The Family Transmission of Ethnic Prejudice: A Systematic Review of Research Articles with Adolescents

Abstract

Ethnic prejudice is one of the most studied topics in social psychology. Empirical research on its development and intergenerational transmission is increasing but still scarce. This systematic review collected and analyzed psychosocial studies focused on the transmission of ethnic prejudice within families with adolescents. Specifically, it aimed at addressing the following research questions: (a) To what extent is there a vertical (between parents and children) and horizontal (between siblings) transmission of ethnic prejudice within the family? (b) Is this process unidirectional (from parents to children) or bidirectional (between parents and children)? (c) Which individual and/or relational variables influence this process? (d) Can adolescents’ intergroup contact experiences affect the family influence on adolescents’ ethnic prejudice? The literature search of four databases (Ebsco, Scopus, PubMed, and Web of Science), carried out from February 2021 to May 2021, following the PRISMA guidelines, yielded 22 articles that matched the eligibility criteria. The findings highlighted a moderate bidirectional transmission of ethnic prejudice between parents and adolescents, which was influenced by several individual and relational variables (e.g., the adolescents’ age and sex and the family relationship quality). Moreover, the adolescents’ frequent and positive contacts with peers of different ethnicities reduced the parents’ influence on the adolescents’ ethnic prejudice. The findings are discussed, and their limitations and implications for intervention and future research are considered.

1. Introduction

No child is born with prejudice (…)

The context of his/her learning is always

the structure where his/her personality develops.

(Allport 1954)

Ethnic prejudice is one of the most challenging and discussed topics in the field of social psychology and public debate; this has been generated in large part by the increasing immigration and refugee flows. In his pioneering work, The Nature of Prejudice, Allport (1954) defined ethnic prejudice as “(…) an antipathy based upon a faulty and generalization. It may be felt or expressed. It may be directed toward a group as a whole, or toward an individual because he is a member of that group” (Allport 1954, p. 9). In its broad sense, it refers to the hostility towards those who are perceived as culturally different (because of their race, immigration background, belonging to ethnic minorities, etc.). Prejudice includes persistent social attitudes, beliefs, emotions, and behaviors that disqualify the members of other social groups (i.e., the outgroup) because of their group belongingness (Brown 1995). It acquires strong socio-cultural roots by being shared among the members of the same social group (i.e., the ingroup) and directed towards the outgroup members (Allport 1954; Dovidio 2001; Pettigrew and Meertens 1995). Prejudice is indeed largely learned and constitutes one of the main “objects” of the socialization process. In the present systematic review, we intended to deepen the role of family, which is one of the main socialization systems, in the transmission of ethnic prejudice to adolescents.

1.1. Prejudice and Ethnicity

Over the years, the expression of prejudice has gradually become less clear and manifest. The phenomenon has become more subtle because it is now considered socially undesirable if openly demonstrated. Nowadays, ethnic prejudice is often conveyed subtly by referring to reasons of a cultural nature, such as nationality, customs, and history (i.e., ethnicity); it differs from the earlier form of racial prejudice that was explicitly expressed and was mainly based on genetic motivations (i.e., race) (Billig 1989; Pettigrew and Meertens 1995).

The two terms—race and ethnicity—are often used interchangeably in literature and empirical research. However, the two aspects have their own specificity: race is a concept that refers to skin pigmentation or physical conformation (Omi and Winant 1994; Jablonski 2021). In contrast, the concept of ethnicity is broader than race and also refers to the history, culture, values, religion, and/or language of a specific population. Based on this, Pettigrew and Meertens (1995) distinguished between blatant and subtle ethnic prejudice. Blatant prejudice refers to the traditional prejudice, which is “warm, close and direct” (Pettigrew and Meertens 1995, p. 58), in which the outgroup members are perceived as threatening, with the consequence that any relationship with them is rejected. Subtle prejudice, described instead as “cold, distant and indirect” (Pettigrew and Meertens 1995, p. 59), is expressed in a covert manner through normative and acceptable ways (e.g., minorities needing to try “hard enough” and to teach their children traditional values).

Despite race and ethnicity being distinct concepts, they are, however, strongly connected (Markus and Moya 2010). Both of them are social constructs used to categorize and characterize groups and are often used to describe immigrant groups and ethnic minorities. Markus (2008) highlighted that they should be productively considered together as a set of dynamic ideas and practices through which people distinguish groups and recognize their specificities in their own communities.

In the psychological literature, two general theoretical approaches regarding the causes of prejudice can be identified: the first emphasizes the cognitive processes and the second the motivational ones (e.g., Rutland et al. 2007; Smetana et al. 2014; Voci and Pagotto 2010). However, they are interdependent and jointly help to better explain the emergence of prejudice. The cognitive approach explains the way human beings perceive social groups based on elementary processes of perception, processing, and coding of information. The incoming information about the outgroup may be voluntarily distorted to make one’s expectations and negative representations of the outgroup consistent. As for the motivational basis of prejudice, the perception is of an exaggerated psychological distance between oneself (and one’s group membership) and others: the outgroup is felt to be threatening and excessively different from one’s own group (i.e., the ingroup). These cognitive and motivational mechanisms are mainly learned and reinforced within the social context. The family plays a significant role in the ability of youths to navigate social situations (Umaña-Taylor and Hill 2020), and it is the privileged environment for transmitting and acquiring beliefs, values, attitudes, and norms that reflect on and are reflected by the wider social context (e.g., Knafo and Assor 2007; Ranieri and Barni 2012).

1.2. Intergenerational Transmission of Ethnic Prejudice

Research on the intergenerational transmission of ethnic prejudice is still scarce, while there are more studies on the transmission of other “objects”, such as, for example, values (e.g., Barni et al. 2011), attachment styles (e.g., Sette et al. 2015), poverty (e.g., Bird 2013), and violence (e.g., Widom and Wilson 2015). These studies are consistent in reporting a significant parent–child transmission (usually measured in terms of similarity or association between the parent and the child), although it is of different strength depending on the construct analyzed as well as on the individual (e.g., personality, birth order, etc.) and family (e.g., relationship quality, parenting style, etc.) characteristics (Barni et al. 2013, 2014). Of course, within the family, the parent–child relationship (i.e., vertical transmission; Berry et al. 2002) is not the only one involved in the transmission process. Sibling relationships (i.e., horizontal transmission; Berry et al. 2002), although less investigated than the parent–child one, could significantly contribute to children’s acquisition of values, beliefs, norms, etc. (Alfieri and Marta 2015).

The first socialization theories conceptualized parent–child transmission as a unidirectional and deterministic process in which parents are active agents while children are a sort of “blank slate” to be written on by parental interventions and intentions (Barni et al. 2013; Maccoby 2003). In contrast, the current socialization theories are consistent in describing the transmission as a bidirectional and dialectical process in which both the parents and the children are active and able to influence the outcomes (Kuczynski et al. 1997; Kuczynski and Navara 2006). Schönpflug and Bilz (2009), in their well-known Filter Model, pointed out that the transmission is a negotiation process within the family which is regulated by an interactive contribution of the parents and the children. When considering value transmission, Grusec and Goodnow (1994) suggested that children do not imitate parental values, but rather, they interpret these values in unique and innovative ways. According to Grusec and Goodnow’s (1994) Two-Step Model of Values Acquisition, the offspring’s perceptual accuracy regarding, and acceptance of, the values their parents want to convey to them (called socialization values; Barni et al. 2017) are the pre-conditions for achieving a high value similarity between the two generations.

Children become particularly active in the transmission process from their adolescence (Albert and Ferring 2012). This is largely due to the significant personal and social identity changes that occur during this phase of the life cycle (Knafo and Schwartz 2004). Among the many changes, adolescents become able to think about themselves, as well as about others, and consider multiple, diverse, and non-overlapping categories (Crocetti et al. 2021). During adolescence, parents and adolescents are called upon to renegotiate the asymmetrical authority of earlier periods (Grotevant and Cooper 1985), and adolescents become more and more involved in social relationships outside the family (Dhont and Van Hiel 2012).

Studies concerning the transmission of ethnic prejudice have unfortunately focused almost exclusively on childhood, thus leaving the adolescence phase under-investigated (Crocetti et al. 2021). Around the age of seven to eight, children begin to consolidate a preference for their ethnicity and progressively reach an identification with their ethnic ingroup. The research involving parents and pre-school- and school-age children (up to 12 years) showed mixed results. Indeed, some of them found a high degree of similarity between the parents’ and the children’s ethnic prejudice (e.g., Epstein and Komorita 1966; Katz 2003), while others reported only a moderate or low similarity (e.g., Mosher and Scodel 1960; Davey 1983; Aboud and Doyle 1996; O’Bryan et al. 2004). Castelli et al. (2009), in their study involving Italian parents and biological three- to six-year-old children, found that the parents’ explicit and implicit negative attitudes1 towards immigrants predicted those of their children, but only in the case of the mothers. The authors explained these findings by referring to the fact that in Italy mothers are usually the primary caregiver and spend more time with their children than fathers. As such, mothers would have more chances to influence the socialization of their children’s attitudes towards immigrants through daily activities (Castelli et al. 2009). Interestingly, these results seem to suggest a specific, not interchangeable, role of the father and the mother in the children’s acquisition of ethnic prejudice.

Allport (1954) claimed that the development of prejudice is based on three factors: direct interpersonal learning, conformity, and contact. Learning and conformity primarily depend on the family. The first implies that parents express their point of view explicitly with respect to outgroups, as in, for example, “the inhabitants of X are unpleasant”. Children associate the label of this group with an emotion (dislike); in the years to come, this emotion will likely be associated with the label and generalized to the entire group. Complying with this kind of parental learning means that children become aware of the norms of the family. Children desire to identify with the group to which they belong (e.g., their family), and they need group approval (e.g., parental approval). Thus, they tend to conform to the family’s norms that they learn. Differently, intergroup contact refers to the experiences outside the family (e.g., in the school setting, in relationships with peers, etc.). Families are embedded in multiple and changeable contexts that reflect community structure and processes (Scabini and Cigoli 2000). Though families influence those contexts to some degree, they are mainly recipients of events, traditions, norms, values, and attitudes that comprise community collective life (Mancini and Bowen 2013). When positive intergroup contacts occur under some conditions (i.e., equal status, common goals, cooperation, and support by authorities), they can reduce prejudice by promoting tolerance and mutual acceptance.

1.3. The Present Study

In the light of the above, and in consideration of the relevant and complex role of the family as a socialization system strongly embedded in a larger social context, this systematic review aims at collecting and analyzing the studies concerning the transmission of ethnic prejudice within families with adolescents. Four main research questions are to be addressed:

(a) To what extent is there a vertical (between parents and children) and horizontal (between siblings) transmission of ethnic prejudice within the family? Regarding this first research question, given the prominent contribution of parents to the transmission processes and considering the literature regarding the other “objects” of socialization (e.g., values; Barni et al. 2014; Knafo and Schwartz 2003), which mainly aims to study parent–child similarities, we expected to find more studies concerning vertical transmission than the horizontal one (H1a), highlighting, overall, a similar strength of vertical and horizontal transmission (H1b). Both parent–child and sibling relationships are indeed central in adolescents’ life, and the family relationship quality helps in predicting a variety of adolescent outcomes (e.g., social attitudes and competences, health, and delinquency; see, Senguttuvan et al. 2014). Although siblings have less “authority” than parents in family relations, they grow up together, often belonging to the same cohort and living the same phase of the life cycle (e.g., adolescence).

(b) Is the family transmission of ethnic prejudice unidirectional (from parents to children) or bidirectional (between parents and children)? The role of children has for a long time been considered passive in the family transmission processes (e.g., Barni et al. 2013; De Mol et al. 2013; Maccoby 2003); we therefore expected most studies to analyze the unidirectional transmission from parents to children, without explicitly dealing with the nature (unidirectional or bidirectional) of the transmission (H2a). This is also because the study of bidirectionality needs complex research designs, including longitudinal data collection and sophisticated data analysis. Based on the more recent debate on the topic, clearly supporting parent–child bidirectional effects especially from adolescence (e.g., Kuczynski and Parkin 2007), we expected to confirm the bidirectionality through empirical evidence (H2b).

(c) Which individual and/or relational variables influence the transmission of ethnic prejudice within the family? We expected to identify several individual (e.g., sex and age) and relational variables (e.g., parenting style and relationship quality) able to influence the transmission of ethnic prejudice (H3). As interestingly suggested by Schönpflug (2001), transmission may be enhanced by “transmission belts”, that is, conditions favorable for transmission in a particular socio-cultural context, such as the individual characteristics of the “transmitter” and the “receiver” and the family interaction and relationship variables.

(d) Can adolescents’ intergroup contact experiences affect the family influence on adolescents’ ethnic prejudice? To be consistent with Allport’s hypothesis (1954) and its recent extensions, we hypothesized that frequent and positive intergroup contacts should help in reducing adolescents’ ethnic prejudice and in mitigating the influence of parents’ prejudice on adolescents (H4).

We decided to focus on adolescence (from early to late adolescence) because, as suggested by the analysis carried out by Raabe and Beelmann (2011), ethnic prejudice tends to become more context-dependent within the course of development from childhood towards adolescence. Thus, adolescence may be an extremely sensitive period with regard to the family reinforcement of negative ethnic attitudes and discriminatory behaviors. Moreover, as already mentioned in the introduction, adolescence could be considered a critical developmental period because it is characterized by several personal, psychological, and even social changes (Russo et al. 2022). As is known, adolescence marks the beginning of the development of more complex thinking processes, with personal and social identity formation being probably the main task of this life period. Adolescents are increasingly engaged in multiple social contexts (e.g., family, school, peer groups), where they constantly negotiate attitudes, beliefs, values, and behaviors in the attempt to understand who they are and who they want to be (see, for example, Crocetti et al. 2021; Váradi et al. 2021). This also happens with reference to prejudicial attitudes (e.g., Hjerm et al. 2018). The social-cognitive developmental theory of prejudice highlighted that the cognitive changes beginning from adolescence “bear directly on the young person’s view of self and others, and therefore on prejudice” (Aboud 2008, p. 55). Identity development, learning, conformity, and intergroup experiences, which are traditionally considered the principal mechanisms in shaping the nature and extent of prejudices (Aboud 2005), are relevant processes in adolescence. All this makes the exploration of this life phase particularly interesting. Reference is also made to the role of family and intergroup experiences in the transmission and internalization of ethnic prejudice.

2. Materials and Methods

2.1. Protocol and Registration

The present systematic review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) (see in Supplementary Materials) statement 2020 (Page et al. 2021).

2.2. Data Source and Search Strategy

We searched for studies through the Ebsco databases (APA PsycInfo, SocINDEX with Full Text, Psychology & Behavioral Sciences Collection), Scopus, PubMed, and Web of Science (Article title, Abstract, Keywords). We conducted the literature search in the selected databases from February to May 2021 without imposing any date restriction with regard to the publications.

We used an interactive search strategy with the combination of the following keywords in English, Italian, or Romanian, based on the linguistic competences of the authors: (“ethnic prejudice” or “racial prejudice” or “attitudes towards immigrants” or “anti-immigrant attitudes”) AND (“transmission” or “socialization”) AND (“parents” or “siblings” or “family” or “parent-child relationship” or “family relationship”) AND (“adolescence” or “adolescent” or “teenage” or “teenager”).

2.3. Inclusion Criteria

The following inclusion criteria for studies to be incorporated in the review were adopted: research studies were needed that (1) analyzed the family transmission of ethnic prejudice; (2) were family research and involved at least one parent and one adolescent child or two or more siblings; (3) were peer-reviewed studies, with a longitudinal or a cross-sectional research design; and (4) were written in English, Italian or Romanian, to provide an additional comparative perspective. As suggested by Walpole (2019), we included all the languages we know in order to obtain as complete a picture as possible on the family transmission of ethnic prejudice in adolescence2.

2.4. Quality Assessment

For the quality assessment, we used the appraisal tool (AXIS) for observational and cross-sectional studies (Downes et al. 2016). It is composed of a checklist of 20 items, which evaluate the overall study design and the risk of bias. An item example is: “Were the aims/objectives of the study clear?”. The items were scored as follows: Yes = 1, No and Don’t know = 0; this resulted in a final score that ranged from 0 to 20, with higher scores indicating a higher assessed quality. Adopting the classification used in other literature reviews (e.g., Moor and Anderson 2019; Musetti et al. 2022), three quality levels were distinguished: low quality (0–7 points), moderate quality (8–14 points), and high quality (15–20 points). For the longitudinal studies, in line with the previous reviews (e.g., Lannoy et al. 2021), we took only the first wave into account for answering the AXIS items.

3. Results

3.1. Study Selection and Data Extraction

The search of the studies to include in the review produced 687 results on the Ebsco databases; Scopus yielded 919, PubMed 128, and Web of Science 23. Based on the reading of the titles and abstracts, 624 records were removed from Ebsco, 768 from Scopus, 109 from PubMed, and 6 from Web of Science. These articles did not cover the topic we were interested in, but focused on topics such as the transmission of diseases, illness, etc. As shown in Figure 1, a total of 250 records were retained (Ebsco 63; Scopus 151; PubMed 19; Web of Science 17). After the screening of the papers for title and abstract, we removed duplicates (N = 161). We then proceeded with full-text screening if the abstract did not present enough information to determine inclusion. In doing so, we discovered that 19 articles were not suitable for the review based on the inclusion criteria. From 89 records, after removing duplicates, 70 were obtained for the full text. From these 70 records, 48 articles were excluded for the following reasons:

Reason 1: 18 studies were excluded because the age of the children was out of the range of interest (i.e., adolescence);

Reason 2: 18 studies were excluded because they were not pertinent to the process of the transmission of ethnic prejudice within the family;

Reason 3: two studies were excluded because they analyzed adolescents’ ethnic prejudice but did not involve either parents or siblings;

Reason 4: 10 studies were reviews, meta-analyses or book chapters, and they were excluded because they did not satisfy our inclusion criteria. Considering book chapters, we chose not to include them because we could not be sure they had been subject to a peer review process. Eventually, 22 papers met the inclusion criteria and were included in the systematic review (Figure 1).

3.2. Main Characteristics of the Included Studies

Table 1. Characteristics of the studies included in the systematic review.

Authors, Year of Publication	Country	Focus of the Study	Research Design and Instruments	Participants	Vertical or Horizontal Transmission	Testing Bidirectionality Transmission Yes/No
Alfieri and Marta (2015)	Italy	Sibling relationship’s role in the socialization of ethnic prejudice	Cross-sectional; Self-report questionnaires	88 sibling dyads	Horizontal	No
Carlson and Iovini (1985)	USA	Relationship between racial attitudes of fathers and sons	Cross-sectional; Self-report questionnaires	200 dyads (father–son)	Vertical	No
Dhont and Van Hiel (2012)	Belgium	Role of intergroup contact in the intergenerational transmission of racial prejudice	Cross-sectional; Self-report questionnaires	99 dyads (one parent and one adolescent)	Vertical	No
Dhont et al. (2013)	Belgium	Similarity between parents’ and children’s anti-immigrant prejudice	Cross-sectional; Self-report questionnaires	169 dyads (one parent and one adolescent)	Vertical	No
Duriez (2011)	Belgium	Role of parental figure in adolescent ethnic prejudice	Cross-sectional; Self-report questionnaires	240 mother–child dyads and 210 father–child dyads	Vertical	No
Duriez and Soenens (2009)	Belgium	Intergenerational transmission of racism	Cross-sectional; Self-report questionnaires	528 mother–child dyads and 447 father–child dyads	Vertical	No
Duriez et al. (2008)	Belgium	Intergenerational transmission of authoritarian submission and authoritarian dominance as predictor of prejudice	Cross-sectional; Self-report questionnaire	536 mother-child dyads and 472 father–child dyads	Vertical	No
Eckstein et al. (2018)	Germany	Siblings’ influence on intergroup attitudes	Longitudinal (2 waves); Self-report questionnaires	117 sibling dyads	Horizontal	No
Rodríguez-García and Wagner (2009)	Costa Rica	Models of transmission between parent–adolescent attitudes towards immigrants	Cross-sectional; Self-report questionnaires	408 dyads (one parent and one adolescent)	Vertical	No
Gniewosz and Noack (2015)	Germany	Parent–adolescent transmission of attitudes towards immigrants	Longitudinal (5 waves) and 3 cohorts; Self-report questionnaires	339 mother–son dyads; 433 mother–daughter dyads; 292 father–son dyads; 362 father–daughter dyads	Vertical	No
Hello et al. (2004)	The Netherlands	Effects of educational attainment compared to parental influence on ethnic prejudice of mid/late adolescents	Longitudinal (2 waves); Self-report questionnaires	T1: 484 triads with mother, father, and one adolescent; T2: 301 triads with mother, father, and one adolescent	Vertical	No
Jaspers et al. (2008)	The Netherlands	Parent–child similarities with respect to attitudes towards ethnic minorities	Cross-sectional; Self-report questionnaires	367 triads with mother, father, and adolescent	Vertical	No
Jugert et al. (2016)	Germany	Influence of parents’ ethnic intergroup attitudes on the development of their children’s ethnic intergroup attitudes	Longitudinal (5 waves); Self-report questionnaires	184 mothers, 158 fathers, and 188 adolescents	Vertical	No
Kulik (2004)	Israel	Birth order and its impact on intergenerational transmission of parental attitudes towards immigrants	Cross-sectional; Self-report questionnaires	294 families with mother, father, and two siblings	Vertical	No
McHale et al. (2007)	USA	Sibling relationships and family characteristic regarding racial socialization	Cross-sectional; Self-report questionnaires and interviews	172 families with mother, father, and two siblings	Horizontal	No
Meeusen (2014)	Belgium	Parental role in the anti-immigrant prejudice of their children	Cross-sectional; Self-report questionnaires	1708 triads with mother, father, and adolescent	Vertical	No
Meeusen and Dhont (2015)	Belgium	Parent–child similarity in different types of prejudice, including ethnic prejudice	Cross-sectional; Self-report questionnaires	1530 triads with mother, father, and adolescent	Vertical	No
Miklikowska (2016)	Sweden	Influence of parents’ prejudice and tolerance towards immigrants on adolescents’ attitudes and vice versa (from adolescents to parents)	Longitudinal (2 waves); Self-report questionnaires	507 triads with mother, father, and adolescent	Vertical	Yes
Miklikowska (2017)	Sweden	The effects of parents on adolescents’ anti-immigrant attitudes	Longitudinal (3 waves); Self-report questionnaires	517 triads with mother, father, and adolescent	Vertical	No
Miklikowska et al. (2019)	Sweden	The effects of parents’ attitudes on changes in youth anti-immigrant attitudes	Longitudinal (3 waves); Self-report questionnaires	T1: 438 triads (mother, father, adolescent), T2: 330 triads (mother, father, adolescent), T3: 246 triads (mother, father, adolescent)	Vertical	No
O’Bryan et al. (2004)	USA	The intergenerational transmission of prejudice and stereotyping	Cross-sectional; Self-report questionnaires	111 triads with mother, father, and adolescent	Vertical	No
White and Gleitzman (2006)	Australia	The association of parents’ racial attitudes with adolescents’ racial attitudes	Cross-sectional; Self-report questionnaires	Family triads with 86 mothers, 75 fathers, and 93 adolescents	Vertical	No

Note. In the Table, we reported the prevalent term (ethnic prejudice, racial attitudes, racial prejudice, etc.) used by the authors in their studies for greater adherence to the original works.

synthesizes some relevant information about the 22 studies included in the systematic review (i.e., authors, year of publication, country, focus of the study, research design, instruments, participants, and type of transmission). Regarding the period of publication, the articles were published in a timeframe of 34 years. The earliest was in 1985 (Carlson and Iovini 1985) and the most recent was in 2019 (Miklikowska et al. 2019). With regard to the country where the studies were carried out, they were distributed as follows: Belgium (N = 7), Sweden (N = 3), Germany (N = 3), USA (N = 3), the Netherlands (N = 2), Costa Rica (N = 1), Australia (N = 1), Italy (N = 1), and Israel (N = 1).

In terms of research design, most of the studies adopted a cross-sectional design (N = 15), while the remaining seven studies used a longitudinal design. All the studies had a quantitative approach and used self-reporting measures (i.e., questionnaires). Only McHale et al. (2007), in their mixed-method study, used questionnaires together with interviews, with the aim of exploring parents’ knowledge of their offspring’s daily activities and experiences.

The 22 studies were heterogeneous in terms of participants and unit of analysis. In this regard, the studies can be divided into three main categories: the studies which involved four family members (i.e., both parents and two adolescents; N = 5); those with family triads (i.e., both parents and one adolescent; N = 9); and those involving family dyads (e.g., one parent and one adolescent or two siblings; N = 8). Considering the age range of the adolescents involved in the studies, the lowest mean age was 13.41 years (Miklikowska 2016), and the highest was 19.25 years (White and Gleitzman 2006). Nonetheless, six studies did not report the mean age of the sample (Carlson and Iovini 1985; Gniewosz and Noack 2015; Hello et al. 2004; Jaspers et al. 2008; Jugert et al. 2016; O’Bryan et al. 2004), but it was specified that the participants were adolescents.

Interestingly, 20 studies out of the 22 included in this review excluded participants with an immigrant background. Only two studies (Miklikowska et al. 2019; White and Gleitzman 2006) included participants with an ethnic/immigrant background (at least one parent born outside the countries where the study was carried out). In their study, Miklikowska et al. (2019) also involved adolescents from Sweden and those with at least one parent born outside the Nordic countries or outside of Europe. The study of White and Gleitzman (2006), conducted in Australia, had Anglo-Australian, European, and Asian students as participants.

3.3. Emerging Themes

We clustered the studies based on the emerging themes (i.e., vertical vs. horizontal transmission, unidirectional vs. bidirectional transmission, individual vs. relational variables, and intergroup contact). Figure 2 reports the themes and their codes.

3.3.1. Vertical and Horizontal Transmission

Overall, the selected studies showed a significant family transmission process of ethnic prejudice. Specifically, in line with our first hypothesis (H1a), 19 studies (86.4% of the total) focused on the vertical transmission, i.e., between parents and adolescents, and 3 (13.6%) considered the horizontal one, i.e., between siblings (see Table 1). This implicitly suggests that parents, more than siblings, are considered to be the most influential source regarding ethnic prejudice within the family. None of the studies has jointly analyzed vertical and horizontal transmission.

Concerning the strength of the transmission process (H1b), most studies on vertical transmission reported a heterogeneous strength, from low to large (Cohen 1988). Indeed, the effect of parent–child transmission varies from low (Carlson and Iovini 1985; Duriez and Soenens 2009; Hello et al. 2004; Miklikowska 2016) to moderate (Dhont et al. 2013; Meeusen 2014; Miklikowska 2017; Miklikowska et al. 2019) to quite large (Dhont and Van Hiel 2012; Jaspers et al. 2008).

Both parents seem to contribute to their adolescents’ prejudice in similar quantitative terms (e.g., Rodríguez-García and Wagner 2009; Miklikowska 2017; Miklikowska et al. 2019). However, notably, O’Bryan et al. (2004) reported that the mothers’ and fathers’ roles in the transmission to adolescents depend on the target of prejudice, with mothers more influential on their children’s ethnic prejudice than fathers.

Several complex parent–child transmission mechanisms were highlighted. Duriez and Soenens (2009) concluded that the intergenerational transmission of racism is supported by a more fundamental transmission process of ideology. More specifically, in a sample of adolescents and their parents living in the Flemish-speaking part of Belgium, the authors found that intergenerational similarity in right-wing authoritarianism (RWA) and social dominance orientation (SDO) largely accounts for intergenerational similarity in racism. The degree to which adolescents subscribe to the prejudice dimensions of RWA and SDO is positively related to parental promotion of extrinsic goals (i.e., outward orientation aimed at making a good impression through acquiring external indicators of worth, such as financial success and social recognition) at the expense of intrinsic goals (i.e., inward orientation aimed at realizing basic growth tendencies, such as self-development, building satisfying relations, and helping people). Duriez (2011) found that parental extrinsic-goal promotion stimulates adolescents to pursue extrinsic over intrinsic goals, which, in turn, leads them to adopt RWA and SDO, which then predict ethnic prejudice.

Less is known about the horizontal transmission of ethnic prejudice within the family and its mechanisms. As previously mentioned, only three studies (Alfieri and Marta 2015; Eckstein et al. 2018; McHale et al. 2007) analyzed the transmission between siblings. Overall, based on the size of the relation found between siblings’ ethnic prejudice, it is possible to state that there is a moderate (Eckstein et al. 2018; McHale et al. 2007) or large (Alfieri and Marta 2015) amount of transmission between younger and older siblings. The only longitudinal study focused on the sibling effects on youth intolerance towards immigrants (Eckstein et al. 2018), drawing on a sample of German sibling dyads, showed that younger siblings’ attitudes were predicted by those of older siblings, and that younger sisters were more susceptible than younger brothers. In Alfieri and Marta’s (2015) cross-sectional study, conducted on a sample of Italian sibling dyads, it was shown that both the older sibling’s and the younger sibling’s ethnic prejudices decreased in a case of indirect contact; that is, when the sibling had a friend with different origins, specifically an African friend that lived in Italy. Furthermore, McHale et al. (2007) found that a positive relationship between siblings promotes a greater ethnic identity (considering sibling relationships in two-parent African-American families). Interestingly, these findings remained the same when the parental intergroup attitudes were controlled, thus suggesting that siblings can be a relevant and specific source of ethnic prejudice for adolescents, even when acting independently of their parents’ influences.

3.3.2. Unidirectional and Bidirectional Transmission

In line with our second hypothesis (H2a), although the more recent theories of socialization invite the adoption a bidirectional and dialectical perspective in studying transmission (e.g., De Mol et al. 2013; Kuczynski and Parkin 2007)—which assumes that parents influence their offspring’s attitudes and are simultaneously influenced by them—only a few studies (i.e., Rodríguez-García and Wagner 2009; Miklikowska 2016) have empirically tested the unidirectional vs. bidirectional nature of the parent–child transmission of ethnic prejudice.

Concerning the bidirectionality of ethnic prejudice transmission (H2b), the findings were inconsistent. In their cross-sectional research carried out on 408 parent–adolescent dyads from the ethnic majority population in Costa Rica, Rodríguez-García and Wagner (2009) compared unidirectional and bidirectional models of prejudice transmission through non-recursive structural equation modelling. The results supported the unidirectional model of prejudice transmission from parents to offspring, even if the moderating effects of sex, age, and importance of contact were taken into account. However, in their conclusions, the authors stressed the need for future research to be conducted in different countries and based on longitudinal data as this would be an opportunity to test causal relations. Costa Rica is characterized by a collectivistic culture, where children are expected to conform to ingroup authorities such as parents. Thus, it cannot be excluded that in more individualistic cultures, children’s influence on their parents’ ethnic prejudice might be stronger. This seems to be suggested by Miklikowska’s (2016) findings; analyzing longitudinal data (two waves) and focusing on Swedish families, the author showed a mutual effect between parents and adolescents in transmitting prejudice and tolerance towards immigrants. Interestingly, these mutual effects were of equal magnitude. The results also suggested that parents’ prejudice influenced adolescents’ attitudes to the extent that the offspring perceived their parents as supportive.

3.3.3. Individual and Relational Variables Affecting Transmission

In line with our third hypothesis (H3), the analyzed studies pointed out that several variables, both individual and relational, are linked to or influence the parent–child transmission of ethnic prejudice and its outcomes (i.e., the strength of association between parents’ and adolescents’ prejudice or parent–child prejudice similarity).

Regarding individual variables (i.e., parents’ and adolescents’ sex, adolescents’ age and birth order, and parents’ education), two studies reported that children acquire prejudice and negative attitudes towards immigrants more from the same-sex parent rather than from the opposite-sex one (O’Bryan et al. 2004; Rodríguez-García and Wagner 2009). Additionally, O’Bryan et al. (2004) showed that mothers are in general more influential on their children’s racial prejudice. Specifically, it emerged that mothers affect their daughters’ but not their sons’ prejudices, while fathers have a primary role in the transmission of prejudice regarding female stereotyping. Duriez and Soenens (2009) reported a different result: the father–child concordance on racism was not significantly stronger than the mother–child concordance. The results with regard to the adolescents’ sex are instead inconsistent. While in the study of Jugert et al. (2016), girls showed less intergroup prejudice than boys, Jaspers et al. (2008) showed instead no difference in attitudes towards ethnic minorities based on the adolescents’ or the parents’ sex.

As far as the age of the adolescents was concerned, Gniewosz and Noack (2015) found that offspring are particularly susceptible to parental influence about attitudes towards immigrants during early adolescence (between grades 6 and 7) and that the effect of the parents’ attitudes persists until the age of 16. Similarly, Miklikowska (2016) showed that parental prejudice predicts a change in ethnic attitudes from the beginning to the end of adolescence. Miklikowska (2016) also highlighted that the long-term effect of parental ethnic prejudice was more stable than that from peers, probably because the relationship with parents is more lasting compared to the ones with peers in transitional periods, such as adolescence.

Adolescents’ birth order was considered in relation to the strength of ethnic prejudice transmission only in one study, the one by Kulik (2004). The author found the highest correlation between the attitudes towards ethnic stereotypes of the father and those of the firstborn child, with the middle and youngest children following in this order. The correlation between mother and child went exactly in the opposite direction, with the attitudes of mothers being more closely related to those of the youngest child.

Hello et al. (2004) examined the impact of the education attainment of the family members. The fathers’ and the mothers’ social positions turned out to affect their children’s educational attainment (although in different ways), which in turn decreased their level of ethnic distance. Moreover, this study highlighted that education is the most important socializing agent for preventing young adults from avoiding social contact with ethnic minorities and, most likely, for transmitting tolerant or liberal values. Duriez and Soenens (2009) indicated that boys, compared to girls, and technical students, compared to arts and academic-track students, scored higher on racism. In addition, in their study, the educational level of both parents was significantly related to racism. Similarly, Miklikowska (2017) showed that parental income and education predicted changes in adolescents’ anti-immigrant attitudes. Adolescents with poorer parents increased in prejudice more than adolescents with wealthier parents. Regarding education, only adolescents with better-educated parents showed a decrease in the level of prejudice over time. In line with the findings of Miklikowska (2017), Jugert et al. (2016) pointed out that families with a high SES (socio-economic status) seem to provide a context that facilitates positive ethnic intergroup relations.

Regarding the relational variables, the most frequently investigated ones were related to parent–child relationship quality, parenting styles, and family closeness. In this regard, Miklikowska’s (2016, 2017) studies analyzed the relation between the parent–child relationship quality and the strength of the intergenerational transmission of prejudice. The results highlighted that intergenerational transmission is moderated by relationship quality, that is, the better the relationship, the stronger the parental influence. Carlson and Iovini (1985) found that parent–child relationships, particularly the one between the father and the adolescent, have a relevant impact on racial attitudes. Jaspers et al. (2008) stated that the prejudice transmission from parents to adolescents depends on the family relationship quality and family closeness.

As far as parenting styles were concerned, Jugert et al. (2016) showed that children with highly controlling mothers had a tendency to increase the ingroup bias over time, while the pattern was reversed among children with high SDO but low-controlling mothers. Duriez’s (2011) results pointed out that authoritarian parenting, based on promoting extrinsic goals and stimulating competition, promotes ethnic prejudice among adolescents and increases aggressive attitudes towards immigrants. Authoritarian parenting not only elicits ethnic prejudice in children regardless of the level of parental prejudice, but also facilitates intergenerational transmission from parents to children. Being authoritarian conveys values such as conformity and self-promotion to children (Duriez et al. 2008) and leads to children’s authoritarianism and prejudice against immigrants (Rodríguez-García and Wagner 2009). Discussing political and social issues with children helps in increasing parent–child similarity in attitudes towards immigrants (Meeusen and Dhont 2015). Duriez (2011) also claimed that the more similar parents and offspring are in terms of ethnic prejudice, the more likely an intergenerational transmission of ideology is to occur.

3.3.4. Intergroup Contact

The role of intergroup contact and friendship in the intergenerational transmission of ethnic prejudice within the family is a further important theme that emerged from the analysis of the studies. Rodríguez-García and Wagner (2009) highlighted the possible effect of intergroup contact as a moderator in the transmission process. The association between parent–child prejudices was found to be stronger in dyads whose members both gave little importance to the intergroup contact than in dyads where the adolescent gave high importance to having intergroup contact. Moreover, Dhont and Van Hiel (2012) revealed that contacts with peers of different ethnicities lead to a reduction in the transmission of ethnic prejudice. Intergroup contact moderates the relationship between parental authoritarianism and adolescents’ racial prejudice; the relationship was stronger for adolescents with low levels of intergroup contact than for those with high levels of contact. In other words, intergroup contact functions as a buffer mechanism between the parents’ authoritarianism and the adolescents’ racial prejudice.

In her longitudinal study, Miklikowska (2017) pointed out that for early adolescents only, intergroup friendships moderated the effects of parents and peers. For youths with no immigrant friends, parents’ and peers’ prejudice predicted changes in the adolescents’ attitudes, but this did not happen for adolescents with immigrant friends. Despite these results, the adolescents’ intergroup friendships were not related to the parents’ prejudice. Similarly, it has been shown in Meeusen’s (2014) study that there is no relation between parental prejudice and adolescents’ intergroup friendships. Thus, considering the present findings, our last hypothesis (H4) was only partially confirmed.

3.4. Quality Assessment

The average quality score of the studies included in the present systematic review was 16.82 out of a total of 20 points (min = 13, max = 19, SD = 3.87). In accordance with the AXIS tool (Downes et al. 2016), this indicates the high quality of the studies (

Table 2. Quality assessment and total scores using the appraisal tool for cross-sectional studies (AXIS).

Authors (Year)	Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Q9	Q10	Q11	Q12	Q13 *	Q14	Q15	Q16	Q17	Q18	Q19 *	Q20	Total Quality Score/20	Quality Rating
Alfieri and Marta (2015)	Y	Y	N	Y	Y	N	N	Y	Y	Y	Y	Y	N	N	Y	N	Y	Y	N	NR	14	Moderate
Carlson and Iovini (1985)	Y	Y	N	Y	N	N	N	Y	Y	Y	Y	Y	N	N	Y	Y	Y	Y	N	NR	14	Moderate
Dhont and Van Hiel (2012)	Y	Y	N	Y	Y	N	N	Y	Y	Y	Y	Y	N	N	Y	N	Y	Y	N	Y	15	High
Dhont et al. (2013)	Y	Y	N	Y	Y	Y	N	Y	Y	Y	Y	Y	N	Y	Y	N	Y	Y	N	Y	17	High
Duriez (2011)	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	N	Y	Y	N	NR	17	High
Duriez and Soenens (2009)	Y	Y	Y	Y	Y	N	N	Y	Y	Y	Y	Y	N	N	Y	N	Y	Y	N	NR	15	Moderate
Duriez et al. (2008)	Y	Y	N	N	N	N	N	Y	Y	N	N	Y	N	Y	Y	Y	Y	Y	N	Y	13	Moderate
Eckstein et al. (2018)	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	N	Y	Y	N	NR	18	High
Rodríguez-García and Wagner (2009)	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	Y	19	High
Gniewosz and Noack (2015)	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	18	High
Hello et al. (2004)	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	19	High
Jaspers et al. (2008)	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	N	Y	Y	N	NR	18	High
Jugert et al. (2016)	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	19	High
Kulik (2004)	Y	Y	Y	Y	Y	N	N	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	17	High
McHale et al. (2007)	Y	Y	N	Y	N	N	Y	Y	Y	Y	Y	Y	N	N	Y	Y	Y	Y	N	NR	15	Moderate
Meeusen (2014)	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	19	High
Meeusen and Dhont (2015)	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	19	High
Miklikowska (2016)	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	18	High
Miklikowska (2017)	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	18	High
Miklikowska et al. (2019)	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	18	High
O’Bryan et al. (2004)	Y	Y	Y	Y	N	N	N	Y	Y	Y	Y	Y	N	Y	Y	Y	Y	Y	N	NR	16	Moderate
White and Gleitzman (2006)	Y	Y	N	Y	N	N	N	Y	Y	Y	Y	Y	N	N	Y	Y	Y	Y	N	NR	14	Moderate
Mean																					16.82
Standard deviation																					3.87

Legend Y = Yes, N = No, NR = Don’t know, Items 13 and 19 are reverse-scored. Note: Question related to each item: (1) Were the aims/objectives of the study clear? Methods: (2) Was the design appropriate for the stated aim? (3) Was the sample size justified? (4) Was the target/reference population clearly defined? (Is it clear who the research was about?) (5) Was the sample frame taken from an appropriate population base so that it closely represented the target/reference population under investigation? (6) Was the selection process likely to select subjects/participants that were representative of the target/reference population under investigation? (7) Were measures undertaken to address and categorize non-responders? (8) Were the risk factor and outcome variables measured appropriate to the aims of the study? (9) Were the risk factor and outcome variables measured correctly using instruments/measurements that had been trialed, piloted, or published previously? (10) Is it clear what was used to determine statistical significance and/or precision estimates (e.g., p value, CIs)? (11) Were the methods (including statistical methods) sufficiently described to enable them to be repeated? Results: (12) Were the basic data adequately described? (13 *) Does the response rate raise concerns about non-response bias? * (14) If appropriate, was information about non-responders described? (15) Were the results internally consistent? (16) Were the results for the analyses described in the methods presented? Discussion: (17) Were the authors’ discussions and conclusions justified by the results? (18) Were the limitations of the study discussed? Other: (19 *) Were there any funding sources or conflicts of interest that may affect the authors’ interpretation of the results? * (20) Was ethical approval or the consent of participants attained?

).

4. Discussion and Conclusions

The main aim of this systematic review was to summarize and discuss the research articles focused on the transmission of ethnic prejudice within the family, between parents and adolescents (i.e., vertical transmission), and between siblings (i.e., horizontal transmission). Studies that have analyzed the complex transmission of ethnic prejudice are still numerically scarce. In this systematic review, we specifically aimed at responding to four questions: (a) To what extent is there a vertical (between parents and children) and horizontal (between siblings) transmission of ethnic prejudice within the family? (b) Is this process unidirectional (from parents to children) or bidirectional (between parents and children)? (c) Which individual and/or relational variables influence this process? (d) Can adolescents’ intergroup contact and friendship experiences affect the family influence on adolescents’ ethnic prejudice? In this first part of the discussion, we will present the results from all the 22 studies included in this review while explaining and interpreting them. In the second part, the limitations and the implications of this study will be presented.

Starting with the first question, in line with our hypothesis (H1a), 19 studies analyzed the vertical transmission of ethnic prejudice and only three examined the horizontal transmission; none of these studies considered both processes in the same study. Most studies focused on the vertical type, probably considering parents as the primary socialization sources for adolescents’ ethnic prejudice, with a crucial importance in the development and significance of family bonds (Barni 2009). Concerning the strength of the transmission (H1b), the analyzed studies led to different conclusions: some studies showed a quite strong/large similarity or association between the parents’ and the adolescents’ interethnic attitudes (Dhont and Van Hiel 2012; Jaspers et al. 2008); some found a moderate similarity/association (Dhont et al. 2013; Meeusen 2014; Miklikowska 2017; Miklikowska et al. 2019), while others found only a small similarity/association (Carlson and Iovini 1985; Duriez and Soenens 2009; Hello et al. 2004; Miklikowska 2016).

However, as Miklikowska (2016) argued, the long-term effect of parental ethnic prejudice is more stable than that from peers, probably because the relationship with parents is more lasting than that with peers, who are part of a group in transitional periods, such as adolescence. In line with Allport (1954), direct interpersonal learning and conformity, which are two out of the three factors in the development of prejudice that are theorized to depend on parents, appear to be highly relevant in the process of prejudice transmission.

One interesting mechanism of the intergenerational transmission of prejudice from parents to children, involving authoritarianism, was suggested by Duriez and Soenens (2009). Authoritarianism was originally proposed as a deeply ingrained and fixed personality trait, but it has been recently reconceptualized as a malleable social-attitudinal variable of a broad ideological nature that is driven by core personality traits, i.e., by high conscientiousness and low openness (Sibley and Duckitt 2008). Given that authoritarianism is a relevant ideological basis of prejudice (Sibley and Duckitt 2008), it is to be expected that the intergenerational transmission of prejudice is partly rooted in the transmission of authoritarianism. Other studies have demonstrated that, in addition to exhibiting similar levels of prejudice, parents and children also display similar levels of authoritarianism (e.g., Duriez et al. 2008; Peterson and Duncan 1999). Moreover, Duriez (2011) identified one important social-contextual factor that helps to understand adolescent ethnic prejudice. If parents promote extrinsic goals at the expense of the intrinsic ones, their offspring are more likely to display ethnic prejudice. This effect occurs because adolescents tend to internalize the goals that their parents promote (e.g., materialistic ambitions), which, in turn, leads them to consider other people as competitors and potential threats to their wellness and, as such, they are more likely to develop SDO and RWA. As Duriez (2011) argued, to cultivate children who are open-minded and tolerant towards people with an immigrant background, parents may aim at downplaying the importance of extrinsic goals and try to create an environment that is characterized by satisfying relationships where they help others without expecting something in return (Duriez 2004).

The horizontal transmission between siblings was investigated by three studies (Alfieri and Marta 2015; Eckstein et al. 2018; McHale et al. 2007), which were consistent in reporting this transmission as ranging from moderate (Eckstein et al. 2018; McHale et al. 2007) to large (Alfieri and Marta 2015). Thus, the results highlighted a significant horizontal transmission (H1b). As already mentioned, siblings grow up together, often belong to the same cohort, and live the same period of the life (e.g., adolescence). All this can contribute to making them similar to each other in terms of ethnic prejudice. Moreover, as argued by Scabini and Iafrate (2019), the bond between siblings, which is not chosen but lasting, has a fundamental importance in individual development. Siblings approach and learn from each other in a context of solidarity as well as in confrontation and rivalry. Indeed, siblings might influence each other’s identity through sibling identification, by which they observe each other and start to behave similarly (Bank and Kahn 1975). This process seems to occur more frequently in the case of later-born siblings, who are more likely to identify themselves with their earlier-born siblings’ attitudes and behaviors (Whiteman et al. 2007). As a matter of fact, in the case of ethnic prejudice, it is the oldest sibling especially who is a “learning source” for the youngest one (Eckstein et al. 2018). In addition, Alfieri and Marta (2015) highlighted that when the oldest sibling has friends who have different ethnic origins, his/her prejudice decreases; most notably, it seems that the youngest sibling’s ethnic prejudice also decreases through this indirect contact.

In line with H2a, most of the studies we analyzed focused on vertical transmission, without empirically testing its unidirectional or bidirectional nature. There are, however, two exceptions (Rodríguez-García and Wagner 2009; Miklikowska 2016), which reach opposite conclusions and thus do not totally support the bidirectionality hypothesis (H2b). The first showed that the transmission of ethnic prejudice is unidirectional, while the second study highlighted the bidirectional nature of the transmission. These inconsistent results suggest the need for a more in-depth investigation of this aspect, preferably from a cross-cultural and longitudinal perspective. Indeed, cross-cultural comparisons in terms of prejudice transmission would allow to disentangle the specific role of the cultural context in this process. Parent–child similarity may be partially influenced by the predominant climate experienced (Barni et al. 2011). The support for the unidirectional transmission, found in a collectivist culture, should also be interpreted in the light of this consideration. Indeed, as suggested by Rodríguez-García and Wagner (2009), collectivist cultures are characterized by educational and parental styles oriented to conformism; children are therefore expected to conform to ingroup authorities (e.g., parents). Moreover, collectivist cultures differ from individualistic cultures in parent–child relationship qualities (e.g., warmth and closeness) that, as suggested by the findings of the present systematic review, might represent “transmission belts” (Schönpflug 2001).

Effectively, with reference to the third question that we set and consistent with the relative hypothesis, several factors, such as individual and relational variables, can affect this process. Indeed, we found a number of individual variables that intervene in the transmission of ethnic prejudice between parents and children, namely the parents’ and the adolescents’ sex, the adolescents’ birth order, and the parents’ education and income. In relation to sex, parents relate to their offspring differently depending on their own sex and the sex of their children (Scabini 1999). However, within research on ethnic prejudice, the role of sex has been underestimated and held to different conclusions. The few works on the topic have shown that adolescents mainly acquire intolerance and ethnic prejudice from the parent of the same sex, rather than from the parent of opposite sex (Rodríguez-García and Wagner 2009; O’Bryan et al. 2004). Other research, instead, did not find any significant effect of parents’ sex (Duriez 2011; Gniewosz and Noack 2015; Jaspers et al. 2008).

As far as the adolescents’ sex was concerned, Jugert et al. (2016) found a relatively strong effect of sex, with girls showing less ingroup prejudice than boys. The explanation for this difference may be related to the fact that girls are usually more sensitive to issues of ethnic and racial exclusion than boys (Killen and Stangor 2001). For example, girls score higher on measures of social and emotional competence than boys (e.g., Denham et al. 2003) and social competence correlates positively with children’s positive intergroup attitudes (Raabe and Beelmann 2011). In this regard, it is noteworthy that this difference in scores might always be related to family socialization processes. Indeed, girls are generally more socialized to values related to care for relationships and the respect for all people (Russo et al. 2019), because these values are strongly connected to the social role of “caregiver” that is traditionally ascribed to girls rather than boys (Barni 2009). This finding seems to be in line with Duriez and Soenens’s (2009) results, which indicate that boys, compared to girls, scored higher on racism. In contrast, Jaspers et al. (2008) did not find any sex effects, either for adolescents or for parents, in the transmission of attitudes towards ethnic minorities.

With reference to the adolescents’ age, Gniewosz and Noack’s (2015) study highlighted that early adolescents are more susceptible to their parents’ influence in terms of attitudes towards immigrants. Similarly, Miklikowska (2016) showed that parental prejudice predicted a change in ethnic attitudes from the beginning to the end of adolescence. This can be explained by the fact that early adolescence is a formative period for attitudes towards immigrants and also a time when parents can more strongly shape the development trajectories of their offspring’s attitudes regarding prejudice. This is explained by the theory of Sameroff (2009), which argues for a decreasing parental influence over time. As adolescents grow up, they tend to become less sensitive to parental influence (Roest et al. 2010). Indeed, with puberty, adolescents shift to a greater development of self-direction, and they start to choose their social environment more actively (Brown and Gaertner 2001; Miklikowska 2016).

Only one study highlighted the importance of birth order and its impact on the intergenerational transmission to adolescents of parental attitudes towards immigrants. Kulik (2004) showed that there is an intergenerational transmission of attitudes from parents to adolescents, although the strength of this impact is different in the case of mothers and fathers. The relation between the fathers’ attitudes and those of their sons were strongest for the firstborn and decreased according to birth order. The reverse trend was found for mothers. This was explained by the author through two perspectives, namely the parental compensation principle and the child’s preferential role model. Firstborn children, especially boys, internalize their fathers’ attitudes because of their need for a role model, and this is less likely to occur for the other children who tend to be less focused on power. This allows for the assumption that children play an active part in the socialization process by selecting their primary socialization source and determining the degree to which they wish to internalize the messages transmitted by their parents (Albert and Ferring 2012; Barni et al. 2017). It is relevant to take into account that Kulik’s (2004) study was conducted in the context of Israeli society, which is largely traditional and familistic and where the father is seen as the authoritarian figure in the family.

Regarding the parents’ and adolescents’ education, Hello et al. (2004) showed that this variable is a protective factor against ethnic prejudice. Despite this finding, the research has usually given little attention to the contribution of education to the transmission of ethnic prejudice. Still, in the few studies on the family, educational attainment has been included merely in order to control for status inheritance. Miklikowska (2017) and Jugert et al. (2016) pointed out that socio-economic background (SES, e.g., financial and educational) contributes to building a positive context for ethnic minorities. This can be explained in two possible ways, the first being that people with highly educated backgrounds tend to have highly educated friends, and this may promote tolerance. As for the second reason, it may be possible that being wealthy or growing up in comfortable conditions leads individuals to perceive less threat from ethnic minorities (Huijnk and Liefbroer 2012).

Beyond individual variables, our findings showed that the parent–child relationship quality, in terms of social learning, warmth, closeness, parenting styles, and family climate is involved in the transmission process. The intergenerational transmission becomes stronger when parents have a close relationship with their children. This can be firstly explained by the social learning theory that claims that children and adolescents learn attitudes through observation and imitation of parents and peers to gain their acceptance (Allport 1954; Bandura 1977). Jaspers et al. (2008) reported that in a warm family environment children are more influenced by their parents in their attitudes towards ethnic minorities. This means that a good relationship facilitates the transmission of attitudes from parent to child (Arnett 1995). If a child perceives the relationship as warm and trusting, the child will be more likely to value the same things as his/her parents. On the contrary, children who perceive their parents as less caring express a larger distance between themselves and their parents in attitudes towards ethnic groups.

The factors that encourage the transmission of ethnic prejudice include an authoritative parenting style, the presence of loyalty, and openness and credibility within family relationships, on which basis parents are perceived by their children as positive role models to imitate (Schönpflug 2001). In contrast, authoritarian parenting, which is characterized by a punitive and threatening approach full of criticism (Robinson et al. 2001), easily leads to aggressive and antisocial behaviors in children, as well as towards ethnic minorities (Hughes et al. 2006). Duriez (2011), whose study was included in the present systematic review, has shown how authoritarian parenting, which is based more on the promotion of extrinsic goals, stimulates competition, promotes ethnic prejudice, and increases aggressive attitudes towards immigrants. It conveys values such as conformity and preservation, rather than values related to openness and flexibility (Duriez et al. 2008). Authoritarian parenting not only predicts authoritarianism and ethnic prejudice in adolescents (regardless of parental prejudice level) (Carlson and Iovini 1985; Rodríguez-García and Wagner 2009), it also facilitates the intergenerational transmission of ethnic prejudice from parents to adolescents.

All in all, the results of our review suggested that authoritarianism, both as an ideology and as a parenting style, has a significant role in the intergenerational transmission of ethnic prejudice. Thus, it would be worthwhile for future studies to deepen the knowledge regarding the relationship between authoritarianism and ethnic prejudice within the family dynamics, as well as from a long-term development, bidirectional, and dialectical perspective. Moreover, as suggested by Meeusen (2014), we should start to look at the processes of transmission not in a “fragmented” way, but by jointly considering several “objects”, namely prejudice, authoritarianism, values, goals, and so on. The results emerging from our review underlined the strict connection between authoritarianism and ethnic prejudice, but it is also plausible to expect relationships between values or goals and prejudice. It is highly important to recognize the complexity of this influence within the family, as well as to involve all members of the family and consider the possible bidirectional nature of the process.

Finally, in line with the fourth hypothesis, contact between groups plays an important role in the ingroup’s experience with outgroup members, particularly among members who are in the developmental phase (such as in school, youth contexts of aggregation, peer relationships, etc.). In general, frequent and positive contacts outside the family with peers of different ethnicities lead to a reduction in prejudice. In addition, teenagers who have immigrant friends are less influenced by their parents’ prejudices towards foreigners than those who do not have immigrant friends (Miklikowska 2017). During adolescence, peer relationships represent an important source of learning in terms of values, norms, attitudes, and behaviors (Brechwald and Prinstein 2011). As such, having an immigrant friend can shape adolescents’ intergroup attitudes and then significantly impact on their levels of prejudice (Wölfer et al. 2016). Positive intergroup contact also significantly weakens the overall relationship between parental authoritarianism and adolescent ethnic bias because intergroup contact plays a buffering role in two ways. First, it alters the motivational processes that arouse authoritarianism because, through positive experiences with members of an outgroup, the threat perceptions are lowered. Therefore, the authoritarian–prejudice ratio is significantly weaker among adolescents with high levels of contact. Second, positive contact outside the family increases confidence in peer relationships and reduces the direct influence of parents (Dhont and Van Hiel 2012). This also suggests that intergroup friendships might be a protective factor against parent and peer prejudice (Miklikowska 2017).

The present systematic review has some strengths and limitations. The extensive and systematic literature search is one of the strengths. Explicit inclusion criteria and a transparent approach to data collection were also adopted. The main limitation is related to the fact that all the studies included refer only to Italian, Romanian, and English literature, and finally, only the English studies met the eligibility criteria; more studies that have analyzed this process may have been published in other languages. Another limitation is the fact that most of the studies included in the present review were carried out in Europe or in the USA, confirming the presence of the WEIRD (i.e., Western, Educated, Industrial, Rich, and Democratic) bias (Muthukrishna et al. 2020). With a specific concern for psychological studies on ethnic prejudice, the data are often collected in circumscribed areas, as such reaffirming prejudices and making invisible specific territorialized knowledge. It would be important for future studies to involve under-represented cultures in order to avoid the generalizations of WEIRD findings that do not fit the real situations of other countries.

Furthermore, almost all the included studies adopted self-reporting measures, and the responses may therefore suffer from a social desirability bias. Only one work, McHale et al. (2007), used a mixed-method study (questionnaires together with interviews), with the aim of investigating parents’ and their offspring’s daily activities and experiences. Diverse authors have argued that prejudice can also be expressed in a covert and subtle fashion (i.e., subtle prejudice; Pettigrew and Meertens 1995). From the studies assessed, only one analysis took this aspect into consideration (Alfieri and Marta 2015). Future research might also measure this type of ethnic prejudice by, for example, using implicit measures. In addition, most of the investigations involved dyads, while it would be more informative to include all family members to capture the complexity of the transmission process. It is important to take into account that families are strongly embedded in the community to which they belong; that is, they are characterized by specific traditions, norms, values, and attitudes (Scabini and Cigoli 2000). However, communities are more and more composed of other ethnic groups, which in turn are characterized by their own traditions, etc. To grasp this complexity, it would be important for future studies to deepen the transmission of prejudices through the family by adopting a bidirectional perspective, involving other significant micro-contexts (e.g., school or local communities), and also by considering the increasing family structure diversity and complexity of community composition. In line with those studies that conceptualize prejudice as a negative attitude towards immigrants and ethnic minorities (e.g., Jaspers et al. 2008), it is desirable that future studies keep focusing on prejudice against community minorities, expanding their investigation to consider the family transmission of ethnic prejudice in a multidirectional way. It is worthwhile noting that most studies included in the review focused on prejudice against immigrants. This is a form of prejudice significantly widespread among adolescents and young adults. In their analysis involving British people, Janmaat and Keating (2019) reported that attitudes of youths towards immigrants have become more negative over the past four decades. This trend has been attributed by the authors to the prevalent social conditions (e.g., “fewer opportunities in housing and employment, and a media environment that tends to link these challenges to a surge in immigration”, Janmaat and Keating 2019, p. 18), confirming the intolerance rising in times of crisis and enhanced competition for limited resources. This has also been happening for attitudes towards ethnic minorities, despite the educational expansion and secularization (e.g., Thijs et al. 2018). As observed by Pagani and Robustelli (2010), the motivations underlying youths’ attitudes towards immigrants are complex and often characterized by ambiguities; perceived threat plays an increasingly important role in these attitudes, given the competitive life pattern prevailing in our society. In the current multiple-crisis scenario, including the COVID-19 pandemic and the recent outbreak of the war in Ukraine, understanding the development of adolescents’ prejudice against immigrants, and their ethnic prejudice more in general, may provide critical insight. This is even more important if we think that attitudes towards immigrants represent one of the main organizing principles of youth political attitudes and their opinions on policies (Rekker 2016).

Practical Implications

This study has three main practical implications. First, it shows that the family plays an important role, and it is very important to provide information on the family dynamics associated with the transmission of ethnic prejudice. This knowledge can serve as a basis for the development of training aimed primarily at acquiring a greater awareness of one’s attitudes towards immigrants and the intergenerational meaning of such attitudes, leading secondarily to a reduction in prejudice.

Second, our findings highlighted that positive intergroup contact seems to be a protective factor against prejudice. However, despite the benefits of intergroup contact, not all families have the opportunity to engage in direct contact (Turner and Brown 2008). A first solution could be to increase parents’ and adolescents’ interest in intercultural and interracial interactions (Pauker et al. 2022). In this direction, there are several initiatives, such as the human library, which is a community event aimed at increasing awareness and reducing prejudice towards stigmatized groups (Bagci and Blazhenkova 2020). This intervention has shown its effectiveness on the cognitive, affective (e.g., trust and empathy), and behavioral (e.g., willingness to talk to outgroup members) aspects of group attitudes. A second solution might be to develop training aimed at establishing an intergroup contact indirectly (Crisp et al. 2009). In this regard, some research highlighted the efficacy of this intervention in modifying cognitive bias related to prejudice (e.g., Turner et al. 2007). To increase the attractiveness of these interventions, especially for adolescents, we consider the possibility of developing indirect intergroup contact training in the form of recreational and fun activities, such as video games (Kordyaka et al. 2020), in which all the family members could be invited to play.

Third, there are individual and relational factors that are related to the transmission of ethnic prejudice within the family. This requires the development of a multi-componential intervention in order to maximize its effectiveness in terms of prejudice reduction. Both individual and relational variables should be taken into account by bearing in mind that the family is integrated into a larger social context. Concerning this last point, prejudice and integration are usually approached mainly from a macro-perspective (see, for example, Whitley and Webster 2019). However, based on the evidence of the present review, we consider essential to also take into account the micro-context (e.g., family). This is especially relevant in the current increasingly multicultural society, which is also characterized by the recent refugee waves from Syria and Ukraine. In today’s social situation, parents are called upon to educate responsible future generations, open to others regardless of the origin and culture, in order to build an authentic global culture. However, this is not an exclusive responsibility of parents. Based on the evidence of a bidirectional transmission of ethnic prejudice (e.g., Miklikowska 2016), adolescents can also have an active role in contrasting prejudice by shaping their parents’ point of view (e.g., making them more open-minded). From Janmaat and Keating’s (2019) recent study, it emerged that today’s youth are more tolerant towards sexual and racial minorities than older generations. However, they interestingly hold similar or even stronger prejudice against immigrants compared to their parents and grandparents. In this regard, other micro-contexts, such as the school or local communities, should work to value immigrants and refugees as resources for the future so as to provide children and adolescents with valuable social experiences of intergroup exchanges over time. An increasingly multicultural society, such as ours, needs people who are more aware of all prejudices and its consequences.