Delinquency and Crime among Immigrant Youth—An Integrative Review of Theoretical Explanations

Although classical theorists tend to believe that immigrant youth are more delinquent than native-born adolescents, the existing empirical studies have shown the opposite. The current paper first gives a comprehensive overview of major theoretical explanations for the relatively lower level of delinquency among immigrant youth, including cultural perspectives, strain theories, social control theory, social learning theory, and social disorganization theory. The main argument is that immigrant youth who have not yet acculturated to the youth subculture of the host society are more law-abiding due to protections from their traditional traits ( i.e ., being more realistic, stronger ties with family/schools, less access to delinquent friends, and higher level of collective efficacy in homogeneous neighborhoods). All these theories are also applied to explain the generational differences in terms of delinquency: compared to earlier generations, later generations of immigrant youth are often more delinquent because they are more acculturated and the protective factors from their origins wear off over time. The continuing public and political bias toward immigrant youth has been explained by social constructionists. We further discuss the necessity of a synthesis of these theoretical approaches and the importance to examine both internal and international migration under similar theoretical frameworks in the modern era.


Introduction
The relationship between immigration and crime has long been a controversial issue in public debate and academic research.Although public discourse and classical theorists often link immigration with a heightened risk of deviance, a growing body of research introduced at the beginning of the 20th century shows that immigrant groups generally exhibit lower levels of delinquency and crime than native-born individuals, despite the former's relatively low socio-economic status and concentration in disorganized communities [1][2][3][4][5][6][7][8][9].A comprehensive review of the theoretical development and empirical evidence regarding the immigration-crime nexus is thus sorely needed.
Notwithstanding the general consistency in the abovementioned empirical results, a number of complexities inherent in research on the immigration-crime nexus merit further careful examination.In particular, there has long been an agreement that "it was not the immigrants themselves but their sons that constituted the big crime problem" ( [2], p. 157).The current review thus also aims at addressing the underlying reasons that descendants of immigrants are more likely to become involved in delinquency/crime than their first-generation counterparts.
We first review six broad strands of sociological and criminological theoretical development on the immigration-crime relationship and the possible generational differences: cultural, strain, social learning, social control, social disorganization, and social constructionism.These theories contribute significantly to our understanding of immigrant-related delinquency and crime in developed societies such as the United States (U.S.) and European countries, but significant room remains for theoretical revision, elaboration, and innovation.After introducing the theoretical origin and recent development of each theory, we discuss the current research gaps and possible theoretical extensions to address the complexities of the immigration-crime field, based on relevant empirical findings.

. Main Theoretical Arguments
Cultural explanations of immigrant-related crime/delinquency can be traced to culture conflict theory, as proposed by Thorsten Sellin [10] and more recently through subculture theories.Culture conflict theory contends that conflicting conduct norms or "cultural codes" between the old and new societies is the principal cause of crime among immigrants.To be specific, as individuals migrate to new areas, they bring with them sets of rules, norms, and mores from their homelands.These values are often different from and sometimes opposite to the dominant values in the areas where immigrants relocate.While each migrant group acts in accordance with its own set of rules, such rules may deviate from the norms of the receiving societies.Moreover, Sellin argued that cultural emphases represent tensions among individuals that blur the boundaries between "morality" and "immorality", resulting in an ambiguous void of "conduct norms" [10].In the absence of clear-cut rules, actors are likely to deviate from norms that are not self-evident [11].Therefore, delinquency/crime among immigrants may not just be an unconscious deflection of the dominant rules, but a rational choice not to conform due to the ambiguous conduct rules.According to subcultural deviance perspectives [12,13], an ethnic-minority/ migrant's underclass culture of origin embraces a system of values conducive to violence and other forms of delinquency.In other words, migrant populations might be more delinquent due to unsuccessful cultural adaptation to hosting societies with less-aggressive cultural orientations [14].

Empirical Evidence and Research Gaps
Historical and current studies provide opposing evidence of the culture conflict and subculture explanations.Earlier reports suggested that immigration and crime/delinquency are closely associated because the foreign-born are disproportionately represented in crime statistics [15].However, these findings have been strongly criticized for not considering the age and gender distributions of the immigrants.Most immigrants are young and male, both of which indicate a higher possibility of criminal involvement.After taking the relative number of various demographic groups between foreign-born and native-born residents into account, the Industrial Commission in the U.S. found that crime rates among the foreign-born are in fact lower than those among the native-born [1].This conclusion is supported in a report released by the Immigration Commission a decade later, which argues that immigration may suppress crime rates [16].The influential Wickersham Report issued by the National Commission on Law Observance and Enforcement in 1931 drew the similar conclusion that there was little evidence to confirm higher levels of criminal engagement among immigrants than among natives [2].Following the same line of research, contemporary studies have also found that immigrants are less criminal than their native-born counterparts.Using data derived from the National Longitudinal Survey of Youth (NLSY), Butcher and Piehl examined differences in immigrant and native-born criminal propensities, and found that youth born abroad are significantly less likely to be delinquent than native-born youth [4].
There has been some agreement that immigrants are not a random sample of the population of their original societies [17].Several theoretical arguments focusing on the pre-immigration characteristics of immigrants shed light on why a negative relationship between immigration and crime/delinquency might be expected.For example, selectivity theory contends that "persons who migrate are more ambitious, talented, and diligent than those who do not" ( [18], p. 538).Immigrants are thus less likely to engage in delinquent or criminal behavior because they are hardworking and ready to defer gratification for long-term advancement [7].Another explanation is the "immigrant optimism" hypothesis, which claims that immigrants remain committed to their aspirations of conventional success even when faced with hardship and socioeconomic disadvantage [19,20].Holding the belief that they have more opportunities in the receiving countries than in their home countries, immigrants are able to maintain the orientation toward conventional achievement, and thus, are less likely to engage in delinquent or criminal activities.Yet scholars face significant methodological and substantive difficulties in collecting empirical data to examine the specific traits of immigrants before they enter the host country and how these traits might change over time or across generations [21].

Main Theoretical Arguments
Instead of laying the blame on immigrants' cultural origins, Sutherland argued that immigration is not connected to crime; if anything, it is acculturation into American society that causes immigrants, especially second and above generations, to become more like native-born peers in all ways-including involvement in crime and delinquency [22].Some misplacement of Sutherland's view has led to the prevalent perception that the second and above generations of immigrants might be naturally crime-prone [7].Instead, this acculturation perspective addresses the level/pace of cultural assimilation and its effect on delinquency and risky behavior among immigrants and ethnic minorities.With more and faster exposure to American culture, the later generations of immigrants might exhibit higher criminality than the earlier generations, but still lower than or at most equal to the native-born population.It is simply a slow process of 'catching up' or 'naturalizing' to the baseline rate of their national counterparts [21].

Empirical Evidence and Research Gaps
Empirical studies have consistently supported the belief that more acculturated youth (typically indicated by language use, length of residence, and adopting mainstream values) tend to exhibit more, rather than less, delinquent behavior-a pattern linked to greater exposure to the dominant American culture [23][24][25][26].As previously mentioned, selectivity and optimism hypotheses offer theoretical reasons to expect that first-generation immigrants might enjoy certain protection or resilience from delinquency and crime [27].Previous research has provided solid evidence that such protection may wear off over time and across generations due to the acculturation/assimilation process.For example, using data from the Project on Human Development in Chicago Neighborhoods Longitudinal Cohort Study, Morenoff and Astor found that most types of violent behavior become more prevalent among the second and above generations of immigrants, compared to the first generation [8].However, studies in both the U.S. and Canada have indicated that the native-born youth are more likely to engage in delinquent and risky behavior compared to all foreign-born youth (even if they migrate into the host society before five or six years of age), regardless of their original nationality [21,28,29] Different from cultural conflict or subcultural arguments, the acculturation approach has received a high level of empirical validity.Nonetheless, it is criticized for assuming that all immigrants would finally adapt to the culture of the host society, which ignores the agency of immigrants and the interplay among individuals, cultures, and structures [8,30].According to recent studies in the migration/ immigration area [31], acculturation is only one of several models for immigrants' incorporation into the receiving society.Instead of considering acculturation as a linear process resulting assimilation to the host society eventually, the new approach of "segmented assimilation" points out different ways of adaptation among immigrants.Specifically, nowadays, immigrants in the U.S. may experience conventional integration (mirroring white middle class), exclusion (marginalized by the majority of the host society and stuck in separate enclaves), assimilation into the American underclass (adopting the adversarial subculture of the native poor), or multiculturalism/biculturalism/pluralism (validating immigrants' traditional values and competencies in the new culture).Migration researchers also argue that young generations of immigrants are different from adult immigrants in that they are more likely to fall into neurotic marginality (anxiously trying to meet the demands of both cultures), become "escapists" (alienated from both their original and the host societies), choose downward assimilation (over-emphasizing their culture of origin), or go toward over-acculturation (over-identifying with the mainstream culture).All of these alternative models draw little attention to the field of crime and delinquency, and at this stage, we cannot conclude that they are necessarily connected to delinquent behavior among immigrant youth [32][33][34][35].
Moreover, the acculturation approach is challenged for masking the detailed mechanisms underlying the acculturation-delinquency nexus, and more specific criminological theories must be applied here [36][37][38][39].We thus focus on illustrations of the mechanisms drawn from strain, social control, social learning, and social disorganization theories.In particular, we address how these theories explain the delinquency/crime propensities across immigrant generations.

Main Theoretical Arguments
Strain perspectives are applied directly to explain immigrants' experience.Traditional strain theory deems pressure to succeed materially in the face of insufficient and unequally-distributed legitimate opportunities to be the root cause of crime and other forms of deviance [40].Most immigrants choose to move to the U.S. for better economic opportunities, and they are likely to face institutional barriers in achieving economic success in the new society.The disparity between culturally valued goals and the limited legitimate means to achieve them in reality generates greater pressure for immigrants toward deviance compared with that experienced by even the most deprived U.S. natives [11].Thomas further explained that it is mainly because many immigrants are from developing countries where deprivation is normative and they expect an immediate pay off in a much more advanced hosting society [11].
While modern capitalism offers the lure of quick success and thus, more potential for immigrants' deviation, there might be differences across generations.In general, impoverished immigrants arrive in the U.S. with high expectations.However, their lower-level financial situations in their countries of origin make them more or less realistic.Many first-generation immigrants understand that nothing comes easily and readily defer their gratification for long-term development.Therefore, first-generation immigrants often exhibit much lower crime levels than do U.S. natives.Children of immigrants, however, might know little about their parents' difficulties prior to immigration, and they gradually lose the traditional virtues such as being hardworking and thrifty.In addition, the successive generations of immigrants grow up in a highly material and consumer-driven culture, much of which caters to youthful tastes, ideals, and values which are amplified as these immigrant youth become enmeshed in mainstream peer groups [11].When such material needs cannot be satisfied through legitimate means due to the institutionally blocked opportunities faced by all immigrants, immigrant youth might be attracted to drug markets or attach themselves to criminal gangs, making them much more deviant than their parents.
The stress of migration can be better conceptualized within the broader framework of general strain theory (GST) [41], now one of the most popular and compelling approaches to crime/delinquency.Extending Merton's structural-strain approach, Agnew brings in micro-level life events as sources of strain [41].Specifically, GST delineates a broad range of three strain-producing situations: (1) the failure to achieve positively valued goals, (2) the removal of positively valued stimuli, and (3) confrontation with negative stimuli that may lead to antisocial responses.Such strain-producing situations may trigger negative effects ranging from anger to anxiety and depression, which in turn prompt crime/delinquency to alleviate those negative emotions and/or strain.Another key aspect of GST is its recognition of conditioning mechanisms (e.g., social control/support, moral beliefs, peer exposure, etc.) that may intensify or moderate the effect of strain.Incorporating the acculturation literature, some scholars more recently specify an ethnically-relevant GST to explain the effects of post-migration strain on crime/delinquency.They suggest two major ways in which GST accounts for higher levels of delinquency among minority youth.One key way is that migrant youth experience quantitatively more and qualitatively different areas of strain.The four areas of strain that are of particular concern to migration and delinquency include economic strain, educational strain (unfair discipline, conflict with teachers, lower educational track, and negative relations with mainstream students), discrimination, and strain from victimization experiences (due to residing in neighborhoods with high crime rates).The other key way pertains to the conditioning mechanism: migrant youth are especially prone to cope with strain and subsequent negative affects through crime and delinquency, as they are deprived of the social support resources needed for strain moderation through legitimate means.Such theoretical extensions of GST received empirical support in the above two studies [42,43].

Empirical Evidence and Research Gaps
Pumariega and colleagues reviewed relevant empirical studies and find that different generations of immigrants face different sources of strain [35].They first summarize the unique stressors experienced by first-generation immigrants on their paths to their receiving societies.The two most common pre-migration stressors are traumatic exposure to negative events in home societies (i.e., torture, terrorism, natural disasters, war, or detention in refugee camps, etc.) and loss of positive networks (i.e., separation from their nuclear families, extended families, and/or relatives/friends).If first-generation immigrants suffer emotional disturbances due to the above stressors, their children may become more vulnerable because their parents themselves are overwhelmed and unable to help these children in the receiving societies.In terms of post-migration stressors, children and adolescents may face discrimination and prejudice in their adopted social settings (especially schools) with more intense expression from their immature peers compared to what their parents might experience in the adult world [44].Moreover, immigrant children and youth may face more chronic stressors and have worse mental health profiles than their adult counterparts because they suffer from all types of post-migration strain without a secured identity (purely cultural or multicultural), traditional values, realistic expectations toward success, and sufficient coping skills [45].Successfully acculturated youth might experience a lot of strain from significant family conflicts if their parents are poorly acculturated [46].These young people may also become much stressed since the acculturation makes them more aware of discrimination and blocked opportunities in the host society [47].In general, this GST framework helps us better understand why empirical results consistently show that later generations of immigrants are more delinquent or crime-prone than earlier generations.

Main Theoretical Arguments
Rather than addressing the strain sources and coping strategies of individual migrants, social control theory pays more attention to families and schools of migrants to account for the lesser involvement of migrants in crime and deviance, compared to their local contemporaries.Unlike Western culture, which promotes individualism and self-development, many non-Western cultures emphasize a strong reliance on and sense of obligation toward family members.Compared to local youth, adolescents growing up in immigrant families with such traditional family values are more likely to receive direct/indirect parental supervision, obey their parents' instructions, resist the temptations of maladjustment, and be motivated to behave in school because they do not want to harm or embarrass their families [48][49][50][51].Moreover, adolescents with familial obligations might exhibit successful school performance because doing so will help them obtain good jobs that will allow them to take care of their families [52].This family-centered orientation may also benefit the development of children's self-control since the family is the primary socializing agent of self-control [50,53].

Empirical Evidence and Research Gaps
Previous research has consistently identified Asian youth in the U.S. as less likely to become involved in delinquency and crime than black, Hispanic, and Native American adolescents [54,55].Social control theory is particularly useful in explaining this phenomenon.Traditional family values instilled by parents are more persistent among Asians than among other groups [56,57].They also inherit higher commitment to education and obedience to the teachers' authority under the encouragement of their parents [58,59].In a more systematic study using the framework of social control theory, Jang found that the lower criminality among Asian adolescents could be substantially explained by their differences in family and school bonding compared to other adolescents [60].Moreover, the explanatory ability of these variables tends to be invariant across four regional groups of Asian Americans (i.e., those from the Far East, East, Southeast, and South Asia).
How, then, can the increasing criminality across successive immigrant generations be explained?The mechanisms uncovering the causal connection between acculturation to the receiving society and rising delinquent involvement among immigrant youth remain mysterious.Although not directly linked with delinquency and crime, scholars in the migration field find that acculturation has negative effects on various immigrant youth outcomes.First, scholars have argued that the first and successive generations of immigrants often adapt to American society at different paces and this pattern, dubbed "dissonant acculturation," might increase parent-child conflicts and sometimes lead to generational role reversal (children become parents' parents), which might undercut parents' authority to control their children [61].Empirical studies have consistently found that rapid acculturation to American culture among later generations can reduce family cohesion and traditional familial attitudes [62][63][64].Moreover, acculturation to the individualistic and consumerist culture in the developed hosting society may reduce young immigrants' commitment to education and result in poor performance at school [60].Empirical studies have shown that levels of school engagement and efforts among immigrant children are associated with the time they have spent in the U.S., and first-generation immigrant youth have a higher level of interest in education, spend more time on homework, and exhibit better academic achievement than do their American-born counterparts [64][65][66][67][68][69].
In a more recent study, Bui directly tested social control theory to clarify such relationships [36].By analyzing 12,868 students from grades 7 through 12 in the United States, he confirmed that first-generation students are significantly less likely than their second-generation and third-plus-generation counterparts to report substance use, property delinquency, and violent delinquency.Furthermore, these differences can be explained partly by their background characteristics, previous delinquency, family relationships (measured by conflicts with parents), and school bonds (measured by troubles at school).These findings support the negative effects of acculturation on delinquency because acculturation increases parent-child conflicts and weakens attachment to school.Different levels of acculturation lead to variations in social control across immigration generations.

Main Theoretical Arguments
Attachment to families and schools not only directly results in a lesser likelihood of juvenile delinquency, but also has indirect effects on problematic behavior by reducing the opportunities of exposure to peer-based criminogenic risks [70].Differential association theory, as one of the most prominent theories of social learning perspective, has gained great empirical validity [71].The main argument of differential association theory is that if persons are exposed first (priority), for a longer time (duration), and with greater intensity (importance) to law-violating definitions than to law-abiding definitions, they are more likely to deviate from the law.Akers expanded the differential association theory and offered a more comprehensive social learning framework by addressing the important role of peer groups in encouraging youth deviant behavior.According to Akers, adolescents learn to engage in crime/delinquency from others (mainly peers) through three primary mechanisms, including reinforcement of deviant behavior, adoption of beliefs favorable to deviance, and imitation of deviant models [72].Compared to nonimmigrant adolescents, immigrant youth are more involved in the adult world and take on more adult responsibilities.For example, these young people are expected to help their parents negotiate legal and social matters because they are more acculturated, which may reduce their interactions with peers [46,48].Furthermore, immigrant youth receive more frequent and/or more serious parental supervision, constraining their opportunities to socialize with deviant friends [73].

Empirical Evidence and Research Gaps
Empirical research focusing on social learning perspective has provided insight into the seemingly negative association between immigration and delinquency.The evidence indicates that immigrant adolescents generally have limited access to peers, less autonomy over friend selection, and engage in less informal socializing with peers, leading to their lower levels of exposure to criminogenic peer-based risks [70,71,74].However, Dipietro and McGloin found that immigrant adolescents are more vulnerable than native-born youth when facing a similar level of exposure to peer delinquency [75].We need more studies to systematically consider the disadvantages in other aspects suffered by immigrant youth to understand why deviant peers might have greater effects on these adolescents.Regarding generational differences, the current evidence is mixed.Haynie and South suggested that newcomers are especially likely-at least in the short-term-to be integrated or accepted into peer groups whose members encourage deviant or problematic behavior, partially due to the fact that they are less likely to be included in mainstream groups at the beginning of their immigration [76].Dipietro and McGloin further found that first-and second-generation immigrant youth are generally more susceptible to the criminogenic influence of delinquent peers when compared to third-plus-generation adolescents [75].Compared to the successive generations, the first two generations of immigrant youth may suffer more family conflicts and unhappy school experiences in their process of acculturation.Some of these youth then become alienated from their families and mainstream peers and join ethnic gangs, hanging around with adolescents from similar backgrounds [35].Social psychological studies have confirmed the supportive functions gangs may provide to adolescents in turmoil by offering them solidarity, warmth, discipline, belonging, and protection [77,78].The third-and-plus generations of immigrant youth in fact are closer to their local counterparts in terms of peer delinquency because they are much more likely to accept the general youth subculture in the hosting society than previous generations [28].It is possible that the third-and-plus generations of immigrant youth tend to hang around with local peers and commit some other forms of delinquency instead of joining ethnic gangs.Thus, different generations of immigrant youth may have different reasons and ways in which to be influenced by delinquent peers.Beyond comparing the pure level of involvement of peer delinquency across generations, we need more empirical examinations to clarify the specific patterns and underlying mechanisms.

Main Theoretical Arguments
Unlike the above individual-and meso-level explanations, social disorganization theory addresses the structural barriers in immigrant communities that may hinder immigrants' collective social integration, such as ethnic heterogeneity, absolute/relative poverty, family disruption, and residential mobility.The theory regards these macro disadvantages as the underlying reasons for crime and deviance among immigrants because immigrants are more likely to live in a resettlement environment with such disorganized characteristics [79].To be specific, immigrants in the U.S. were historically often concentrated in ethnically heterogeneous communities with high population turnover.Shaw and McKay argue that heterogeneity and high residential mobility not only impede residents' ability to sustain reciprocal and interdependent relationships, but also intensify distrust and conflict within and among diverse groups, weakening informal controls of the neighborhood and producing high rates of crime [79].Corresponding to Shaw and McKay, the newly-developed segmented assimilation theory also suggests that immigrant youth who reside in disadvantaged inner-city communities are likely to adapt to the criminogenic subculture of the local poor or the underclass minorities [80,81].

Empirical Evidence and Research Gaps
In perhaps the earliest analysis of nationality differences in delinquency involvement, McKay reported variations in the rates of delinquency by nationality from 1900 to 1940 in Cook County Juvenile Court, Chicago [82].McKay discovered that although delinquency rates vary greatly when the children of immigrants are disaggregated by nationality, within similar neighborhood contexts the levels of delinquency among native-and foreign-born (all nationalities) boys tend to be close.This challenges public notions that certain nationality groups are more likely to be involved in crime than others.Rather, neighborhood context appears to be the driving force behind juvenile delinquency regardless of nationality.
Following McKay, an expansive body of literature has examined whether traditional social disorganization theory can explain the immigration-crime relationship among immigrant groups from Central and South America.Surprisingly, the answer appears to be "no" [83].In particular, high levels of violence have not been found in Latino communities, despite the fact that concentrated poverty, joblessness, and single parenthood are features of these neighborhoods.However, this does not mean that the effects of community are not important when examining the deviant behavior of immigrants.Analyzing data on nearly 3,000 males and females aged 8-25 from 180 Chicago neighborhoods over eight years, Sampson, Morenoff, and Raudenbush discovered that Mexican Americans show a significantly lower rate of violence compared to blacks and whites, after controlling for a number of factors including poverty and immigration status [9].Sampson further suggested that the crime drop in the U.S. since the early 1990s may be partially due to the increase in immigration [84].However, his main argument is less that immigrants have naturally lower criminality than native-born people, and more that immigrants living in neighborhoods with high immigrant concentrations enjoy a higher level of collective efficacy (sharing similar values and becoming highly involved in community issues), and thus, are protected from delinquency and crime.If they move out of these neighborhoods, the protection is reduced and they may become less law-abiding as a more U.S.-based American.Sampson's findings challenge the Chicago school's view that immigrants are more likely to settle in a disorganized neighborhood and therefore, might experience higher rates of crime.Instead, these homogeneous neighborhoods are beneficial for immigrants, although the communities bear many traditional characteristics of disorganization.The classic concept of social disorganization thus needs to be refined when interpreting the community effects on immigrants' behavior.
Sampson's observations on Mexican communities also help us understand the generational differences among immigrants.In the U.S. today, Mexican Americans tend to be first-generation immigrants, and they are more likely to inhabit Mexican communities where they can find their extended kinship and friendship networks.The communities provide various aspects of protection to these newcomers who have very low language and working skills in the hosting society and thus, decreased motivation and opportunity to engage in delinquency and crime [9].In contrast, hiding in an enclave is not really an option for immigrant youth, who must face and master the mainstream culture of the hosting country in school and social activities [35].As we summarized above, both successful (i.e., acceptance of U.S. youth subculture and conflicts with traditional parents) and unsuccessful acculturation (i.e., chronic strain as an immigrant) may increase their levels of delinquency.Sampson's study on Mexican communities thus needs to be extended so that we can collect longitudinal data to trace the possible behavioral changes among successive generations of these relatively law-abiding Mexicans.
Morenoff and Astor directly tested the framework of segmented assimilation to figure out the relationship among neighborhood structure, acculturation, and youth violence [81].They found immigrant youth in fact are less likely to engage in violence when they reside in neighborhoods with greater concentration of homogeneous immigrants.This finding indicates that the neighborhood context shapes the acculturation-violence link and a tight-knit immigrant community (even though located in the inner city and with concentrated poverty) should serve as a protective factor for criminogenic assimilation [8].However, none of the above studies compared different inner-city immigrant neighborhoods using comprehensive measures of social disorganization.It is possible that there are systematic differences between disorganized and non-disorganized immigrant communities.To refine the traditional social disorganization theory, we need gather a more representative sample of immigrant neighborhoods with various measures of "disorganization".

Main Theoretical Arguments
Prior empirical research generally shows immigrants to be no more criminal-prone than the native-born population.The above mainstream criminological theories have provided us valuable understandings on this fact.However, continued and baseless identification of a strong immigration-crime nexus still dominates the public and political discourse [21,85].The durable mental association between immigration and crime is partly driven by fear and prejudice, both of which are resistant to empirical evidence.The inconsistencies between known criminal harm and societal reactions to crime are socially constructed and well documented in the literature on moral panic [86].Moral panic denotes a fear of or concern with crime that is disproportional to the actual harm [87].The emergence of moral panic is often associated with "folk devils", i.e., a demonized group of people who are associated with the problem [86].Immigrants are often the "folk devils" in many societies.In the U.S. and some European countries, immigrants have been publicly blamed for soaring crime problems and disturbing the social order [6,7,[88][89][90][91].Even the judicial practices that are supposed to be the most neutral tend to systematically punish people who are, or are perceived to be, of foreign origin at a distinct disadvantage [21,92,93].Thus, immigrants tend to be typically criminalized groups rather than typical criminals due to less public tolerance and the greater severity of the penal institution.
We may wonder why the public and legal institutions target immigrants.One line of study explains the association between crime and immigration as a manifestation of intergroup conflicts.Critical criminologists argue that modern criminal justice systems not only protect the interests of the ruling class in society, but also act as mechanisms to control and exploit the subordinate groups [94].Focusing on intergroup relations, this perspective claims that racial and ethnic minorities are often faced with a harsher punitive response to the disorders associated with them because their presence is often seen as a threat to the dominant social group, which wants to use judicial tools to suppress rival groups.For example, in the U.S., residents in areas with higher percentages of ethnic minorities tend to perceive a higher level of crime, even when the actual crime rate is controlled [95].
In addition to intergroup conflicts, the resource expansion perspective along with symbolic politics perspective suggests that administrative and political interests also shape social responses to crime.The resource expansion perspective implies that the immigration-crime link is created and reiterated by law enforcement agents who regard it as an opportunity to expand their power in the bureaucratic structure.For instance, Chambliss and Sbarbaro found that police departments in the U.S. prefer to report a high crime rate when they require a larger budget, although sometimes police might present declining crime rates to claim that they are successful in their mission [96].From this perspective, immigrants are simply one group that law enforcers use to expand their power, while the presence of actual harm is not a necessary condition.
As for the symbolic politics perspective, Edelman pointed out that a political action regarding crime is not only an instrumental means to solve the "actual" problem, but also a symbolic gesture of political actors toward their audience [97].Political actors may "create" a social problem for political presentation to gain public support.According to this perspective, politicians exaggerate the criminal propensity of immigrants to detract public attention from some more serious social problems they are unwilling or unable to resolve.For example, foreign criminals became a favored topic of politicians in Japan in the 1990s, a period of economic recession and social anxiety [98].Here, the perceived battles against foreign criminals serve as a powerful symbolic event that enables leaders to act as heroes while more complicated issues such as the recession are left untackled.In such cases, the criminality of immigrants is not factual, but more likely 'scapegoat' oriented.
In summary, how the public and officials respond to crime does not directly correspond to the extent of actual criminal activity.Intergroup conflicts and administrative/political interests are potential sources of moral panic and punitive penology toward immigrants [85].Given that non-nationals are increasingly perceived as "anti-persons" to be dealt with solely through the penal apparatus of the state, it may result in a self-fulfilling prophecy of a crime-immigration nexus [93].

Empirical Evidence and Research Gaps
The existing evidence has been sufficient to show that the worries about "high" levels of delinquency and crime among immigrants are socially constructed, because the non-official data we mentioned above (with little political and administrative influence) generally report lower criminality among the foreign-compared to the native-born.However, constructionist arguments are often criticized for the difficulty they have in measuring the macro-level factors addressed by this approach, such as political concerns and group interests [85].We do need more studies to apply innovative measures so that we may directly test the various social constructional effects on the "perceived" level of delinquency and crime among immigrants.
Empirical studies have identified similar social constructional effects on the increasing arrests of youth in developed societies.To be specific, the public often holds some moral panic toward modern youth (i.e., perceived as violent, drug addicted, and sexually active), and the formal social control institutions also become less tolerant of adolescents' minor delinquent behavior [99].We have strong reasons to believe that the younger generations of immigrants may be more likely to be blamed and punished in the hosting societies because they bear double social constructional effects as a young person with immigrant status.However, we need to design and conduct feasible empirical research to directly compare the generational differences under this theoretical framework, of which there are few in the current literature.

General Immigration-Delinquency Relationship
Extant research on the immigration-delinquency relationship has yielded consistent evidence that immigrant youth are no more and often less delinquent than their native-born peers [1][2][3][4][5][6][7][8][9].According to the acculturation thesis, that is because immigrant youth (in particular, the first generation) have not yet adopted the youth subculture in the hosting societies.Then what is the difference between these youth and their local counterparts?Why are they different?Mainstream criminological theories further explained that compared with native-born peers, immigrant youth encounter less strain by holding realistic expectations in a material world, maintain stronger ties with families and schools, have less opportunities to interact with delinquent friends due to traditional family constraints, and enjoy more collective efficacy in their homogeneous neighborhoods.Despite the sufficient empirical support on the above theoretical arguments, there seems an ongoing myth about the high level of delinquency among immigrant youth.Such bias is socially constructed and mainly due to nowadays less tolerant social attitudes and policies toward immigrants.
This line of research still suffers from a number of limitations that hinder the possibility of drawing robust conclusions.First, all of these theories explaining delinquency/crime among immigrant youth focus on different levels of analysis: individual (general strain of individual life), group (influence of family/school and peers), community (social disorganization), and state (mainstream youth culture and policies/public attitudes in the receiving countries).Most previous studies only address one of these levels.In addition, there is often a tendency to generalize findings directly from one unit of analysis to another, although aggregate-level relationships do not necessarily mean a specific individual-level relationship, and vice versa [100].
To date, theorists have recognized the importance of the interplay between agency, culture, and structure when examining delinquency among immigrant youth [8,39,50].For example, general strain theory (GST) has been expanded to a macro-level strain theory (MST), which contends that individual-level variations in crime/delinquency are highly related to neighborhood-level strain and negative affect [101][102][103].Based on MST, we can hypothesize that if a social unit harbors a relatively stressful population, this elevates the likelihood that an adolescent immigrant in that social unit will interact with stressful people, experience more strain, and view delinquency as a proper mode of adaption to the stress of immigration.Unfortunately, there is little empirical research examining such simultaneous and dynamic influences of various level factors on immigrant youth delinquency, perhaps due to the difficulties of data collection.Without considering findings from different units of analysis, there is always a risk of mis-generalizing results, with the potential of drawing unwarranted theoretical or policy inferences [104].
More recently, scholars have noted that past studies at the aggregate level overemphasized the host societies, ignoring immigrants' home societies and the extended transnational space.As we have speculated, acculturation to the mainstream culture of the host society is not the only option for all immigrants, and their final risks toward delinquency are related to the traits they bring from their home environments and the ways in which such traits change during their continuing interactions with a new culture [21,31].Perhaps due to the constrained availability of data and the small sample sizes capturing information on various nationalities, most prior research on the immigration-delinquency nexus either highly relies on the general experience of Hispanic immigrants (not considering subgroups of Hispanics) in the U.S., or simply treats all immigrants as a homogeneous group regardless of their country of origin, migration history, cultural beliefs, and contexts of reception and incorporation.However, some reports do note certain distinctive patterns of criminal involvement.Unlike relatively law-abiding Asians and Mexicans, Italians often show high rates of involvement in violence while the Irish are known for their excessive drunkenness [10,22].Taft warned that failing to consider the specific immigration origins may cause aggregation bias [105]: the records of "bad" immigrant groups are being offset by the records of "good" immigrant groups and thus, the overall results show that immigrants are no more or even less criminal than their native-born counterparts.Since the immigration-delinquency link is more complex than what can be explained by either micro or macro level analysis separately, future research should pay more attention to the interplay between different units of analyses, including immigrants' home countries and transnational ties, to gain a clearer picture of how these factors work together to influence delinquent behavior among immigrant youth.Multilevel or nested data with sufficient sample size for major subgroups of immigrants are thus desired to collect for running such analyses.
Why are some immigrants more likely to be involved in crime/delinquency than others?Perhaps, these immigrants suffer multiple inequalities due to their appearance, religion, and/or language, together with the prevalent gender, class and race/ethnicity inequalities in the receiving society.This intersectional approach further differentiates immigrants into more detailed subgroups based on their gender, social class, and other characteristics.Although it provides us in-depth understandings of the diversities of behavioral patterns among different immigrant subpopulations, scholars have criticized that such intersectional analysis actually weakens the collective resistance of the disadvantaged group as a whole against unfairness [99].Instead of over-addressing multiple inequalities for all immigrants, future research could focus on those extremely vulnerable immigrant populations (e.g., black female immigrants) to explore how different inequalities interact with each other and how the intersectionality affects these women's assimilation and deviant behavior.

Generational Differences of Delinquency among Immigrant Youth
The literature indicates that there are significant generational differences in delinquent involvement as the successive generations of immigrants are far more delinquent than the first generation [23][24][25][26].As theorists have explained, these immigrant youth are more acculturated than earlier generations so that they are more likely to experience strain after being clearly aware of their blocked opportunities, to have conflicts with their traditional parents and school teachers, to socialize with local peers who emphasize individualism and hedonism, and to live a life beyond the boundaries of protective homogeneous immigrant neighborhoods.Although these theories all point out the different pace/level of acculturation across immigrant generations, they make their own contributions to clarify the acculturation-delinquency link through different angles.We need a more integrative investigation of the specific situations facing the second-and third-plus-generation immigrant youth by combining acculturation, various intervening/ mediating factors, and delinquency outcomes.
Moreover, with the development of communication and transportation, and the transformation of the economy in the receiving society, modern immigrant youth may be different from the "old" second generations, and future studies should put more emphasis on these "new" second-generation immigrants [106][107][108].With technological innovation, Western developed societies are experiencing a high demand at the low end for unskilled and menial service workers, and at the high end for professionals and technicians, with diminishing opportunities in between [109,110].The new second-generation immigrants come to understand the situation rather early and realize that without a college degree or higher, chances for fulfilling their career and life dreams are slim [107].The very high educational expectations held by the children of immigrants today are very different from the aspirations and actual achievements of children of Italian or Polish peasants a century ago [32,111,112].However, wide discrepancies between ideal aspirations of an advanced degree and the realistic expectations of getting one, especially among the more disadvantaged immigrant groups, may lead to more delinquent behavior as strain theory suggests [40,41].Thanks to modern communication and transportation techniques, an increasing number of immigrants, especially the new second generations (who are advanced enough to grasp modern skills), can easily maintain their ties with their home societies so that they might become so-called "transnational immigrants" [106,113].The recent-developed segmented assimilation theory may serve as a proper framework to figure out the relationship between these social changes and immigrant youths' delinquency.Specifically, the upgraded economic structure in the hosting societies and the rising transnationality in the whole world may provide more acculturation options in front of modern immigrant youth [48,50].That is, the new young generations of immigrants may be less likely to choose one-way acculturation than their previous counterparts.Does this mean that more immigrant youth will fall into the categories of neurotic marginality, "escapists", downward assimilation, or over-acculturation?Do these types of adaptations in the host societies bear more risks toward delinquency?A potentially fruitful future research pursuit would be to examine the unique experiences of these new second-generation immigrant youths to understand the effects of social development on immigrants' behavior.Cross-cultural comparisons would be also valuable since immigrant youth in different societies (i.e., Asian, European, and Middle East countries) may face different stages of social development and the special cultural/structural context (affecting policies, neighborhoods, families, schools, peers, and self-control) in each society also constrains the possible models of segmented assimilation in front of immigrant youth.

Implications for Studies of Internal Migration and Delinquency
Despite the progress summarized in this study of immigrant adolescents' delinquency, there is a lack of interrogation concerning the link between internal migration and delinquency.The rare interest in this topic among Western scholars might be partially due to the fact that the U.S. has largely completed urbanization, and internal migration seemed to reach an inflection point around 1980, subsequently declining in the past several decades [114].Despite U.S. academia's concentration on international migration studies, recent research on internal migration yields significant findings.Focusing on the dropout status among all black youths between ages 13 and 19, Thomas compared the dropout rates between children of native migrants, children in various immigrant groups, and native nonmigrants [115].The results showed that children of U.S.-born internal migrants had schooling advantages over children of U.S.-born nonmigrants while children of immigrants had more advantages over children of native-internal migrants because immigration is associated with higher levels of migrant selectivity than internal migration.Following the same line of reasoning, one may ask whether the advantage associated with having migrant parents is restricted only to children of immigrants when examining adolescent delinquency.Also, is there any difference in the extent of other forms of delinquency besides dropout between native internal-migrants and native nonmigrants?Is internal migrant youth generally more delinquent than immigrant youth?Can all of the theories discussed above be applied to explain the disparities in delinquent involvement, if any, between these groups?As a wide range of specific issues on internal-migration and delinquency remain underexplored, the expansion of research on native internal-migrant groups may offer useful insights into the determinants of their well-being and potentially shape future discourse on how broader migration processes might influence adolescent delinquency.
Finally, unlike Western developed countries that finished urbanization in a much earlier historical period, there is large-scale ongoing internal migration in most of the developing countries and its effect on individual behavior and social order has gradually aroused researchers' attention.In contrast to the Western evidence on the immigration-crime nexus, researchers in China contend that increasing numbers of rural-urban migrants are a main cause for the upward crime trends in contemporary China [116][117][118].This trend seems to be partially consistent with the modernization thesis proposed by many mainstream criminologists [119,120].That is, both violence and property crimes are likely to rise in the early stages of urbanization and industrialization, given that it takes time for rural migrants to adjust to their new urban lives.Accordingly, migrant adolescents may be more delinquent than their local peers.Existing evidence indicates that China's ongoing social transformation has affected its migrant youth and fuelled the production of delinquency [121][122][123][124]. Thus, it will be valuable to conduct more studies on the relationship between internal migration and delinquency in developing countries such as China and compare the findings with those of the West regarding the possible similarities and differences in the patterns and underlying factors associated with migration and delinquency.

Conclusions
Through a closer review of criminological/sociological theories and relevant empirical studies, this piece addresses the "immigrant paradox" which represents the positive outcomes of immigrants in the receiving societies despite public discourse and political agenda often links immigration with soaring delinquency and crime.Moreover, the paradox seems highly relevant to generational status since later generations of immigrants are more criminogenic than earlier generations.The reasons may lie in the fact that compared to those conventional first-generation immigrant parents, immigrant youth are more acculturated to the adversarial youth subculture of the host society, suffer qualitatively different and quantitatively more strain, receive less informal social control and more exposure to delinquency peers in less protective communities.As there is a rising global concern about the recent wave of immigration and its impact on the social well-being of the host societies, the need has become greater for social scientists to offer more integrative theories and empirical examinations on the effects of immigration on delinquency/crime and other social problems.In particular, we need multi-level research in diversified populations and societies since the above immigrant paradox that has been mainly identified in Latino communities of the United States may not be universal.