Muslim Religiosity and Juvenile Delinquency: A Systematic Review

While discussion of religiosity and delinquency has garnered attention in the past few decades, few studies have focused on how religiosity influences rates of delinquency among Muslim adolescents. In this systematic review, keywords were used to cull pertinent articles from two major databases (Scopus and EBSCOhost). In total, 14 articles were identified based on several inclusion criteria. In general, the studies selected showed that Muslim adolescents have a lower rate of delinquency compared to non-Muslim adolescents. However, when questions related to the measurement of delinquency (such as including violence) and the cultural context (such as including individuals who are first-generation immigrants of a non-Muslim-majority country) are taken into consideration, more complex trends are observed. Furthermore, many identified articles did not capture the essence of Muslim religiosity as conceptualized by some Muslim researchers, which has specific and unique properties that must be considered. This study demonstrates how Muslim religiosity protects against delinquency and has a potential use for intervention with Muslim adolescents.


Introduction
Religiosity is one of the types of bonds that can prevent delinquency among adolescents (Hirschi, 1969).Much of the literature on religiosity and delinquency has focused on non-Muslim populations, although lately more studies have explored the differences in delinquency rates among adolescents with various religious denominations (e.g., Baier 2014;Seto, 2021), including Muslims.The question is highly relevant and timely as conversations regarding Muslim proneness to crime is becoming more heated (Bershidsky, 2018;Seto, 2021).Against this backdrop, this article raises the question: based on the currently available evidence, how is Muslim religiosity linked with delinquency?To address this gap, this article reports a systematic review that synthesizes the current evidence on Muslim religiosity and delinquency among Muslim adolescents in different contexts and countries.
There is no shortage of studies attempting to understand why adolescents and youth are involved in delinquency and crime.One of the earliest social theories to understand and explain delinquency used the perspective of societal bonds (Hirschi, 1969).According to the theory, attachment to others comprises the internalization of norms and conscience that prevents an individual from committing crime through their attachment to parents, caregivers, families, and schools (1969).Attachments to families and schools have received wide attention in past studies (Yuksek & Solakoglu, 2016;Hoeve et al., 2012).In the current review, the focus is on religiosity as a form of bond that seems to have an unclear and complicated relationship with juvenile delinquency.
Earlier works that apply social bond theory in the context of religiosity has focused on the Christian religiosity (Hirschi & Stark, 1969).The study found that adolescents who attended church were not less likely to commit delinquency -and the authors concluded that religions did not matter in reducing delinquency among adolescents.However, in the same era, another study (Higgins & Albrecht, 1977) argued against the generalizability of Hirschi and Stark's (1969) study and found that church attendance did have a negative relationship with delinquency.According to the study, religiosity might matter more for the adolescents in the Southern United States than in the Northern United States.Making the relationship between religiosity and delinquency even more perplexing, another study replicated Hirschi and Stark's (1969) original findings, except for "victimless" crime such as the use of marijuana and alcohol (Burkett & White, 1974).
A few decades later, due to the complex relationship between religiosity and delinquency shown by studies, the idea of context was revisited (Stark, 1996), specifically on the "social contexts and social structures" (p.172) of society that are responsible for the mixed relationship between religiosity and delinquency.However, this is not entirely new-an earlier study already highlighted the importance of context (Higgins & Albrecht, 1977), where Southern adolescents responded to religiosity more than their Northern counterparts.This is also referred to as the "moral climates", a term referring to how the influence of religiosity is more pronounced in a religious community compared to a secular community (Stark et al., 1982).In later years, more studies began to acknowledge the importance of contexts in understanding the relationship between religiosity and delinquency; they also noted that the original hypothesis by Hirschi & Stark (1969) was too broad and required differentiation (Cochran & Akers, 1989).
Various aspects of the human experience can play a role in moderating the relationship between religiosity and delinquency.To explain the influence of contexts, three models were proposed to understand why prior findings regarding the relationship between religiosity and delinquency have been mixed (Baier & Wright, 2001): (1) the moral community hypothesis, (2) the effect of religosity on nonvictim crimes, and (3) methodological variations in past studies.
According to the moral community hypothesis, the nondeterrent effects of religiosity on crime should only be observed in areas where religiosity is accepted as a valid basis to determine the legitimacy of values and actions (i.e., morality).Hence, according to the hypothesis, a place that is highly secularized (e.g., Northern United States as in Higgins & Albrecht's study in 1977) will see a lower deterrent effect of religiosity on crime compared to less secularized, or more religious, communities (e.g., Southern United States).
Second, the effect of religiosity on crime was usually stronger when the effects were analyzed separately for victimless crimes such as substance abuse versus crimes with victims such as violent and property crimes.This pattern calls attention to the importance of the type of delinquency investigated in each study.Studies on religiosity have operationalized crime and delinquency in different ways, ranging from petty crimes to violence (e.g., Johnson et al., 2001;Li, 2014).Some studies also focused on radicalization and terrorism (e.g., Pedersen et al., 2018;Rousseau, et al., 2019), but these behaviors seem to be in a "league of their own" and require an analysis separate from studies that focus on more conventinal forms of delinquency.
Third, the methodological variations argument states that studies with smaller sample sizes that focus on particular backgrounds (e.g., White respondents) typically yield larger effect sizes for religiosity on crime when compared to studies using larger sample sizes.Because of this, the third model suggests that there is value to smaller studies, contrary to the commonly held belief that the bigger the size of the sample, the better the study.Instead, having a too large of a sample size may decrease the quality of the sample because "the sampling design becomes more difficult to carry out effectively" (p.17).
Much of the literature on the relationship between religiosity and delinquency has been set in the context of Christian and Western cultures.However, the Muslim population around the world is increasing year by year (Desilver & Masci, 2017), and there is a prevalent public perception that often associates Muslim populations with crime (Seto, 2021), especially in some countries like the United Kingdom.As such, given the complexity surrounding the relationship between religiosity and delinquency, and the rarity of academic discourse on the dynamics of Muslim religiosity and delinquency, this article aims to provide a systematic review of the recent literature on this topic.This article will report the most salient themes from findings of studies investigating the relationship between various facets of Muslim religiosity and delinquency, as well as current gaps that may serve as future avenues for research.

Characteristics of Muslim Religiosity
Although different religious faiths share some characteristics regarding the aspects of rituals and beliefs, Muslim religiosity possesses complexities unique to the religion of Islam.At its most basic form, Muslim religiosity comprises three levels: Islaam (outward submission and practices), Imaan (faith), and Ihsaan (spiritual excellence) (Parrott, 2019).Islaam is basically the five pillars of practices, beginning from the declaration of Shahadah (belief) to completion of Hajj (pilgrimage).Imaan is the affirmation in the belief that comprises six elements: the God, the Messengers, the Books, the Angels, the Resurrection, and Qadar (divine decree).Finally, Ihsaan is when a Muslim adheres to excellence in the Islamic lifestyle, including treating others well, forgiveness of wrongdoings, giving charity, and other socially responsible acts or deeds.
Given these different elements, Muslim religiosity is unique and adherence to it is complex to measure.One scale developed to capture the elements of Muslim religiosity conceptualized it into five components: Beliefs, Attitudes, Spiritual Behavior and Connection, Institutional Connection, and Contribution (BASIC) (Desouky & Umarji, 2021).However, although BASIC has been shown to correlate with markers of wellbeing among Muslims worldwide, which might indicate a criterion validity, a formal assessment of its validity and reliability has not been established.
Researchers from other parts of the world have attempted to develop specific measures of Muslim religiosity.A measure was developed based on the three levels of faith as mentioned above (Islaam, Imaan, and Ihsaan) (Mohd Mahudin et al., 2016).One of the strengths of this measure is that the researchers have established its good psychometric properties.However, the researchers stated that this measure was developed for use in an organizational setting, indicating it may have limited utility and applicability.

Muslim Religiosity and Delinquency
Religiosity has a complex relationship with delinquency, and this is even more the case for Muslim religiosity.As mentioned above, criticisms have pointed out that most studies on religiosity and delinquency have been conducted in Western and Christian contexts, questioning the generalizability of the findings to other religions (Brauer et al., 2013).Given the extensive arguments for the expansion of studies on religiosity and delinquency to other contexts (e.g., Stark 1996), data from other religious and cultural contexts must be collected and compared with their Western counterparts.This is especially important as the world is becoming more diverse with respect to religiosity (Pew Research Center, 2015) and the Muslim population is projected to be nearly equal to the Christian population in a few decades.In the past few years, some -albeit limited -studies on religiosity and delinquency have examined other religions, including Islam.
At first look, the findings of studies on Muslim religiosity and juvenile delinquency have been mixed.Some studies found a negative relationship between Muslim religiosity and delinquency (Brauer et al., 2013;Seto, 2021), such that individuals who reported being more religious also committed fewer delinquent acts.However, the opposite findings found that Muslim religiosity was related to increased delinquency (Baier, 2014;Carol et al., 2020).
Several hypotheses can be offered to explain these discrepancies in findings.First, although all these studies examined Muslim religiosity as a common variable, the contexts in which the Muslim samples were recruited were different.Some studies were conducted in Muslim majority countries such as Bangladesh (Brauer et al., 2013) and some in non-Muslim majority countries like the United Kingdom (Seto, 2021), and Germany (Baier, 2014;Carol et al., 2020).In this aspect, Germany is regarded as a secularized state where atheism has become the predominant background among the Germans (Thompson, 2012), which might affect the Muslims' sense of belonging; however, Muslims in Britain reported feeling "British" and part of the British cultures, signifying their level of positive assimilation within the region (Rashid, 2021).This arguably highlights the importance of the "contexts" -i.e., areas where the data collection takes place.In this regard, it matters if the countries are Muslim majority or non-Muslim majority, which brings forward issues often examined by sociologists, such as acculturation.Revisiting the model posed by Baier & Wright (2001), the level of acceptance of religious values in a society may influence the relationship between religiosity and delinquency.
The second explanation relates to the argument of abstinence (Carol et al., 2020), which refers to Muslims who practice a lifestyle adhering to Islamic rules by, for example, not drinking alcohol.In the context of this review, this is an important point to ponder due to several reasons.First, Islam is argued to be a highly collectivistic religion with emphasis on proper dealings with others as much as the ritualistic practices (Bassiouni, 2012).This is parallel to early arguments related to social bond theory (Hirschi, 1969), by which it is the socialization of accepted norms and values that forms a well-functioning individual.It can be argued that these elements of socialization that are promoted by Islamic values diminish over time within non-abstinent Muslims.Therefore, for non-abstinent Muslims, their "bond" with their main community is weakened.
These mixed findings regarding Muslim religiosity and delinquency prompt questions, the answers to which further illuminate the processes and mechanisms on how Muslim religiosity can provide deterrent effects against committing delinquent acts.One of the considerations that should be discussedis the potential influence of collective rituals among Muslims.For example, a study demonstrated that it is more collective religious rituals such as going to mosquerather than religious devotion itself-that predict the support for the idea of suicide attacks (Ginges et al., 2009).Although the current review is not framed to understand suicide attacks, Ginges and colleagues' ( 2009) study provided early understanding of how collective rituals should be an important consideration when exploring the dynamics of religiosity in delinquency.Ginges et al.'s (2009) study drew controversy by demonstrating the role of religion in promoting suicide attacks through religious priming, and they argued that this might be dependent on geopolitical factors as there are some groups, such as Tamil Tigers of Sri Lanka, that still support suicide attacks without being attached to any organized religion.On the contrary, studies elsewhere have shown that religious priming may yield positive effects on individuals, such as prosociality (Batara et al., 2016), honesty (Aveyard, 2014), and cooperative behavior (Xygalatas, 2013).However, studies on religious priming have further raised the question on the generalizability of the findings since many of them have been conducted in Western contexts.Furthermore, religious priming might not work the same way for Muslims living in a Muslim country as the level of threshold of activation for the religious priming is lower in Western contexts that are usually less religious and more secular (Aveyard, 2014).

Recent Systematic Reviews
There have been a few systematic reviews of studies examining the relationship between religiosity and delinquency (Adamczyk et al., 2017;Hardy et al., 2019;Johnson et al., 2000).In general, these reviews have demonstrated the protective factor of religiosity against delinquency.However, the available systematic reviews were done without specific considerations of the complex nuances of Muslim religiosity and its relationship with delinquency.For example, in one review, being "Muslim" was mentioned only in discussion of how being a religious minority can put someone in the position of being stigmatized (Adamczyk et al., 2017), which was similar to the review by Hardy et al., (2019).Therefore, understanding the link between religiosity and delinquency among Muslim adolescents is needed to expand the literature on the scope of the topic.

The Current Study
There is a large-scale perception that relates crime to the identity of being Muslim, which is not parallel to findings of some studies among Muslim adolescents.Although the research on Muslim religiosity and delinquency has been sparse, a systematic review of the existing studies is warranted to identify trends of knowledge, the scope of existing research, and available gaps that should be addressed.Specifically, given the perplexing findings from past literature, this review seeks to understand the contexts by which Muslim religiosity plays a role as a protective factor against delinquency among Muslim adolescents.

Methods
To conduct the systematic review, the PRISMA (preferred reporting items for systematic reviews and meta-analyses) framework was adopted (Liberati et al., 2009).The PRISMA framework suggests a series of steps comprising identification, screening, and assessment of eligibility and inclusion.Application of these steps is described below.

Article Selection Process
The research on religiosity and delinquency is multidisciplinary, and its multidisciplinary nature necessarily shaped the process by which the articles were selected for this review.In this selection process, this study identified studies through a search in multiple databases available in EBSCO, using databases that transcend the topic of criminology as some articles on delinquency and religiosity are published in noncriminological journals and databases.The keywords that we used were "delinquency," "Muslim," and "religiosity".This study did not include other deviance-related terms such as "violence" because in this first ever systematic review of studies related to Muslim religiosity and delinquency, this study aimed to confine the discussion specifically to delinquency.Furthermore, to select the articles to be included in this review, the following inclusion criteria were used: 1.The studies were conducted with delinquent adolescents or youth.At first, only articles reporting studies on adolescents below 18 years old were considered to be included; however, this decision is purely legal based on the existence of laws of many countries that specify a child as an individual below 18 years old.To acknowledge the many arguments by past social scientists claiming that the age of children can be dynamic (e.g., Sawyer et al., 2018), articles that focus on adolescents who are a few years older than 18 years were also included, as long as the articles clearly used the term adolescents or children (for whom the concept of delinquency is relevant).2. The sampling focus of the studies included Muslim adolescents regardless of context and countries.However, this criterion became tricky during the search as there were some articles that only focused on Muslim adolescents, with no comparison data with non-Muslim adolescents.Furthermore, although some ethnicities are more associated with being Muslim (e.g., Malays in Malaysia), this study excluded articles that only refered to respondents by their ethnicities without stating their religions, to avoid being presumptive of the respondents' religions.3. The articles are published in English.4. The full text of the articles could be obtained.5.The manuscript reports an original study with empirical findings.
To search for the article in the databases, a series of steps that was operated through the advanced search function was followed.The following combination of keywords was used to search the title, abstract, and the full text of articles in order: "(delinquent OR delinquency) AND Muslim AND/ OR religiosity".After the selection of articles, the inclusion criteria that include the age were applied.After the selection of the articles, their contents were coded.The content of the articles was coded by the first author.Given that extracting the content of articles for the review was straightforward with very little room for interpretation, no analysis of interrater agreement was deemed necessary.The second author provided feedback on the research questions, the coding scheme and the write-up of the article.

Characteristics of Included Studies
Figure 1 below summarizes the process of identifying and selecting the articles, verifying the selection, and determining each article's eligibility against the inclusion criteria.Ultimately, 14 articles met the aforementioned criteria to be included in this systematic review.We included all articles using only Muslim samples and both Muslim and non-Muslim samples.Table 1 below summarizes the characteristics of the studies in the final pool.

Results
The fact that only 14 articles could be included in the final pool of selected studies shows that research on this specific topic is still scarce in the literature on delinquency.However, there is a noteworthy increase in studies meeting the inclusion criteria over time and particularly very recently.The first two studies were published in 2008, and five studies (35%) were published in the years 2020 to 2022.
As per the location of the studies, most of these studies were conducted in non-Muslim-majority countries, which are European countries, the United States (US), and Israel (nine studies, 64%).Only six studies were conducted in Muslim-majority countries (one study included both Muslim-and non-Muslim-majority countries in Eastern Europe and the US: Klanjsek et al., 2012).Among the non-Muslim-majority countries where these studies were conducted, Germany was the most common location (3 studies, 21%).
When analyzing the selected studies, three major themes emerged: (1) inter-religious comparisons; (2) the use of alcohol as a form of deviance among Muslim adolescents; and, (3) problems in operationalization of Muslim religiosity.

Quality Appraisals of Studies
The studies selected in this review were appraised by two professionals (one was a non-author) using a study quality assessment tool developed by National Institute of Health (NIH) (2021) for observational cohort and cross-sectional studies.The tool contained 14 items with the evaluators choosing one of the following options: "yes", "no", or "other" (such as "cannot determine" and "not available").The items are (the items are abbreviated as "Item 1" until "Item 14" in Table 2): 1) Was the research question or objective in this paper clearly stated?2) Was the study population clearly specified and defined? 3) Was the participation rate of eligible persons at least 50%? 4) Were all the subjects selected or recruited from the same or similar populations (including the same time period)?
Were inclusion and exclusion criteria for being in the study prespecified and applied uniformly to all participants?5) Was a sample size justification, power description, or variance and effect estimates provided?6) For the analyses in this paper, were the exposure(s) of interest measured prior to the outcome(s) being measured?7) Was the timeframe sufficient so that one could reasonably expect to see an association between exposure and outcome if it existed?8) 8) For exposures that can vary in amount or level, did the study examine different levels of the exposure as related to the outcome (e.g., categories of exposure, or exposure measured as continuous variable)?9) Were the exposure measures (independent variables) clearly defined, valid, reliable, and implemented consistently across all study participants?10) Was the exposure(s) assessed more than once over time?11) Were the outcome measures (dependent variables) clearly defined, valid, reliable, and implemented consistently across all study participants?12) Were the outcome assessors blinded to the exposure status of participants?13) Was loss to follow-up after baseline 20% or less?Were key potential confounding variables measured and adjusted statistically for their impact on the relationship between exposure(s) and outcome(s)?
Because this tool was developed also for cohort studies, some items were irrelevant to be included in the scoring process (i.e., Item 6, 7, 9, 10, 11, and 13), as the items assessed elements of longitudinal research.After the omission of the irrelevant items, there were eight items included in the scoring process.The evaluators discussed their ratings and achieved agreement in the final decision.The ratings are summarized in Table 2.However, it is important to note that, according to the guide, these are not fatal flaws, rather merely the indication of certain risks for bias.The articles' scores of "yes" range from 3 to 7, out of eight items, which demonstrate a fair quality given that these are cross-sectional studies.

Inter-Religious Comparisons
One of the most salient findings offered by these studies are the comparisons of rates of delinquency among adolescents of different religious affiliations.Of course, this kind of finding is not offered by studies with mono-religious samples (e.g., Eseed & Khoury-Kassabri, 2018;French et al., 2008;Khan, et al., 2020).For the rest of the articles selected, seven of them offered inter-religious comparisons as part of their findings (Carol et al., 2020;Donath, et al., 2011;Klanjsek et al., 2012;Pedersen et al., 2015;Schmitt-Rodermund & Silbereisen, 2008;Seto, 2021;Wahab et al., 2021).Generally, studies that presented inter-religious comparisons supported the notion that Muslim adolescents have a lower rate of delinquency ranging from petty offences to substance abuse.However, a deeper examination of these studies makes it apparent that several factors might affect this trend and thus must be taken into consideration.First, the adolescents' context or living situation was shown to play an important role.Carol et al. (2020), Donath et al. (2011), andKlanjsek et al. (2012) found that generally Muslim adolescents have a lower rate of crime, but Schmitt-Rodermund and Silbereisen (2008) demonstrated that in a non-Muslimmajority country like Germany, the immigrant generation matters in this relationship.In their study, first-generation Muslim adolescents with an immigration background showed a higher rate of delinquency, which the authors argued to be due to the maladaptive aspect of acculturation.
At the same time, it appears that how delinquency is defined also affected whether Muslim adolescents were identified as showing a higher or a lower level of delinquency.Muslim adolescents had a lower level of delinquency in studies that included in their measures of delinquency petty crimes such as theft all the way through more severe crimes such as rape.However, although this review did not specifically search for "violence" (i.e., physical violence) as part of the search terms, some studies in the selection included violence as part of delinquency, and in these studies Muslim adolescents were reported to have a higher rate of delinquency compared to non-Muslim adolescents (Carol et al., 2020).Since this study did not include "violence" as part of the search term, a meaningful conclusion from this cannot be made.However, this trend may be looked at from the perspective of the Antiascetic Hypothesis in which religiosity is argued to only serve as a protective factor for adolescents against petty crimes and not violence (Miller & Vuolo, 2018).
In addition, according to Baier ( 2014), the complex relationship between religiosity and violence might also be due to reasons related to Muslims being situated in non-Muslim-majority countries, which is parallel to Schmitt-Rodermund and Silbereisen's ( 2008) maladaptive acculturation argument.Furthermore, the positive relationship between Muslim religiosity and violence was not observed in Seto's ( 2021) study in the UK, which might give support to Schmitt-Rodermund and Silbereisen's ( 2008) maladaptive acculturation argument, as research has shown that Germany is more popular with refugee Muslims and the UK is more popular among regular Muslim immigrants (Pew Research Center, 2017).Being regular immigrants, adaptation to new environments might be easier given their more acceptable status among the public compared to moving as refugees.
Nonetheless, studies that offer inter-religious samples conducted in Muslim-majority countries or that specifically assess acculturation are needed to determine if acculturation is a prominent influence when it comes to the relationship between Muslim religiosity and delinquency.In this review, as of now, the studies that offer these comparison findings were conducted among immigrants and non-immigrants (except for Klanjšek et al., 2012).

The Use of Alcohol as a form of Deviance
Alcohol use has been a focus of delinquency studies given that alcohol is related to other externalizing behavioral problems such as delinquency (Najman et al., 2019;Shahzad et al., 2020), although depending on context, the use of alcohol in itself is not a delinquent act (however, some studies explicitly regarded alcohol consumption as a delinquent act, for example, Seto, 2021).The discussion of alcohol use as part of the discourse on delinquency is not unique to studies focused on Muslim adolescents.However, for studies that included Muslim adolescents, the socio-cultural aspects of Muslim religiosity was a focus.Moreover, it has to be noted that although in some countries, adolescents are legally allowed to drink by the age of 16 (The European Agency for Fundamental Rights (FRA), 2018), Muslim adolescents are bound by the rule of their religion that forbids alcohol consumption regardless of age.In this review, seven studies included alcohol use as part of their predictors or dependent variables (Donath et al., 2011;Eseed & Khoury-Kassabri, 2018;Khan, et al., 2020;Pedersen et al., 2015;Seto, 2021;Shahzad et al., 2020;Wahab et al., 2021).
As for the inter-religious data discussed above, the general trend shows some prevalence of alcohol use among Muslim adolescents, but less use than non-Muslim adolescents (Donath, et al., 2011;Wahab, et al., 2021).Studies that only assessed mono-religious samples (where all respondents were Muslim) found lower alcohol use among their Muslim samples compared to use among adolescents from other religions assessed in other studies (Eseed & Khoury-Kassabri, 2018;Khan, et al., 2020;Shahzad et al., 2020).
A study by Pedersen et al. (2015), however, deviates from the findings of the other studies as mentioned above.According to the authors, there was a positive relationship between alcohol use and a Muslim immigrant background.They argued that "the counterintuitive positive association between Muslim affiliation and alcohol problems is due probably to the fact that only regular alcohol users were included in these analyses" (p.1602).This is possible, but this review offers the alternative argument that the higher rate of alcohol use among Muslim immigrants reported by Pederson et al. (2015) might be due to Muslim adolescents' being situated in a non-Muslim-majority country, which might expose them to issues such as maladaptive acculturation, as argued by Schmitt-Rodermund and Silbereisen (2008) in regard to the general trend of delinquency rate as discussed above.

Operationalization Problems of Muslim Religiosity
As when studying any complex variables, there is also a need to look into the operationalization of the variables, in this case religiosity.The first observation that this review made is that five of the articles selected only used religious affiliations (i.e., by simply indicating what religion the respondents identify with) to identify Muslim respondents (Donath et al., 2011;Khan, et al., 2020;Schmitt-Rodermund & Silbereisen, 2008;Shahzad et al., 2020;Wahab et al., 2021).
For three articles, religiosity was measured using a scale that operationalized religiosity through three dimensions: relationship, request and retribution (Eseed & Khoury-Kassabri, 2018;Khoury-Kassabri et al., 2015;Massarwi et al., 2019).Two articles used the concept of intrinsic religiosity because it was argued that intrinsic religiosity is free from external pressures (Carol et al., 2020;Klanjsek et al., 2012).In addition, two articles used religious attendance to measure religiosity (Pedersen et al., 2015;Seto, 2021).It can be argued that using religious attendance is contrary to The full phrasing of the items is provided under "Quality Appraisals of Studies".Item 6, 7, 9, 10, 11, and 13 were omitted from the final scoring intrinsic religiosity as it is considered as outward or extrinsic expression of religiosity.Finally, one article recognized the importance of abstinence and its interplay with the status of religiosity (Carol et al., 2020).Lastly, out of the 14 articles, only two studies used a measure that was specifically developed to conceptualize Muslim religiosity (French et al., 2008;Sahin & Unlu, 2021).French et al. (2008) built a checklist based on the religious rituals expected to be practiced by Muslims in Indonesia, such as performing daily prayers and fasting in the month of Ramadan.Finally, Sahin and Unlu (2021) developed a scale for Turkish adolescents, measuring three facets of the Muslim religiosity: religious beliefs, religious practices, and the religious social environments.This is an important point to ponder given the overwhelming tendency for these studies (11 out of 15 studies) to look at Muslim religiosity from a non-Muslim point of view, likely impacting aspects of methods and measurements.By not considering the complex nature of Muslim religiosity, the issue of methodology and measurements lack foundation.For example, Carol et al. (2020) found a higher rate of violence among non-abstinent Muslim adolescents, would this be explained by a lack of Ihsaan as a component of Muslim religiosity among the respondents?Therefore, from the perspective of this trend, it can be argued that the results would become clearer if the nuances of Muslim religiosity are taken into consideration.

Discussion
In the past decades, and especially these past few years, more studies have focused on the link between Muslim religiosity and juvenile delinquency -even so, the findings seem to be mixed.This systematic review sought to synthesize the evidence related to Muslim religiosity and delinquency.Specifically, the current trends in the evidence, the strategies used by past studies to view and measure religiosity and Muslim religiosity, and the ways Muslim religiosity influences adolescents' delinquency levels.Although there are other systematic reviews on the concept of religiosity in general and certainly on delinquency, other reviews have not specifically focused on Muslim religiosity.In summary, these are this review's main findings: (1) Muslim adolescents are shown to generally have a lower level of delinquency; (2) Muslim adolescents living as minority in non-Muslim-majority countries have higher tendencies for delinquency and violence; and (3) past studies did not take into consideration the complex nuances of Muslim religiosity in operationalizing religiosity among Muslim youth.
This review revealed that contexts (i.e., Muslim religiosity or the cultures of the adolescents) should be taken into consideration when assessing the relationship between religiosity and delinquency, as argued by Baier & Wright (2001) and Stark (1996).It is clear from the current review that Muslim adolescents had different experience in delinquency, compared to adolescents of other religious backgrounds based on the findings.In this regard, overall results suggest that Muslim adolescents experience a lower level of delinquency compared to adolescents of other religious backgrounds.
However, this relationship was inconsistent across studies when considering Muslim religiosity and violence, as studies like Carol et al. (2020) found that Muslim adolescents committed a higher level of violence, but Seto (2021) found the opposite.Baier (2014) made an argument related to a cultural property of the Muslim population, citing the role of high acceptance towards the norms of masculinity among Muslims.Baier's (2014) observation is similar to observations from Carol et al. (2020) probably due to the social position of Muslims in the country (Germany) while Muslims in the UK (which is a context in Seto's study) are more integrated and a main part of the UK population.Nonetheless, these studies pointed to the importance of considering the broader social contexts (as per Stark 1996) of the living situation among these Muslim adolescents, and how these contexts may provide the sense of belongingness.
From a practical perspective, the results reaffirm the argument that being a minority is impactful towards various facets of well-being, especially in the developmental context of the adolescent migrants.Practitioners, especially working with minority youth in the non-Muslim countries, should be aware of the roles played by acculturation, assimilation, and prejudice in affecting the ways youth cope with their migration and minority status in the countries.Recognizing this considers bi-directionality of adolescent development, where the adolescent's development does not only occur through interactions with others, but also through exposure to different levels of the ecology (e.g., being a migrant in a new country) (King et al., 2021).
Furthermore, another alternative perspective could be pointed out in addition to the maladaptive acculturation argument raised.It is also a possibility that the documented prevalence of prejudice in the Western society towards Muslim adolescents (e.g., Seto, 2021;Elkassem et al., 2018) plays a role in the heightened level of delinquency among Muslim adolescents in certain contexts.The perspective from the side of the society (i.e., prejudice) is also important to be considered, consistent with the arguments of labeling theory (Kroska et al., 2017).The theory argues people often act how they are labeled.In the context of this current review, the prejudice among the Western society against Muslim youth may have impacted the youth's behavior and specifically delinquency-meaning that Muslim adolescent delinquency may have little to do with being Muslim, but a lot with being the target of prejudice and discrimination.
The issue of alcohol consumption among adolescents is also raised as it has been shown that there is a relationship between alcohol consumption among adolescents and other problems, including violence (Baier, 2014;Pedersen et al., 2015).Studies such as Donath et al. (2011) and Wahab et al. (2021) showed that while there is some alcohol consumption among Muslim adolescents, rates of alcohol use among Muslim adolescents are generally found to be lower than among their non-Muslim counterparts.The consideration of alcohol consumption among Muslims is complex given that the prohibition of alcohol consumption is more salient among the Muslim population (Seto, 2021), which means that they have a more restrictive relationship with alcohol and that alcohol consumption is more likely to be viewed as a form of deviance on its own, contrary to other religions.
For non-Muslim adolescents, alcohol consumption is not a moral issue and only restricted by laws.For the Muslim population, alcohol consumption has been regarded as a moral issue (Pew Research Center, 2013).This raises the question of whether the link between alcohol consumption and delinquency (e.g., Najman et al., 2019) would be more pronounced among Muslim adolescents (given the prohibitive factor of alcohol).Future studies should investigate if alcohol consumption truly explains the findings of past studies in which Muslim adolescents demonstrated a higher level of violence compared to adolescents of other religious (or non-religious) backgrounds.Some arguments have been offered in the past, such as the acceptance of masculinity norms (Baier, 2014), maladaptive acculturation process (Schmitt-Rodermund & Silbereisen, 2008), or methods-related issue (Pedersen et al., 2015).However, no studies have yet to investigate if the link between violence and alcohol consumption is due to, for example, a lack of intrinsic religiosity, which would be conceptualized by the concept of ihsaan.Furthermore, it is also important for these studies to be done in a Muslim-majority setting to see if the link between alcohol consumption and violence is present there.
Finally, this study found that one of the most salient gaps that exists within the literature on Muslim religiosity and delinquency is how the concept of Muslim religiosity is operationalized.A first step to improving this field of research would be to develop and utilize scales specific to Muslim religiosity.However, given that inter-religious comparison is one of the most common themes in these past studies, using a scale designed exclusively for Muslim respondents would render it impossible for inter-religious comparison to be made.Still, given that no studies have truly used the Islamic concepts of religiosity, for example as denoted by Desouky & Umarji (2021), the true extent to which Muslim religiosity, with its different elements, affects the levels of delinquency is currently unknown.This is especially noteworthy when Sahin's (2021) study provided early evidence that different elements of Muslim religiosity have different relationships with delinquency.Currently, the majority of the literature has only offered insight into the influence of Muslim religiosity through the perspective of general religiosity (using the properties of Muslim religiosity that are shared with other faiths such as abstinence, religious attendance, and the role of the religious institutions).
Given that the views of the public on the relationship between Muslims and crime may be biased and inaccurate (Seto, 2021), this article argues that a current review focused on the latest evidence on Muslim religiosity and delinquency is needed, and yielding such a review was the aim of this study.However, the current review has several limitations.First, since this review aimed to focus on the concept of delinquency and not conflate it with other deviance-related terminologies such as "violence", there is a possibility that this review has missed articles that also focused on deviance, but did not explicitly use "delinquency" as a keyword or main concept.Future research should expand the current review by also including other deviance-related search terms.Second, the current study did not consider articles published in other languages.There is likelihood that due to the existence of Muslims in parts of the world where English is not the main language, there should also be studies that are reported in languages other than English.It is possible that these studies would provide some insights not available in the current review which should also be addressed in future studies.

Conclusion
The link between Muslim religiosity and juvenile delinquency has been a focus in delinquency literature; -however, the findings have been mixed.This systematic review attempted to understand the patterns of the link between Muslim religiosity and juvenile delinquency, an important topic that has been a subject of discussions and debates among researchers, policymakers, and the public.All in all, results highlight a few important observations on the complexities surrounding the relationship between Muslim religiosity and juvenile delinquency.In addition, while the essence of Muslim religiosity was not truly captured, the preliminary observation here that can be made is that Muslim religiosity seems to be a protective factor for youth in Muslim-majority cultures and partiall complexities surrounding the relationship between Muslim religiosity and juvenile delinquency.In addition, while the essence of Muslim religiosity was not truly captured, the y in non-Muslimmajority cultures.Therefore, this review reinforces the idea that religiosity should be used as a resource in intervention for those already believing.Even so, other interplaying factors may undermine the protective element of religiosity.This is especially true when considering the cultural factors or specifically cultural contradictions between the youth and the society in which they live.

Fig. 1
Fig.1The process of article selection

Table 1
Chacateristics of the studies selected

Table 2
Ratings of Quality Assessment (National Institute of Health, 2021)