Keywords

These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

1 Introduction

From the earliest ages of life young people are drawn into relationships with peers. Given the opportunity, even toddlers are inclined to orient towards age mates. This inclination grows through the rest of childhood to become particularly prominent during adolescence, when many adults express fears that peers will rival or surpass adults in their ability to influence the actions and thoughts of young people. Such concerns have some merit, as researchers routinely report that the strongest correlate of deviant behavior among teenagers is the deviance level of their friends (Elliott and Menard 1996). In such research, however, the capacity for peers to exert positive influences or provide health-enhancing resources is often understated or overlooked. In this chapter we will review evidence of the ways in which peers enhance positive youth development in several domains of young people’s lives.

Over the course of childhood the peer social world is dominated by dyadic and small-group relationships. Individual friendships tend to be transient and heavily dependent on continued proximity (e.g., sharing the same school classroom or neighborhood) and involvement in shared activities (Berndt and Hoyle 1985). By middle childhood, larger clusters, or friendship groups, emerge. Throughout childhood, membership in friendship groups fluctuates considerably, even month to month, but slowly grows more stable (Cairns et al. 1995).

The advent of adolescence changes peer systems structurally and functionally. Growing concern with reputation or status introduces notions of hierarchy both within and among groups, such that some groups have more prestige or authority than others, and within each group a hierarchy of member status or influence can arise as well (Adler and Adler 1998; Dunphy 1963). Groups may take on identity labels (e.g., jocks, brains, loners, Latinos) reflecting normative activities and values expected of group members (Brown and Larson 2009).

Dyadic relationships are transformed as well. Friendships grow more stable and more intense (Berndt and Hoyle 1985), only to yield some of their authority in time to growing romantic and sexual interests that evolve into emotionally intense romantic relationships (Connolly and Johnson 1996). Occasionally, these two types of dyads are counterbalanced by antipathetic relationships involving an aggressor and victim or joint aggressors (mutual antipathies, Witkow et al. 2005). Sibling relationships also evolve over this period, often emerging as highly influential dyadic ties, although usually with a mix of positive and negative elements (McHale et al. 2006).

Collectively, then, young people must learn to navigate a complex peer social system comprised of several types of dyadic relationships and multiple forms of small group interactions. Suffused within these relationships are issues of identity, status, normative expectations, and social acceptance. Different dynamic forces are at work in these relationships and have varying impacts on a young person’s development and behavior. Peers may be a source of modeling appropriate attitudes and activities. They may provide instrumental and emotional support, and they may exert direct and indirect pressures to guide behavior choices. They may also serve as buffers to moderate the influence of other forces, including the demands or expectations of parents or other adults and even other peers.

Assessing or even appreciating the full effect of peers on children and adolescents is an overwhelming task, so it is not surprising that, to date, researchers have focused on a narrow set of issues and outcomes. The bulk of evidence considers peer effects on undesirable behaviors such as delinquency, drug use, or dropping out of school. Some investigators have turned attention to more positive peer influences and effects. Their studies have concentrated on five major domains: academic achievement or school engagement, extracurricular participation, behaviors that promote physical and sexual health, prosocial behavior (or the discouragement of antisocial activity), and positive psychosocial adjustment.

We concentrate attention on these five domains, striving to illustrate the many ways in which and conditions under which peers contribute to positive youth development. Our intent is to illustrate the nature of positive peer dynamics through childhood and adolescence, but this should not be construed as an exhaustive analysis of these dynamics. On the basis of our review we offer suggestions for future research and potential applications and prevention/intervention efforts aimed at fostering positive developmental trajectories of young people.

2 Academic Orientations and Achievement

The domain with the most extensive evidence of peers’ contributions to positive youth development concerns academic achievement and other school related behaviors. Investigators have explored the types of peer relationships and types of influence processes that are most salient in this setting; there is also some indication of the conditions under which peers promote positive academic behaviors.

Although it is common to find that students who do well in school have friends with high academic achievement levels as well, much of this association may be due to youngsters’ selection of friends who share their academic orientations, rather than friend influence. Longitudinal studies, however, indicate that friends are a significant source of influence beyond “selection” effects (Cook et al. 2007; Crosnoe et al. 2003). Friend effects may be contingent on the features of the relationship or the context in which it occurs. Altermatt and Pomerantz (2003), for example, found an effect only for reciprocated best friendships, not for unilateral or less salient friendships. Vaquera (2009) found that, especially for Hispanic youth, who are less likely to have close friendships and especially less likely to share the same school with close friends, the mere presence of a best friend in their school boosted their sense of school belongingness, which in turn enhanced academic performance.

One aspect of the effectiveness of friends is the social support that they provide, either to combat a sense of loneliness and social isolation – again, especially among ethnic minority youth (Benner 2011) – or to bolster a young person’s sense of academic competence (Bissell-Havran and Loken 2009). Unlike peer achievement levels, which seem to affect an individual’s achievement only when the relationship is close and reciprocated, peer support provides a more general effect. Even measures of general peer support (the amount of support a young person feels from peers in general) are associated with high levels of school engagement (Li et al. 2011) and the pursuit of high achievement levels (Wentzel 1998).

The influence of siblings is more difficult to discern because of the numerous features of this relationship that must be considered, including the age difference between siblings, gender composition of the pair, the quality of their relationship, and whether the younger or older sibling is the target of investigation. In a study of Latino adolescents that considered all of these factors, Alfaro and Umaña-Taylor (2010) found gender differences in influence pathways. For girls, having older siblings was associated with higher quality sibling relationships, which in turn was related to stronger achievement levels. For boys, the presence of older siblings also was related to higher quality sibling relationships, but this was related to academic achievement via the support that siblings provided for achievement. A more puzzling set of findings emerged from a sample of African American and European American early adolescents (Bouchey et al. 2010). Increases in the older sibling’s level of academic achievement predicted increasingly levels of achievement for the early adolescent. However, the amount of support the older sibling said they provided predicted lower levels of achievement for the target child. Likewise, the level of perceived support from the older sibling was inversely related to achievement levels and academic self-concept – but only for mixed sex dyads.

One clue to these findings may lie in the forms of influence that investigators have suggested are typical in sibling relationships. Whiteman and Christiansen (2008) outlined three different types of sibling influences: emulation, in which a child tried to copy the behavior of a sibling, differentiation, in which the child tried to do something different from the sibling to demonstrate that he or she was a separate and distinct person, and example setting, in which the child consciously behaved in a given way to set a good example for a sibling. A subsequent study (Whiteman et al. 2007) added a fourth process: competition, in which one sibling tried to surpass another’s achievements in a given domain or behavior. Although this lexicon of influences has not been applied to studies of achievement related behavior, one can imagine how it might differentiate young people who try to match, surpass, or substantially underperform a sibling’s achievement level, depending upon the personality characteristics, family dynamics, and relationship features that characterize a pair of siblings.

Moving beyond dyadic relationships, some investigators have considered the role of broader peer group norms on young people’s academic behaviors. Wentzel and Caldwell (1997) found that group membership was a stronger predictor of early adolescent school performance than either being highly accepted by peers or having reciprocated friendships. This group effect can be traced to norms about academic achievement that are common within most adolescent groups. Kindermann (1993) reported that although the membership of early adolescent cliques was unstable, achievement norms persisted over time, even as different young people moved in and out of a group. In other words, the group sets achievement standards that are sustained despite group instability; these standards influence group members beyond the effects of individual dyadic relationships. Nevertheless, the group may not be equally influential in all aspects of academic orientations. Ryan (2001) reported that, controlling for factors affecting young people’s selection of group affiliations, their group membership was a strong predictor (from fall to spring of a school year) of changes in members’ liking and enjoyment of school and their academic achievement levels, but not of the importance they placed on achievement or their expectancies for success in school.

In sum, investigators have consistently found evidence of potential positive influences that peers can exert on young people’s interest in and achievement at school. These influences are rooted in both dyadic relationships and broader group affiliations. The strength and nature of such influences are contingent on features of the peer relationship, individuals’ backgrounds (such as ethnicity or gender), and the nature of the social context (e.g., location or ethnic composition of the school). As a result, more extensive and systematic exploration of various peer relationships and affiliations is needed to fully understand the dynamics of peer influence in this domain of youths’ behavior.

3 Extracurricular Participation

School or community sponsored extracurricular activities are generally regarded as healthy pursuits and contexts that promote positive youth development. In truth, activities vary in the degree to which – or at least the consistency with which – they enhance positive development. Certain sports, for example, seem to be associated with both positive and problematic behavior (Blomfield and Barber 2010; Mays et al. 2010). The preponderance of positive outcomes for extracurricular participants has fueled an interest in factors that encourage youth involvement in these activities (Eccles and Templeton 2002). It is conceivable that peers are instrumental in young people’s decision to join extracurricular activities, or that pursuing relationships with co-participants serves as an incentive for involvement. It is also possible that the peer relationships occurring within extracurricular activities foster more positive development than relationships pursued outside these activities. In contrast to academic achievement, the research about peer factors is limited in this domain, both in quantity and sophistication. Our commentary must be regarded as speculative.

Blomfield and Barber (2010) assessed correlations among extracurricular involvement, friend characteristics, and outcomes in a sample of Australian youth. Grouping reports of extracurricular participation into five types of activities, the investigators found different peer profiles depending upon type of activity and different ways in which peer factors might account for associations between extracurricular participation and outcomes. For example, whereas those involved in team sports reported more friends who drank regularly, adolescents in individual sports had an unusually high number of friends who did well in school and encouraged them to excel academically as well, and an unusually low number of friends who skipped school. Friends’ level of alcohol use mediated the association between participation in team sports and alcohol use; friends’ disinclination to skip school mediated the negative association between individual sports participation and truancy. The study did not determine whether or not friends on whom participants reported were activity co-participants, so it is not entirely clear how the activity context figured into peer influences. This shortcoming is common to studies in this domain. In a sample of early adolescent, predominantly African American youth, Wilson et al. (2010) reported that participants in an after-school program who spent most of their time playing football or basketball were less likely to report positive peer influences toward academic achievement than those who selected other types of sports or non-sport activities, but the authors did not ascertain whether or not friends made the same activity selections in the after-school program.

Some indication of the importance of the social atmosphere established in the extracurricular activity comes from a study of sports team participants by MacDonald et al. (2011). Those who reported positive interaction with peers (among other factors) within the sports team reported stronger personal achievement and enjoyment of the activity than those describing a more competitive atmosphere within their team.

As in the academic domain, sibling influences on extracurricular participation are contingent on whether a young person is attempting to emulate, differentiate from, or set an example for a sibling. In Whiteman et al. (2007) study, modeling was common with regard to all types of extracurricular activities, but differentiation was also a frequent motive behind sports participation. Girls were more interested in sports when their older sibling was and they reported influence from that sibling; but this effect was not apparent among boys. A closer analysis of these sibling effects is clearly warranted.

4 Health-Enhancing Behavior

In addition to extracurricular participation, investigators have examined the role of peers in promoting two healthy behavior patterns, namely, physical activity and safe sexual practices.

Physical activity level is a strong concern at adolescence because it tends to decline at this age, which can lead to serious weight gains that, in turn, are correlated with other problematic health conditions (Patrick et al. 2004). Sexual activities also grow more salient in adolescence as young people begin sexual relationships and can establish behavior patterns (unprotected sex, sex with multiple partners) that compromise their health.

4.1 Physical Activity

It is not surprising to find that physical activity levels of friends are correlated in adolescence because friends are such central activity companions during this life stage. An important question is whether this correlation arises from the inclination to select friends who share one’s level of physical activity or from the tendency to be influenced by a friend’s activity level. Evidence from one study suggests that both factors are at play. In a longitudinal study of Australian 8th graders, de la Haye et al. (2011) found that young people tend to select peers who share their activity level as friends; but even controlling for this selection effect, friends have considerable impact on changes in activity level. In fact, the friend influence effect was nearly three times as large as the selection effect.

A major component of the influence effect is the degree of support friends provide for physical activity (Duncan et al. 2005; Raudsepp and Viira 2008). Support may take various forms – from encouraging words to joint participation in activities to instrumental assistance that makes participation possible (e.g., driving a peer to sports practice). The importance of these supportive functions has been found in urban as well as rural youth, in children as well as adolescents.

4.2 Safe Sex Practices

The question of whether similarities between friends are a function of selection or influence factors also emerges in research on adolescents’ sexual practices. Based on two waves of data from the National Longitudinal Study of Adolescent Health, Henry et al. (2007) found that adolescents tend to befriend peers with similar attitudes, but not necessarily similar behaviors regarding sexual activity. Over time, however, friends tend to grow more alike in terms of both sexual attitudes and practices. This convergence can involve movement towards either safer or riskier sexual behavior. Among a sample of economically disadvantaged Belgian 18-year-olds, most of whom were sexually active, friends’ positive attitudes toward safe sex practices were associated with higher rates of condom usage (Hendrickx and Hilde Avonts 2008). Similarly, among a sample of Latino youth, Kapadia et al. (2012) reported that perceived peer norms favoring safe sex were associated with higher rates of condom use and lower likelihood of engaging in sex with multiple partners.

The friendship dynamics related to health behaviors can become complicated. In an intriguing study that followed a set of university students before and after spring break trips that featured major partying in resort settings, Patrick et al. (2011) found that friends sometimes made pacts to depart from their normal behavior patterns and get drunk or have more indiscriminant sexual liaisons. The promise that a friend would watch over these activities and not let a person go “too far” actually enhanced risk taking. On the other hand, undergraduates who placed more emphasis on developing a strong friendship network were less likely to venture into health compromising forms of drug use or sexual activity.

Siblings also can play a role in adolescent sexual behavior. In one longitudinal study of U.S. high school youth, Kowal and Blinn-Pike (2004) found that conversations with older siblings about safe sex practices were correlated with enacting these behaviors in sexual activities. Such discussions were more common among adolescents who reported close relationships with older siblings.

A potentially important source of influence missing from most studies to date is a young person’s sexual or romantic partner. Here, again, selection factors (choosing to become involved with someone who shares similar attitudes and experiences with safe or riskier sexual practices) are likely to be important, but as relationships develop and sexual interests become more intense, attitudes may change. Do partner influences supersede those of friends or siblings? Are there gender, ethnic, or age differences in the relative weight given to various peer sources? These are questions that deserve more research attention.

5 Prosocial Behavior

Counterbalancing the extensive literature on peer influences on antisocial behavior (especially, various forms of delinquency and drug use) is a modest but growing body of work on prosocial behavior. Operationalized in different ways in different studies, this term encompasses such activities as cooperation, sharing, and helping others, but it also refers to peer efforts to discourage or disavow problem behavior (e.g., Maxwell 2002). Unfortunately, many authors fail to specify the items included in their measure of prosocial behavior.

Prosocial peer influences are not uncommon. In fact, when given an opportunity to describe rates of prosocial as well as antisocial peer pressures, adolescents tend to report that peers encourage constructive pursuits (family and peer involvement, doing well in school) to a greater extent than problem behaviors (Clasen and Brown 1985). Investigators also find that young people resemble each other on prosocial traits, although usually to a lesser extent than their resemblance regarding antisocial behavior (Haselager et al. 1998).

In more basic correlational analyses, investigators have found that young people are at lower risk for problem behavior (drug use or deviant activities) when friends have higher levels of prosocial behavior (Guo et al. 2002; Prinstein et al. 2001). Barry and Wentzel (2006) reported longitudinal evidence that friends’ levels of prosocial behavior predicted changes in prosocial behavior among a group of mid-­adolescents, especially when the friendships were characterized by high quality and frequent interaction. One peer action that may contribute to these behavior patterns is their inclination to intervene when a friend is gravitating toward deviant activity. One-third of the participants in Smart and Stoduto’s (1997) sample of Canadian youth reported that they had intervened when friends were contemplating illicit drug use or reckless (drunk) driving; one-half said they would intervene to stop a friend from smoking. Other evidence suggests that the prosocial behavior that friends display has a stronger impact on an adolescent’s activities than more direct efforts to encourage prosocial actions (Padilla-Walker and Bean 2009).

Other aspects of the peer system need to be incorporated into studies of peer influences on prosocial behavior. For example, Ellis and Zarbatany (2007) identified the peer group affiliations of a sample of Canadian youth in grades 5–8, and then calculated the status level of each peer group. Members of higher status peer groups displayed greater short-term (3-month) gains in prosocial behavior than individuals in less central groups. Potential influences of siblings also need broader consideration. Padilla-Walker et al. (2010) found that gains in prosocial behavior were directly associated with levels of sibling affection.

6 Psychosocial Assets and Adjustment

A final domain in which investigators have explored positive peer influences concerns peers’ actions that promote young people’s social adjustment or somehow mitigate circumstances that could lead to victimization or emotional maladjustment.

6.1 Bolstering Psychosocial Assets

An important way in which peers can promote positive youth development is to enhance psychological traits or social skills that are instrumental in positive adjustment. For example, Brody et al.’s (2003) longitudinal study of African American youth indicated that older sibling competence not only enhances a younger sibling’s self-regulation but also promotes higher quality parenting, both of which increase the younger child’s social competence. Aikins et al. (2005) noted that young people’s capacity to successfully navigate the transition to middle school was enhanced when they had high quality friendships. It is not clear whether the key to these patterns lies in specific actions of siblings and friends or simply the confidence that can be garnered from knowing that peer resources are available if needed.

6.2 Diminishing Emotional Distress

Existing evidence also suggests several ways in which peers may prevent or mitigate emotional distress. One way concerns the quality of peer relationships. In a longitudinal study of youth in middle childhood, Richmond et al. (2005) found that as the quality of sibling relationships improved, rates of depression diminished. Another way is through assets or resources that the relationship partner makes available. Wentzel (1998) found that the amount of social and academic support that 6th-grade students felt from peers was negatively associated with levels of emotional distress, and lower distress levels, in turn, were associated with greater academic engagement. Vance et al. (2002) reported that improvement in levels of serious emotional disturbance within a sample of high-risk adolescents was greater among those who indicated greater involvement with prosocial peers (operationalized as peers who stay out of trouble).

Social network size and structure also may be important factors. Erath et al. (2010) used a sociometric procedure to identify the number of reciprocated close and secondary friends in a sample of early adolescents. The number of reciprocated close friendships attenuated the link between loneliness and anxiety for these young people, whereas the number or reciprocated secondary friendships mitigated the negative association between social anxiety and social self-efficacy.

6.3 Protecting Against Victimization

In warding off loneliness, anxiety, or internalizing behaviors, peers diminish young people’s susceptibility to bullying or aggression because these traits are often used to target victims. Peers also appear to provide more direct protection against victimization. Some researchers have noted a protective function that peers serve. Young people whose physical attributes or emotional characteristics make them prime targets for bullying may escape victimization if they have friends, especially if these friends have the physical ability or social status to ward off peers’ aggressive actions (Fox and Boulton 2006; Hodges et al. 1997, 1999). The protective effects of friends are not always observed, however. Perceived social support from friends did not moderate the association between victimization and depression in a sample of British early adolescents (Rothon et al. 2011).

Peers also may compensate for deficiencies in other facets of young people’s social network. Schwartz et al. (2000) found that children who grew up in difficult home circumstances (e.g., exposed to harsh discipline, marital conflict, maternal hostility) later experienced higher rates of victimization by peers, but this association was mitigated by the number of reciprocated friendships they displayed – even if they engaged in relatively high rates of aggression toward peers.

As with academic achievement, peer effects on psychosocial adjustment seem to be complicated and not well evaluated. Friends seem to play bolstering and buffering roles; larger peer collectives can insulate young people from victimization that undermines adjustment. The contributions of siblings and romantic partners remain to be examined.

7 An Agenda for Research and Intervention

Peers are such a central feature of childhood and, especially, adolescence that it is not surprising to discover a growing literature documenting their significant impact on positive youth development. Yet, existing information still seems disjointed and inchoate. In an effort to encourage a more systematic exploration of peer effects, we offer four suggestions for future research.

7.1 Recommendations to Researchers

7.1.1 Moving Beyond Friendships

First, the overwhelming emphasis on friendships and friend characteristics in the studies that we located is understandable, given the centrality of this form of peer relationship to most young people. Nevertheless, examination of other aspects of the peer system must be expanded. Sibling ties and romantic relationships are especially under-represented, and studies of group (clique or crowd) dynamics can be expanded as well. Each of these types of relationships offers challenges to investigators. Romantic affiliations tend to be superficial and fleeting until mid-adolescence. Sibling analyses are complicated by issues of birth order, age differentiation, and gender composition. Peer groups are difficult to identify and track over time; they appear to be affected by the added dimensions of general peer status and group authority structure. Even friend influences may vary according to the closeness or longevity of the relationship. Greater awareness of and attention to the particularly salient dimensions of each segment of the peer system will help to clarify the conditions under which peers provide meaningful positive influences.

7.1.2 Multilevel Analyses

As a few investigators have already demonstrated, peer relationships are nested within a complex social system. Friendships and romantic relationships are shaped by the norms of peer groups in which the partners reside. A second need is for more nested designs to determine the extent to which the impact of dyadic relationships is shaped by or differentiated from group level influences. Of course, longitudinal designs are more definitive than data gathered at a single time point. A young person’s perceptions of friend or group norms may be more influential than actual group norms, but both types of data ought to be explored.

7.1.3 Emphasis on Influence Processes

Investigators have already enumerated specific processes underlying peer influences – for example, distinguishing emulation, differentiation, and example setting in sibling relationships, or exploring modeling and normative regulation in friendships. A fuller understanding of various influence mechanisms is vital to the design of effective prevention/intervention efforts because practitioners need to understand not only who fosters positive development but how they do so. We found hardly any evidence of specific processes within romantic relationships. Modulation of these influence patterns across age and across different stages of relationships also requires attention.

7.1.4 Consensus on Defining Prosocial Behavior

Finally, and more fundamentally, it would be helpful to achieve some consensus on the definition and operationalization of “prosocial behavior.” Measurement of this term varies from cataloging specific behaviors (cooperation, sharing) to identifying the absence of problematic behaviors (percentage of one’s friends who do not use drugs). These very different metrics make it difficult to compare findings across studies.

7.2 Implications for Intervention

Attempts to co-opt the peer system for the purposes of prevention/intervention or even enhancement of youth development are fraught with danger because the system is designed, especially in adolescence, to resist subjugation to adult control. There are numerous examples of iatrogenic effects in response to peer based interventions designed by adults (e.g., Dishion et al. 1999; Mahoney et al. 2001). Particularly in view of the limited research to date on positive peer effects, our three recommendations should be considered tentative.

7.2.1 Appreciate the Positive Potential of the Peer System

Although the evidence we cite is limited, it indicates remarkable potential for peers to foster positive youth development in numerous ways. Mindful of this, adults should approach the peer system from a positive perspective, seeking to harness the system to support prosocial norms and behaviors rather than attempting to impede the system’s inclination to encourage antisocial behavior. The infamous “just say no” campaign is an example of how a fundamental misunderstanding of the peer system can lead to a fatally flawed approach to prevention. On the other hand, efforts to foster prosocial group norms and supportive relationships at the dyadic level appear to be especially useful.

7.2.2 Recognize Developmental Dynamics

Just as children and youth grow and change, so do the structure and operation of their peer system. Interventions must be carefully calibrated to the developmental features of dyadic and group relationships. Close friendships take on stronger support functions in adolescence than they manifest in childhood; with age, friendship groups grow more stable. These developmental changes affect the capacities of various facets of the peer system to foster positive development and to respond to adult guidance in this mission.

7.2.3 Leave Well Enough Alone

For most young people, the peer system works effectively to promote positive development. It does not require much in the way of adult tampering. This system fosters a variety of positive outcomes, including nurturing youths’ desires to assume more responsibility for and autonomy over their affairs. In many cases, the best thing that adults can do is to simply let it be.

8 A Closing Caveat

Our mission has been to illustrate the potential of the child and adolescent peer system to foster positive development and to encourage more research from this perspective. Yet, the capacity of peers to be a destructive, health-compromising force in young people’s lives cannot be denied. The best approach to research and intervention is the most challenging: to recognize and respect peers’ capacity to enhance as well as undermine individual development. Keeping a balanced view should help adults to guide young people to more effective, rewarding relationships with their peers so that these relationships, in turn, can serve the best interests of positive youth development.