of interactions influenced by multiple levels of contexts from those closest to the child (family, school) to those furthest away (community). However, it remains unclear what factors at what level have the most consistent associations with racist bullying victimization.
Furthermore, while there are many systematic reviews of outcomes associated with general bullying victimization, there has been no systematic investigation of the negative outcomes associated with racist bullying victimization. This is an important gap as some emerging evidence suggests that racist bullying is more harmful compared to general bullying as it is targeted at a person's racial, ethnic, cultural and/or religious identity that is internal, stable, and uncontrollable (Jones & Rutland, 2018;Menesini & Salmivalli, 2017). Furthermore, as racist bullying occurs in an intergroup context it has the potential to affect not only a person's academic performance, self-esteem and/or mental health but also their racial/ethnic/religious identification and hostility towards outgroup members (Benner & Graham, 2013). However, it is not currently known what outcomes are most consistently associated with racist bullying victimization across multiple domains.
The lack of a comprehensive review of the empirical evidence on factors and outcomes most consistently associated with racist bullying victimization hampers the design of empirically based interventions. Among the existing few systematic reviews and meta-analyses that consider race, ethnicity, citizenship, and religion in relation to bullying, the focus has been on reviewing ethnic/racial differences in the prevalence of bullying with inconsistent findings (Álvarez-García et al., 2015;Vitoroulis & Vaillancourt, 2015. More recently, there was a review of contextual-level risk factors associated with bullying among racial and ethnic minority youth (Xu et al., 2020). However, this review did not distinguish whether the bullying experienced was due to someone's perceived race or ethnicity or due to other reasons. To address this gap and call more attention to the phenomenon of racist bullying, the present study systematically reviewed the empirical evidence on individual, school, family, and community-level factors and outcomes associated with racist bullying victimization.

Current Study
There is a need to systematically assess the evidence on what individual, school, family, and community-level factors influence racist bullying victimization. Also, there is a need to systematically examine outcomes associated with racist bullying victimization. This study addresses these gaps by systematically reviewing the empirical evidence on individual, school, family, and community-level factors and outcomes associated with racist bullying victimization. Systematically reviewing this evidence can improve understanding of multilevel pathways and outcomes associated with racist bullying victimization that can then, in turn, help inform more effective interventions at multiple levels. It can also help highlight which factors at different levels have been most consistently associated with racist bullying victimisation and which factors have been less studied. In doing so, it can advance theory development in the field.

Search Strategy
The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Moher et al., 2009). An electronic search was carried out between 20th May and 2nd June 2019 on EBSCOhost, Scopus, ASSIA and Web of Science databases for both quantitative and qualitative empirical studies published in English in scientific journals with no restriction of publication year. To update the review, the search was repeated on 9th March 2021 to cover any research published between 2019 and 2020. The review was last updated on 17th August 2022 to cover any research published between 2021 and 2022. The search terms used were organised into four categories: (a) prejudice related terms, such as "prejudice", "stigma", "bias", "discriminat*", (b) bullying related terms, such as "bullying", "bull*", "victim*", "perpetra*", "aggressor*", "bully-victim", "peer victimization", "school violence", "aggression", "peer harassment", "youth violence", (c) minority membership terms, such as "rac*", "ethnicity" "minorit*", "muslim*", "asian*" and, finally, (d) age related terms, such as "child*", "youth", "high school". The searches were conducted combining Title and Abstract in all 4 databases. The saved searches were uploaded to Covidence for storage and screening purposes.

Inclusion and Exclusion Criteria
Studies were included if: (1) they examined bullying victimization that occurred because of or based on a person's race, ethnicity, religion or citizenship status, (2) they considered bullying and cyberbullying that occurred before the age of 18 taking place either in schools and/or in other youth environments such as sports/after school clubs, (3) the source of information for bullying occurring among peers was the children and young people involved or their peers, teachers, parents/carers, or other adults, (4) they measured at least one correlate of bullying victimization due to race, ethnicity, citizenship status and/or religion and 5) they employed a quantitative, qualitative or mixed-methods design.
The following studies were excluded: (1) purely theoretical studies that did not empirically assess factors and/ or outcomes associated with racist bullying victimization, (2) literature-based studies such as literature reviews and systematic reviews, (3) unpublished studies such as dissertations/theses, (4) publications published in formats other than scientific journals such as conference proceedings, editorials, books, (5) studies published in languages other than English, (6) studies that focused on bullying among adults or involved an adult as perpetrator or victim and (7) studies that focused on bullying among members of different national, racial, cultural, ethnic, religious groups but where the motivation or basis for the bullying is unknown.

Data Collection
As shown in Fig. 1, the literature search yielded 5383 potentially eligible publications. After duplicates were removed, 2921 studies remained. After the titles and abstract of these publications were screened against the inclusion and exclusion criteria, 478 references were identified as potentially relevant and retrieved in full text. In the next step, the full text of the 478 articles selected was screened independently by LDA and MS. Any disagreement was resolved by consensus with a third reviewer (LV). Following the full text review, 62 studies were selected for inclusion in the review. An additional 11 articles were added via reference list checking, bringing the total of included studies to 73 (see Fig. 1). The two reviewers agreed upon the final 73 articles to be included. Data were extracted by one reviewer (MS) and checked for accuracy by a second reviewer (LDA).

Coding Strategy
Finally, the following information was extracted from each article that met the inclusion criteria: (a) authors and year or publication; (b) country; (c) characteristics of the participants (sample size, gender, ethnic/racial or religious group and age or grade); (d) methodological design, including the definition and measure used to investigate bullying due to racial/ethnic, citizenship and/or religious status; (e) theoretical framework adopted in the study if any and (f) main findings on individual, school, family, and community -level factors and outcomes associated with racist bullying victimization.
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used as guidelines for reporting the selected articles.

Quality Appraisal
Included studies were assessed for quality using the Quality Assessment Tool for Studies with Diverse Designs (QATSDD; Sirriyeh et al., 2012). This instrument contains a list of criteria for quantitative, qualitative, and mixed methods research designs rated on a four-point scale, ranging from 0 (not at all) to three (complete). A percentage for each study was calculated for standardisation purposes by dividing the total score for each study by the maximum possible score. Table 1 presents all studies reviewed along with quality percentages. Inter-rater reliability between reviewers, assessed across 10% of included studies, was excellent (k = 0.90).

Results
Forty-eight articles out of 73 (66%) were published between 2012 and 2022. Overall, 70% (51 studies) of studies investigated individual-level factors associated with bullying victimization due to race, ethnicity, citizenship status and/ or religion. School-level factors were considered by 47% of articles (34 studies), family-level factors by 5% of studies (four studies) and community-level factors by 23% of articles (17 studies). Finally, outcomes associated with racist bullying victimization were considered by 37 studies (51% of studies included). Key information about the studies included in this review is presented in Table 2. This table depicts the country where the study was conducted, characteristics of the sample, the method used, and type of bullying involvement measured. A full reporting of measures and theoretical frameworks used in each study can be found in the supplemental materials.
The next part of the results section describes the main findings of studies that have investigated individual, school, family and community-level factors and outcomes associated with bullying victimization due to race, ethnicity, citizenship status and/or religion (see Table 3).

Individual-Level Factors
The following individual-level factors associated with bullying victimization due to race, ethnicity, citizenship and/ or religion were investigated in 51 studies included in this review.

Age
Only one study investigated age differences in bullying victimization due to ethnic/racial differences. The study found that younger adolescents were more at risk (Monks et al., 2008).

Religious Minority Status
Seven studies found that wearing a religious covering or visibly practising one's religion as visible indicators of religious minority status were associated with bullying victimization. This involved Muslim and Sikh youth in the USA (Aroian, 2012;Atwal & Wang, 2019), non-Christian youth in the USA (Dupper et al., 2015), Muslim and Christian youth in the UK (Crozier & Davies, 2008;Moulin, 2016), Jewish children and adolescents in Australia (Gross & Rutland, 2014) and Muslim youth in Estonia, Finland, and Sweden (Schihalejev et al., 2020). Quality assessment criteria: 1 = explicit theoretical framework; 2 = statement of aim(s)objectives in main body of report; 3 = clear description of research setting; 4 = evidence of sample size considered in terms of analysis; 5 = representative sample of target group of a reasonable size; 6 = description of procedure for data collection; 7 = rationale for choice of data collection tools; 8 = detailed recruitment data; 9 = statistical assessment of reliability and validity of measurement tools (quantitative only); 10 = fit between stated research question and method of data collection (quantitative only); 11 = fit between stated research question and format and content of data collection tool (e.g., interview schedule) (qualitative only); 12 = fit between research question and method of analysis; 13 = good justification for analytical method selected; 14 = assessment of reliability of analytical process (qualitative only); 15 = evidence of user involvement in the design; 16 = strengths and limitations critically discussed. Studies were scored depending on the degree to which the specific criteria were met ("complete" = 3 "moderately" = 2; "very slightly" = 1; "not at all" = 0). A summary score was calculated for each article by summing the total score obtained across relevant items and dividing by the total possible score (for a complete description of the score computing procedure, see Sirriyeh et al., 2011) Children reported reacting to being called names with sadness, feeling hurt, or feeling upset  Galán et al. (2021) Compared with uninvolved youth, youth experiencing bullying due to race/ ethnicity/national origin were at increased risk for non-suicidal self-injury, suicidal ideation, exposure to violence, sexual assault, and adolescent relationship abuse. These same youth were also more likely to forego medical care (i.e., not go to the emergency department when needed) and go more than 2 years since their last routine well visit More likely to also report identity-based bullying perpetration 31 Garza Ayala (2022) Being bilingual and speaking a second language in school 32 Goldweber et al. (2013) Being a victim of school bullying, especially in urban areas was associated with increased likelihood of being racially bullied Urbanicity was associated with the increased likelihood of having been racially bullied 33 Gower et al. (2015) In schools where discipline problems were frequently reported there was increased odds of race/ based bullying The proportion of students feeling unsafe at school was a risk factor of race and religious-based bullying Ethnic minorities Victims reported long-lasting self-hatred, feeling helpless, embarrassed and anxious.
Tried to cope by fitting in and making changes to their hair Victims reported hating school  (2015) Participants did not report their victimization to school authorities First-generation immigrants.

Gypsies
Strong positive relationship found between personal and ethnic-cultural multivictimization

Intersectionality
Two studies (Bucchianeri et al., 2016; reported that having other stigmatized characteristics such as being LGBTQ or having a disability increases the risk of bullying victimization due to race, ethnicity, citizenship status and/or religion.

Linguistic Diversity & Acculturation
Four studies found that speaking one's own language at school (Garza Ayala, 2022; Haavind et al., 2015) or at home (Schihalejev et al., 2020;Yu et al., 2003) was positively associated with bullying victimization due to race, ethnicity, citizenship status and/or religion. In another study, participants reported that trying to learn the local language better was a way of protecting themselves from the risk of bullying victimization due to racial, ethnic, citizenship and/or religious differences (Dovchin, 2020). In Italy, Palladino et al. (2020) found that a strong acculturation towards the host country protected students from bullying victimization due to race, ethnicity, citizenship status and/or religion. However, this protective effect was moderated by citizenship status.

School-Level Factors
The following school-level factors associated with bullying victimization due to race, ethnicity, citizenship and/or religion were investigated in 34 studies included in this review.

Ethnic School Composition
Two studies reported that ethnic school composition moderated the relationship between ethnic/immigration status and racist bullying victimization. In one study, ethnic majority children were more likely to be bullied because of their race/ ethnicity when they were the numerical minority in their school as size of group changed power differentials (Durkin et al., 2012). In another study, second generation immigrants were less likely to be bullied in moderately concentrated schools (Vitoroulis & Georgiades, 2017).

Institutional Racism
A strong theme that emerged mainly from qualitative studies is that the youth who experienced bullying victimization due to ethnic/racial, citizenship and/or religious differences, as well as their parents, felt that their teachers were dismissive and even, at times, contributed to the perpetuation of stereotypes and bias in the classroom (Baker et al., 2001;Bešić et al., 2020;Bloomer et al., 2014;Chong et al., 2009;Coffin et al., 2010;  Gross & Rutland, 2014;Liang et al., 2007;Lloyd & Stead, 2001;Page, 2020;Qin et al., 2008;Rosenbloom & Way, 2004). In one US study, adolescents from refugee backgrounds reported that they were not willing to report their victimization to the school authorities, as they did not trust they would do anything (Mthethwa-Sommers & Kisiara, 2015). In another Canadian study, disparaging reactions from teachers led students to accept their victimization as "normal" (Varma-Joshi et al., 2004). In one study, participants perceived formal aspects of schooling to be biased against Christian beliefs and practices (Moulin, 2016). The importance of respect for cultural diversity was emphasised also in another Canadian study according to which a stronger sense of school belongingness and perceived teacher support for cultural diversity reduced ethnic/racial bullying victimization (Vitoroulis & Georgiades, 2017).

Perceived School Violence
One study found that bullying victimization due to ethnic/racial and/or religious differences is more frequent in schools where there is a higher risk of being threatened with a weapon or having property damaged and where there is a higher proportion of students reporting feeling unsafe (Russell et al., 2012). Another study found that there were increased odds of ethnic bullying victimization in schools where discipline problems were frequently reported and where there was a higher proportion of students feeling unsafe at school (Gower et al., 2015). Eight studies found that those bullied due to their race/ethnicity and/or religion are more likely to self-report, or identified by their peers as, being victimized by peers for other reasons (Arens & Visser, 2020;Felix et al., 2009;Goldweber et al., 2013;Hunter et al., 2010;Mendez et al., 2016;Rodriguez-Hidalgo et al., 2014;Seaton et al., 2013) and/or experiencing other forms of physical, sexual and verbal victimization at school (Felix & You, 2011).

Peer Relationships
Two studies found that ethnic/racial minorities were more likely to be bullied due to their ethnicity/race if they chose to associate with peers from an ethnic group other than their own (Coffin et al., 2010;Qin et al., 2008).

School Composition
In the USA, one study found that having more LGBTQ peers in school lowered the risk of bullying victimization due to race/ethnicity and/or religion for LGBTQ youth (Gower et al., 2021).

Family-Level Factors
Only four out of 73 studies investigated family-level factors and their associations with bullying victimization due to ethnic/racial, citizenship and/or religious differences. An Australian study reported a positive association between racist bullying and authoritarian parents that encouraged victims to fight back (Coffin et al., 2010). Further, a Canadian study showed there was a positive correlation between disparaging comments from minority parents that reinforced the view that victimization is "normal" and to be expected and ethnic/racial bullying victimization (Varma-Joshi et al., 2004). Finally, in Finland, higher rates of parental depression were found among victims of racist bullying after controlling for age and gender (Holmgren et al., 2019).
Regarding the effect of family socioeconomic status on racist bullying victimization, results are mixed. A study conducted in South Africa (Das-Munshi et al., 2016) reported that adolescents from low SES families were more likely to be victimized due to ethnic/racial and/or religious differences. In contrast, in a Finnish study investigating racist bullying victimization among international adoptees, low family SES was not a statistically significant predictor (Holmgren et al., 2019).

Community-Level Factors
The following community-level factors were investigated in relation to bullying victimization due to ethnic/racial, citizenship and/or religious differences in 17 studies included in this review.

Community Diversity
One Canadian study found that individuals in the ethnic minority in a community were more likely to be victimized than individuals of the same ethnicity in a community where they were the majority (Schumann et al., 2013). The same study found that community ethnic diversity, as signified by the presence of ethnic-focused Christian religious buildings, was positively associated to ethnic/racial bullying victimization. In contrast, the presence of non-Christian religious buildings was related to decreased prevalence of ethnic/religious bullying victimization (Schumann et al., 2013).

Stereotypes
Twelve studies found that bullying victimization due to ethnic/racial, citizenship and/or religious differences is higher in communities where ethnic/racial and religious stereotypes have developed due to negative media representations of ethnic and religious minorities in the aftermath of events, such as 9/11 and the Iraq war (Baker et al., 2001;Banerjee et al., 2020;Bešić et al., 2020;Chong et al., 2009;Coffin et al., 2010;Crozier & Davies, 2008;Dupper et al., 2015;Haines-Saah et al., 2018;Liang et al., 2007;Lloyd & Stead, 2001;Moulin, 2016;Page, 2020). In one US study, victims reported being bullied due to their race, ethnicity and/or religion also by adults in other contexts showing the pervasiveness of racism in the community (Albdour et al., 2017). One Australian study found that Jewish students' victimization related to anti-Jewish stereotypes perpetuated in peers' families (Gross & Rutland, 2014).

Poverty
Evidence on the relationship between bullying victimization due to racial, ethnic and/or religious bias and poverty is mixed. One study reported that bullying due to ethnic/racial differences is higher in low-socioeconomic communities (Coffin et al., 2010), whereas another found victimization due to racial/ethnic and/or religious differences to be equally high in upper-and lower-income school districts (Aroian, 2012). One US study reported that living in an urban area was associated with an increased likelihood of ethnic/racial bullying victimization (Goldweber et al., 2013).

Community Violence
A US and a Canadian study reported bullying victimization due to ethnic/racial differences is more prevalent in communities where violence, victimization and substance abuse is common (Chong et al., 2009;Schumann et al., 2013).

Outcomes
The review found evidence of the following outcomes associated with racist bullying victimization.
Four studies investigated whether attributions of race, ethnicity and/or religion exacerbate the relationship between peer victimization and psychosocial adjustment with mixed findings. A US cross-sectional survey (Russell et al., 2012) found that mental health issues and substance misuse levels were worse among youth reporting victimization due to racial/ethnic differences than among those reporting general victimization. Also, in the UK, a study found that bullying due to race, ethnicity and/or religion correlated more strongly with depression than general bullying partially by increasing feelings of perceived threat, however a stronger ethnic/religious identity buffered against it (Hunter et al., 2010). Finally, a US study found that victims of ethnic but not religious bullying were significantly more likely to report a high-severe emotional impact compared to general bullying victimization especially when female (Mendez et al., 2016). In contrast, one cross-sectional survey in the US (Gusler & Kiang, 2019) found that attributing victimization to skin colour/ethnicity did not exacerbate the relationship between peer victimization and poor psychosocial adjustment.
Only two studies investigated whether coping strategies moderated the effect of bullying victimization due to racial, ethnic, citizenship and/or religious status on mental health. Helpful coping strategies found to lessen the emotional impact of ethnic bullying victimization were filtering out negative reactions, staying indifferent, making a joke about it, and connecting online with existing friends (Banerjee et al., 2020;Mendez et al., 2016). A large-scale study conducted in the USA found that only 24% of youth indicated that "telling an adult at school" made things better. In the same study, males were significantly more likely than females to report "fighting back" as a coping strategy, and more likely to report it was effective (Mendez et al., 2016). In another study conducted in India with expat kids from South Asia the findings indicated that most of the study's participants could cope with instances of ethnic bullying victimization by "creating a cocoon of indifference around themselves" and by systematically filtering out any negative reactions (Banerjee et al., (2020, p. 285). In the same study, participants spoke of how they tried to stay indifferent to the bullying they experienced and take any inappropriate comments sportingly rather than feeling antagonistic to their peers. Some respondents stated that this strategy helped them dilute the situation and gain respect from their host country's peers. The other main strategy that helped expat kids cope was using social networking media to keep in touch with their extended friend network in their home countries while they struggled to form friendships in their host country.

Physical Health
One study reported that in one case racist bullying victimization had resulted in hair loss (Page, 2020). Another study with an adolescent sample reported that those victimized due to their ethnicity/race were more likely to forego medical care (i.e., not go to the emergency department when needed) and go more than 2 years since their last routine well visit (Galán et al., 2021).

Involvement in Risky or Illegal Behaviours
Four studies reported that youth who are ethnically/racially bullied are more likely to act out aggressively towards others in response to their victimization (Galán et al., 2021;Haines-Saah et al., 2018;Lloyd & Stead, 2001) or engage in serious forms of violence such as gang violence (Varma-Joshi et al., 2004). These findings were confirmed in one Canadian longitudinal study that showed that those ethnically/racially bullied reported more externalizing problems concurrently and one year later regardless of immigration status (McKenney et al., 2006). In contrast, an Italian study found no link between ethnic bullying victimization and perpetration (Caravita et al., 2020). Three studies have also found a relationship between bullying victimization due to ethnic/racial and/or religious differences and alcohol and illicit drug use (Cardoso et al., 2018;Hong et al., 2022;Russell et al., 2012). Those engaged in both ethnic/racial bullying perpetration and victimization also reported higher odds of cigarette, alcohol and marijuana use compared to adolescents who were not involved in this type of bullying (Stone & Carlisle, 2017). However, longitudinal evidence on potential interactions among age, racist bullying victimization and substance use is missing (Stone & Carlisle, 2017). Finally, two studies found that those bullied due to their ethnicity/race, citizenship status and/or religion are more likely to be exposed to other forms of violence (Galán et al., 2021;Rodríguez-Hidalgo et al., 2019).

Discussion
Despite increasing research on racist bullying victimization in the last few decades, there is scarcity of studies reviewing the empirical evidence on factors and outcomes associated with this type of bullying. This lack of systematic synthesis of research findings hinders conclusions about the factors and outcomes most and least associated with racist bullying victimization that is essential knowledge for advancing research and theory development in this field. Consequently, the present review synthesized findings from 73 articles and provided an overview of the evidence on individual, school, family, and community-level factors and outcomes associated with racist bullying victimization. Overall, the current review found that racial/ethnic minority, immigrant and refugee youth are disproportionately targeted, and their victimization is influenced by stereotypes and discrimination operating in multiple contexts (e.g., school, community environments). The review also found that racist bullying victimization is associated with a wide range of negative outcomes including poor mental health, lower academic engagement, and an increased risk of involvement in delinquent behaviours, especially among older pupils.

Individual-Level Factors
At the individual level, racial/ethnic minority, immigrant, or refugee status was the factor most consistently associated with racist bullying victimization. This finding is not surprising given that other types of bias-based bullying are most common among young people with the corresponding sociodemographic characteristic (e.g., LGBTQ youth teased about sexual orientation; Bucchianeri et al., 2016). It is important to note that this increased risk also includes children and young people from groups that may not typically be considered as "minority groups" such as children who had returned from England or who had parents who were English and who were found to be bullied in Irish schools due to their different accent (Devine & Kelly, 2006). Research on peer victimization has also shown that ethnic minority youth who do not fulfil stereotypes about their racial and ethnic groups are more likely to be victimized than youth who fulfil these stereotypes (Peguero & Williams, 2013). Also, in some cases children of the same race may be targeted for belonging to a different ethnic group (Eslea & Mukhtar, 2000).
Other individual characteristics were less studied. There was some indication in the literature that youth who are bilingual and use their home country's language at school or at home are more at risk of being bullied due to their perceived immigration status. These findings confirm other research on linguistic diversity and social inclusion that shows that immigrant youth that use their native language at school are more likely to be seen as "different" and, therefore, less likely to be accepted by native peers and more likely to experience antisocial behaviours (Lee et al., 2021;Sauer & Ajanovic, 2012).
There was also some limited research on intersectionality and multiple minority identities suggesting that ethnic minority youth with additional stigmatized characteristics such as being LGBTQ or having a disability are significantly more at risk of racist bullying victimization, however more research is needed in this area (Das-Munshi et al., 2016;. This finding resonates with empirical findings from the wider literature on bias-based bullying and harassment that finds that youth with marginalized identities experience disproportionally high rates of multiple harassment types (Bucchianeri et al., 2016;Galán et al., 2021).
With regards to gender and age differences, there is a less clear picture as relatively few studies have considered these effects. Most studies that investigated gender differences found males to be more at risk. However, this finding may be explained by the fact that racial/ethnic bullying may be too overt for girls to engage in (Larochette et al., 2010) or it may be related to the measurement of the construct across studies with more overt forms of bullying such as name-calling investigated more widely than relational forms, such as social exclusion (see supplementary material). The review found only one study on age effects on racist bullying victimization, therefore more research is needed in this area.

School, Family, and Community-Level Factors
Overall, there has been less research on school, family, and community-level factors influencing racist bullying victimization compared to individual-level factors. Studying these systems factors is important, as they are likely to influence perceptions of the proximal processes occurring in these environments (Benner & Graham, 2013).
In terms of school-level factors, the more consistent findings across the literature were found in relation to perceived levels of racism and discrimination in schools that appears to be a unique influencing factor in this context. Racist bullying was more commonly reported by ethnic minority youth that felt disrespected and discriminated against in their schools and, as a result, had lost faith that their complaints would be taken seriously (e.g., Bešić et al., 2020;Page, 2020). This finding resonates with the wider literature on racism and inclusion that highlights the importance of creating an inclusive school ethos that welcomes diversity (Hek, 2005;Hymel et al., 2015). Disparaging reactions from teachers may lead youth to either be reluctant to report their victimization (Mthethwa-Sommers & Kisiara, 2015) or accept their victimization as "normal" (Varma-Joshi et al., 2004).
Other school-level factors have been less investigated. There was some indication in the literature that those bullied due to their race, ethnicity and/or religion are more likely to also experience other forms of victimization at school (Arens & Visser, 2020;Felix et al., 2009;Goldweber et al., 2013;Hunter et al., 2010;Mendez et al., 2016;Rodriguez-Hidalgo et al., 2014;Seaton et al., 2013) and to feel unsafe at school (Gower et al., 2015;Russell et al., 2012). It has been reported previously in the literature that some children and young people can be targets of different types of victimization (Finkelhor et al., 2009). Several factors have been found to increase the risk of experiencing multiple types of victimization, ranging from neighborhood and household characteristics (e.g., single headed households, family unemployment), to individual characteristics (e.g., age, smoking or alcohol consumption, being male) (Ellonen & Salmi, 2011;Finkelhor et al., 2011). With regards to family-level factors, research is extremely limited in the context of bullying victimization due to race, ethnicity, citizenship status and/or religion. It is known from previous systematic reviews and meta-analyses that child abuse and neglect is considered a risk factor for bullying victimization (Lereya et al., 2013;Nocentini et al., 2019) so this needs to be investigated also in relation to racist bullying. There is a need to study in more detail how family socialisation processes including how parents respond to their children's victimization relate to racist bullying as some research shows that encouraging youth to fight back or accept their victimization as "normal" is linked to increased risk of repeat victimization (Coffin et al., 2010;Varma-Joshi et al., 2004).
Furthermore, some research, conducted primarily with older samples, suggests that bullying victimization due to race, ethnicity and/or religion is linked to delinquency, tobacco, alcohol, and illicit drug use (Cardoso et al., 2018;McKenney et al., 2006;Stone & Carlisle, 2017). This link has also been reported in the general bullying literature where some research has found that experiencing a strain such as bullying can foster substance abuse and delinquency as a way of coping with the strain (Cullen et al., 2008). More research is needed on how age moderates the relationship between racist bullying victimization and externalizing outcomes such as delinquency, tobacco, alcohol, and illicit drug use.
Finally, the review found consistent support for a positive association between academic engagement and bullying victimization due to race, ethnicity and/or religion. Children and adolescents who are bullied because of their race, ethnicity and/or religion are more likely to show lower academic engagement and performance and be more frequently truant from school across all ages (Baams et al., 2017;Lloyd & Stead, 2001;Russell et al., 2012). Due to the correlational nature of most of these studies, it is not possible to ascertain the temporal order of these variables. However, findings from the wider literature on general bullying suggest that being the target of bullying can function as both antecedent and consequence of poor academic achievement and engagement (Laith & Vaillancourt, 2022).

Limitations of the Included Studies
This systematic review provided an up-to-date review of empirical studies investigating bullying victimization due to race, ethnicity, citizenship status and/or religion. Although research on this issue has increased significantly in the last decade, it remains quite limited compared to the attention that has been devoted to understanding other forms of bullying victimization. Most previous research conducted so far on bullying among ethnic and religious minorities does not investigate the perceived motivation behind the victimization. This is a limitation.
The research that does exist has methodological and theoretical limitations. First, there is a preponderance of crosssectional research designs using questionnaire surveys. For this reason, causal inferences are not possible. Furthermore, in many of these studies, bullying due to perceived racial, ethnic, citizenship and/or religious differences is measured with a single item. Second, there is no single agreed definition of what qualifies as racial/ethnic and religious bullying and how it differs from discrimination, peer harassment and/ or peer victimization due to perceived racial, ethnic, citizenship and/or religious differences. The lack of a universal definitional framework makes it harder to synthesise results. Also, only three studies considered cyberbullying due to race, ethnicity and/or religion. More studies that measure cyberbullying are needed to gain insight into the correlates and outcomes associated with this type of bullying.
Third, in many studies, there is also poor conceptualisation of the term "ethnic/racial minority" and "religious minority". For example, many studies are not clear on whether participants self-identified as ethnic/racial and religious minorities or whether they were categorised as such by the researcher(s) based on official information obtained from the school authorities and/or other sources. In addition, studies do not always provide sufficient information on the power differentials between different racial, ethnic, and religious groups in their country. This is an important dimension of the term "ethnic/racial minority" and "religious minority" that studies need to consider more fully so that it is highlighted that minorities include those with less power and privilege in society.
Furthermore, most research on bullying due to perceived ethnic/racial, citizenship and/or religious differences lacks a theoretical framework. Even when a theoretical framework is used, most commonly social identity theory, it is not always clear how theoretical concepts are measured and analysed. For example, although ethnic identification is a key concept 1 3 in social identity theory, this is rarely measured and studied. Therefore, this review highlights a pressing need for improvements in the theoretical design of research on bullying due to race/ethnicity, citizenship status and/or religion to advance the field.
Finally, there is a need for a more systematic investigation of developmental differences in factors and outcomes associated with racist bullying victimization. Despite many studies using samples varied in age, very few report on age moderator effects and/or include multivariate analyses that take into account age.

Strengths and Limitations of This Review
This systematic review had strengths and limitations. It is the first to synthesize both quantitative and qualitative evidence to create a breadth and depth of understanding of individual, school, family, and community-level factors and outcomes associated with bullying victimization due to race, ethnicity, citizenship status and/or religion. The analysis allowed recognition of the distinct factors that influence this type of bullying victimization and the detrimental impact it has on youth. However, it was not possible to conduct statistical analysis of effect sizes nor was it possible to form hypotheses about potential moderators and mediators due to limited reporting in the included studies. Some literature was excluded such as grey literature, studies not published in English or studies measuring related constructs such as peer victimization, harassment, and discrimination.

Future Research and Practical Implications
This systematic review provides key implications for future research and policy development. The reviewed studies indicate that bullying victimization due to ethnic/racial and/or religious differences is influenced by distinct factors such as stereotypes that are pervasive in many contexts including in schools, families, and communities and, therefore, a different prevention and intervention approach is required that considers these systemic, prejudice-related factors. This unique approach to prevention and intervention needs to draw on an integrated framework of theories from multiple fields such as the social psychology prejudice-related literature and the developmental literature on bullying (Earnshaw et al., 2018).
This integrated theoretical framework could be based on a social-ecological model informed by the latest insights from theories of intergroup relations such as social reasoning developmental models (Palmer et al., 2022;Rutland & Killen, 2015). Bullying is an ecological phenomenon that results from an interplay between structural, contextual, and individual factors (Espelage et al., 2013;Swearer & Espelage, 2004). However, Espelage et al. (2013) argue that very little research has comprehensively evaluated the validity of the social-ecological perspective in relation to bullying. Huang and Cornell (2019) agree that most bullying research has concentrated on individual, family, and school influences, with less emphasis on community and mass media exosystems. However, bias-based bullying is especially vulnerable to exosystemic factors, such as mass media and the community environment and by macro factors, such as cultural norms and beliefs (Hong & Garbarino, 2012;Huang & Cornell, 2019). Therefore, these factors need to be investigated in a more systematic way in future research.
The more immediate school context is also important as research has consistently shown that racial/ethnic and religious bullying is more likely to be experienced in schools with perceived high levels of racism and intolerance. This shows the importance of ensuring that teachers and other school staff receive sufficient education and training on promoting cooperative learning structures (Farmer et al., 2011;Hymel et al., 2015). Cooperative learning environments implicitly communicate civic values to students that in turn influence how groups interact (Johnson & Johnson, 2012). It is also important for teachers to be regularly provided with opportunities to reflect on their practice and how it might be influenced by their own attitudes and beliefs.
Other contextual variables such as school and class ethnic diversity also need to be investigated in more detail as results are less consistent. For example, some research has shown that majority group members can also be victimized when they are a numerical minority in their school or community as the size of the group changes power differentials (Durkin et al., 2012;Schumann et al., 2013). Furthermore, it is not clear if high ethnic diversity in classrooms and schools is a protective or a risk factor (Bayram et al., 2018;Verkuyten & Thijs, 2002). A recent systematic review found that the effect of ethnic diversity on bullying may be culture and age specific (Basilici et al., 2022).
In comparison to general bullying, racial/ethnic and religious bullying is also driven by social-cognitive factors of stigma (e.g., social dominance orientation, stereotypes, and prejudice) and group processes (e.g., intergroup contact, group norms, group identification, and intergroup anxiety) that need to be more systematically integrated and investigated in research (Earnshaw et al., 2018;Priest et al., 2021). Social reasoning developmental models (Killen & Rutland, 2011;Rutland & Killen, 2015) and social identity frameworks (Gini, 2006) provide some useful direction on the type of variables that might be investigated under such an integrated theoretical framework.
According to these theoretical models, intergroup processes (e.g., group norm, group identification, intergroup contact, and intergroup anxiety) influence children and adolescents' behavior in intergroup situations such as racial/ethnic and religious bullying (Abbott & Cameron, 2014;Palmer et al., 2015). For example, social identity development theory suggests that bullying and other kinds of inter-group conflict during childhood are more likely if in-group members think that their standing might be enhanced by outgroup dislike and attack, or if they believe that their status is threatened by members of an out-group (Gini, 2006;Nesdale & Scarlett, 2004). At the same time, intergroup contact has been found to improve intergroup relations and reduce prejudice (Keles et al., 2021;Pettigrew & Tropp, 2006). In addition, Palmer and Abbott (2018) argue that with age, group characteristics (group norms, status, identity) become more important and may overrule moral concerns (e.g., wrongfulness of prejudice). More research studying these factors and their interaction with other individual and systems-level factors is urgently required to advance prevention and intervention efforts in this field.
For example, a factor that requires to be investigated in more detail is strength of ethnic identification as this is a key variable in social identity theory (Tajfel, 1982), however it is not clear if a stronger ethnic identity increases or decreases the risk of racist bullying (Verkuyten, 2002;Verkuyten & Thijs, 2001;Wong et al., 2003). Related to this, there is also a need to investigate further how bullying victimization due to race/ethnicity, citizenship status and/or religion may affect perceptions of one's own social identity and/or how it might enhance cultural mistrust (Benner & Graham, 2013).
This review also found only two studies that investigated the protective factors that buffer against the negative outcomes of racial/ethnic and religious bullying victimization. This research suggests that how victims of racial/ethnic and religious bullying cope with their victimization may influence the magnitude of negative outcomes they experience because of their victimization. For example, some research has shown that helpful coping strategies were filtering out negative reactions, staying indifferent, making a joke about it, and connecting online with existing friends (Banerjee et al., 2020;Mendez et al., 2016). More research is also needed to establish whether bullying victimization due to ethnic/racial and/or religious differences is more damaging than other forms of bullying as some initial research suggests (Russell et al., 2012).

Conclusions
Research on racist bullying victimization has increased in recent years, however, in the absence of a systematic synthesis of the empirical evidence, it is not clear what factors and outcomes are most consistently associated with this type of bullying victimization. This review found that adverse school and community environments that perpetuate negative stereotypes and discrimination put racial/ethnic and religious minorities at increased risk of racist bullying victimization. The review also found that racist bullying victimization is associated with a wide range of negative outcomes including poor mental health, lower academic engagement, and an increased risk of involvement in delinquent behaviours, especially among older pupils. The finding that those bullied due to their race/ethnicity, citizenship and/ or religion perceive to be discriminated and disrespected by their teachers highlights the importance of developing anti-bias, anti-racism, and inclusion training materials for educators, and implementing multi-level interventions that are targeted towards different groups such as teachers and pupils. Better knowledge of how intergroup processes influence racial/ethnic and religious bullying would help create more tailored and effective approaches to prevention and intervention. This unique approach to prevention and intervention needs to draw on an integrated framework of theories from multiple fields such as the social psychology prejudice-related literature and the developmental literature on bullying. This review concludes that more studies on racial/ ethnic and religious bullying are required, especially those that investigate the interaction between individual, systemic and intergroup factors.
Authors' Contributions MS conceived of the study and design, conducted the search, worked on the analysis, and produced the final version of the manuscript. LDA conducted the search and contributed to the study selection, quality appraisal and the manuscript. LV contributed to the study selection and to the manuscript. All authors read and approved the final manuscript.
Data Availability All data generated or analysed during this study are included in this published article (and its supplementary information files).

Conflict of interest The authors report no conflicts of interest.
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