This review reveals strong and consistent sex differences in a variety of peer relationship processes. What are the implications of these sex differences for the long-term development of girls and boys? To answer this question, we propose a speculative, integrative peer-socialization model (see ). We propose that exposure to same-sex peers contributes to the development of sex-typed peer relationship processes, including peer relationships styles, stress and coping processes, and relationship provisions. Sex differences in these peer relationship processes, in turn, are hypothesized to influence girls’ and boys’ emotional and behavioral development. In essence, the model proposes that sex differences in emotional and behavioral adjustment can be partially accounted for by sex differences in peer relationship processes, which are fostered at least in part by exposure to same-sex peers.
This model can serve as an organizational framework for integrating the diverse array of findings regarding sex differences in different domains of relationship processes. We emphasize that many aspects of this model are speculative, and have not yet received substantial empirical support. Yet, we believe that it is time to progress beyond summaries of sex differences in separate areas of relationship processes to consider the implications of sex differences across multiple domains for the development of girls and boys. We hope that this model will serve to stimulate future efforts to examine links among sex differences in these various domains. As an example, following the model description, we present preliminary research from our own laboratories that substantiate components of the model. Finally, we suggest future research directions that would address important understudied aspects of the model.
This conceptualization extends previous work that summarizes and evaluates specific components of the model. Previous important commentaries on how sex differences in relationship processes influence psychological and physical health (
Cross & Madson, 1997;
Helgeson, 1994;
Nolen-Hoeksema & Girgus, 1994) focus more on the consequences of sex differences in social-cognitive or stress-related processes, and less on the
development of these sex differences. In a complementary approach, developmental research provides comprehensive descriptions of sex differences in relationship styles with peers (see
Maccoby, 1990,
1998;
Rubin et al., 1998), but focuses less on the implications of these differences for emotional and behavioral development. Integrating these diverse areas of theory and research provides a unique perspective on how the peer group may influence the developmental progression of sex-linked adjustment. Moreover, this peer-socialization model expands on prior conceptualizations of gender socialization (
Ruble & Martin, 1998) that focus largely on adult socialization agents and broader cultural influences, such as the media.
As discussed earlier, integrating across different theoretical perspectives also extends previous work by highlighting the potential trade-offs of certain sex-linked attributes that often have been overlooked. A major premise of the model is that sex-linked relationship processes lead to important trade-offs in the development of girls and boys. In particular, we propose that relationship processes characteristic of girls place them at risk for developing emotional problems, such as low self-esteem, anxiety, and depression, but also inhibit antisocial behavior. In contrast, relationship processes characteristic of boys enhance their likelihood of developing behavioral problems, such as aggression and other antisocial conduct, but also protect them against developing emotional problems.
The Role of Peer Socialization within the Broader Context of Other Socializing and Biological Influences
Our peer-socialization model proposes that exposure to same-sex peers elicits and strengthens sex-linked relationship processes, which, in turn, contribute to the development of sex-linked adjustment outcomes. In considering peer-socialization models, the question has been raised regarding whether all youth are equally effected by peer socialization or whether some youth are exposed to, and/or effected by, peer socialization more than others (
Harris, 1995,
Maccoby, 1988,
1998). Although early evidence did not indicate stable individual differences in the degree to which particular youth were immersed in same-sex peer groups, more recent research indicates that there are stable individual differences in the tendency for youth to interact with same-sex peers, at least in early childhood (
Martin & Fabes, 2001). As a result, some children are exposed to same-sex peers more than others, and presumably are socialized most strongly to adopt sex-linked characteristics.
Despite the theoretical importance of peer socialization (
Harris, 1995), research in this area is surprisingly limited. However, important recent research by
Martin and Fabes (2001) does suggest that the degree to which youth are exposed to same-sex peers contributes to how much sex-typed behavior they exhibit. Specifically, for preschool and kindergarten children, spending time with same-sex peers was found to predict increased sex-typed behavior (e.g., playing with dolls for girls and trucks for boys) over a six-month period. Other research with young children (
Fagot, 1977;
Fagot & Hagan, 1985;
Lamb & Roopnarine, 1979) and adolescents (
Hibbard & Buhrmester, 1998) indicates that youth respond most positively to peers who display sex-typed behavior. Although these latter studies do not speak directly to whether more exposure to same-sex peers predicts increasingly sex-typed behavior, the data do provide additional evidence for the role of peers as socializing agents.
In regard to our model, the implication of the
Martin and Fabes (2001) study is that youth who are exposed the most to same-sex peers should be most likely to exhibit sex-linked relationship processes, and, therefore, most at risk for developing sex-linked adjustment problems. Accordingly, knowing the degree to which individual girls or boys are exposed to same-sex peers and exhibit sex-linked relationship processes should be helpful for understanding individual differences in adjustment outcomes within girls or within boys. In addition, it is also likely that individual differences among children, such as differences in temperament or personality variables, such as gender role orientation, play a role. These differences could influence the degree to which children are exposed to same-sex peers (see
Scarr & McCartney, 1983, for a discussion of “niche-picking”) and/or the impact that same-sex peers have on children’s behavior and adjustment (for an example, see
Fabes, Shepard, Guthrie, & Martin, 1997).
Of particular interest for our purposes, however, is the utility of the model for explaining the development of average or mean-level sex differences in adjustment outcomes. Because sex segregation is so strong, the vast majority of children are exposed to same-sex peers far more than opposite-sex peers during early to middle childhood. As a result, over time, socialization by same-sex peers should contribute to mean-level sex differences in relationship processes, which, in turn, are proposed to contribute to mean-level sex differences in adjustment outcomes.
Even though the primary purpose of our speculative model is to better understand mean-level sex differences in relationship processes and adjustment outcomes, it also is important to consider youth who show sex-atypical characteristics. For example, what about the boy who displays a peer relationship style more typical of girls? We propose that the adjustment outcomes for this boy may not be identical to those of a girl who displays the same relationship style. In other words, we propose that the links between particular relationship processes and later adjustment outcomes may differ for boys and girls.
Although we argue for the importance of considering peers as socializing agents, we acknowledge that there are likely to be multiple developmental pathways to sex differences in adjustment. Comprehensive reviews discuss the roles of evolutionary forces (
Buss, 1996;
Geary, 1998), social roles (
Eagly & Wood, 1999), parent socialization (
Higgins, 1991;
Keenan & Shaw, 1997;
Zahn-Waxler, Cole, & Barrett, 1991), school contexts (
Eccles et al., 1993), personality style (
Nolen-Hoeksema & Girgus, 1994), hormonal and body image changes (
Brooks-Gunn et al., 1994;
Susman et al., 1991), and sexual and social challenges (
Nolen-Hoeksema & Girgus, 1994). We focus on the role of peers, but a number of other perspectives can be viewed as consistent with our framework.
Consider the role of other socialization figures. The shifting significance of different relationship partners should influence the relative impact of peer socialization processes at different developmental stages. In early childhood, the parent-child relationship is of primary importance. Thus, parenting practices, as well as practices engaged in by other adult caregivers (e.g., day-care providers, teachers), may play a critical role in the emergence of sex-typed characteristics during this stage.
As the salience of peer relationships increases in middle childhood (
Rubin et al., 1998), the processes described in our peer-socialization model should flourish. Importantly, peers are likely to socialize relationship styles in ways that are not redundant with the socialization influences of adults (
Harris, 1995;
Maccoby, 1990). Some socializing behaviors that elicit sex-typed relationship styles are more appropriate in the context of peer relationships than asymmetrical adult-child relationships. For example, although mutual encouragement of self-disclosure is appropriate in peer relationships, parents are likely to limit personal disclosure to their children. Likewise, competition, such as that common among boys, is more appropriate among peers than between youth and adults. Peers also may socialize sex-typed behavior in ways parents do not. Even children of parents who strive to treat them in gender-neutral ways are likely to be immersed in a sex-segregated, sex-typed peer culture (
Harris, 1995). Perhaps the increased significance of same-sex peers in middle childhood strongly activates links in the model, which helps to explain, in part, increases in sex differences in adjustment at adolescence.
Despite the likely distinct contributions of adult and same-sex peer socialization influences, sex-typed peer socialization also may be influenced by adult socialization. In fact, sex-typed peer relationship styles may have their origins in adult gender socialization. Although not all studies indicate that parents rear boys and girls differently (see
Lytton & Romney, 1991), when differences emerge, parents tend to encourage empathy, self-disclosure, and physical proximity among girls, and independence and physical competence among boys (see
Block, 1983;
Ruble & Martin, 1998;
Zahn-Waxler, 2000;
Zahn-Waxler et al., 1991). These styles, developed in the context of parent socialization, may be further socialized and reinforced by peers due to the socialization cues that children detect from adults. That is, same-sex peers may continue to socialize their peers in ways that are consistent with how they themselves are socialized by adults, thereby strengthening any pre-existing tendencies.
Notably, the processes described in the model, which are tied to same-sex peer groups, may weaken in later adolescence and early adulthood, when opposite-sex platonic and romantic relationships assume increasing importance for many individuals. As individuals spend more time with opposite-sex peers, they may adopt some aspects of relationship style more typical of the other sex (e.g., adolescent boys and men having intimate discussions with their female partners). However, sex differences in many relationship processes and adjustment outcomes are still expected among older adolescents and adults for several reasons. Some relationship processes may be so strongly consolidated by late adolescence that they are no longer effected by changes in peer reinforcement. In addition, some adjustment problems that originally stemmed from peer relationship processes may progress along on a self-perpetuating course. For example, behavioral problems among boys that were originally sparked by peer socialization may follow a developmental trajectory toward more severe problems that are no longer tied only to the peer context.
Last, although we have been focusing on the role of same-sex peers and other relationship partners as socialization agents, our model also can be viewed as consistent with biological models of sex differences. Consider, for example, the idea that sex-linked behavioral responses to stress stem from sex differences in hormonal reactions to stress (
Taylor et al., 2000; see also
Geary & Flinn, 2002). Researchers suggest that stress may induce an affiliative (“tend and befriend”) response in females due to the release of oxytocin, but an aggressive (“fight or flight”) response in males due to the release of testosterone. We view this perspective as compatible with our peer-socialization model. Biological and psychosocial forces likely act in concert to guide sex-typed stress responses. Moreover, there is growing evidence that social experiences may, in fact, influence the development of biological systems underlying behavior and emotion (
Bruer & Greenough, 2001;
Gold, Goodwin, & Chrousos, 1988).
The Role of Sex Differences in Peer Relationship Processes in Girls’ and Boys’ Emotional and Behavioral Development: A Detailed Description of the Model
Based on our summary of sex differences in behavioral and social-cognitive styles in relationships, stress and coping processes, and relationship provisions, we consider how these relationship processes might be linked with sex differences in youths’ emotional and behavioral development. In formulating predictions about emotional and behavioral development, we adopt the conventional distinction between emotional distress/internalizing symptoms versus behavioral problems/externalizing symptoms. Although considerable co-occurrence is present between these types of difficulties, empirical research consistently supports the validity of this broad distinction when characterizing adjustment in youth (e.g.,
Achenbach & Rescorla, 2001).
Further validating the distinction, a considerable amount of past research, as summarized in several integrative reviews, consistently suggests different patterns of sex differences for emotional versus behavioral problems. In particular, girls experience more emotional distress than boys, including low self-esteem, anxiety, and depression (for reviews, see
Albano & Krain, 2005;
Cyranowski, Frank, Young, & Shear, 2000;
Hankin & Abramson, 2001;
Kuehner, 2003;
Mackinaw-Koons & Vasey, 2000;
Nolen-Hoeksema & Girgus, 1994;
Ruble, Greulich, Pomerantz, & Gochberg, 1993;
Twenge & Nolen-Hoeksema, 2002;
Yonkers & Gurguis, 1995). Sex differences in some aspects of emotional distress, such as anxiety, are present in childhood. However, the strength of sex differences in emotional distress tends to increase at adolescence, particularly for depressive symptoms (
Hankin & Abramson, 2001;
Nolen-Hoeksema & Girgus, 1994;
Twenge & Nolen-Hoeksema, 2002). In contrast, boys exhibit more behavioral problems than girls, including aggression and antisocial conduct, but these differences also depend on the developmental period considered (for reviews, see
Coie & Dodge, 1998;
Foster, 2005;
Hinshaw & Anderson, 1996;
Moffit, Caspi, Rutter, & Silva, 2001;
Zahn-Waxler, 1993). Sex differences in aggression are strong throughout childhood and adolescence. However, the magnitude of sex differences in other forms of antisocial conduct, including rule violations such as truancy, substance use, and leaving home, decreases during adolescence because girls’ involvement in these behaviors increases.
In considering how relationships processes are linked with emotional and behavioral adjustment in the following description of the model, developmental stage will be taken into account. For example, we will highlight cases in which relationship processes may help explain sex differences becoming stronger or weaker with age (i.e., for depression or behavioral problems such as rule violations). For those cases in which sex-linked relationship processes are proposed to predict sex-linked adjustment throughout childhood and adolescence, developmental stage will not be referenced for parsimony.
The proposed model is considered to be speculative because there is very little research that provides direct tests of the model. At this point, the primary evidence in support of the model is circumstantial. However, the pattern of sex differences considered in the review fits with the predictions of the model. In addition, there is considerable research examining links in the model (e.g., associations between particular relationship processes and particular indexes of adjustment). In fact, the examples of these associations presented are only illustrative as these literatures are vast and beyond the scope of the present paper. We consider this research a reasonable basis for forming preliminary hypotheses about how sex-linked relationship processes may help to account for sex differences in emotional and behavioral development, but emphasize the need for research that directly tests the predictions of the model.
Peer Relationship Styles and Emotional and Behavioral Adjustment Behavioral styles The reviewed research indicates some consistent sex differences in behavioral styles with peers. These differences include girls’ greater tendency to engage in extended dyadic interactions, to engage in cooperative, prosocial behavior, and to self-disclose to friends. Moreover, studies indicate that the sex difference in self-disclosure strengthens at the transition to adolescence. The summary also points to boys’ greater tendency to interact in groups of peers characterized by high network density and a well-defined dominance hierarchy and to engage in rough-and-tumble play and competitive/organized play. In this section, we consider the implications of these sex differences for emotional and behavioral adjustment.
First, these sex differences in behavioral styles are proposed to affect the development of emotional adjustment problems. In some ways, girls’ behavioral styles may protect against the development of emotional adjustment problems. For example, being immersed in a peer group in which interactions often are characterized by cooperation and prosocial behavior should contribute to emotional well-being. The greater disclosure among girls also may have positive effects. However, these seemingly positive aspects of girls’ behavioral style may negatively impact emotional adjustment through their influence on other peer processes. For example, self-disclosure is thought to be a means by which friends can validate one another’s unique characteristics and emerging identities, which should have a positive impact on self-esteem (see
Sullivan, 1953). However, girls’ tendency to self-disclose, especially in adolescence, also may provide a context for some responses to stress (e.g., talking excessively about problems) that contribute to the development of internalizing problems. In addition, the cooperative, prosocial styles of girls’ groups may promote empathy and an awareness of the stressful experiences of peers and friends, which could negatively impact emotional well-being. Accordingly, it is not entirely clear whether the net effect of behavioral style on girls’ emotional adjustment is positive or negative. Moreover, the majority of other peer relationship processes to be discussed are thought to increase girls’ risk for emotional problems. For boys, behavioral styles are proposed to work along with the other relationship processes to buffer them against emotional problems. In particular, boys’ activity-focused styles should provide them with interesting and enjoyable experiences that should promote a positive mood (see
Gottman, 1986).
Typical sex-linked behavioral styles may have opposite influences on the behavioral adjustment of girls and boys. Because norms in girls’ peer groups call for higher levels of cooperative and prosocial behavior than those in boys’ peer groups, disruptive and aggressive behaviors among girls are more likely to be censured by peers. Further, boys are more likely than girls to acquire within their peer group the behaviors required for serious aggressive acts, such as fighting skills. These skills may be learned even in mainstream male peer groups through rough-and-tumble play among younger boys and through other organized and competitive games and sports among older boys and adolescents. Moreover, the male peer group may foster a tendency among boys to engage in aggressive, self-promoting behavior if such behavior elevates their position in the dominance hierarchy (see
Geary, Byrd-Craven, Hoard, Vigil, & Numtee, 2003).
Importantly, research is needed that directly tests whether the degree to which girls and boys differ in their behavioral styles with peers helps to account for sex differences in emotional and behavioral adjustment. Moreover, research needs to consider whether the contribution of behavioral styles to the development of adjustment outcomes varies by sex. For instance, self-disclosure may promote positive emotional adjustment in girls if friends validate each others’ perspectives. In contrast, if boys are less skilled at self-disclosing or providing validation, their conversations may not have equally positive effects.
Social-cognitive styles Several important aspects of social-cognitive styles regarding peers were found to vary by sex. Specifically, girls are more likely than boys to define themselves in terms of relationships and to care about dyadic friendships. Girls also are more likely than boys to adopt connection-oriented goals and to be empathetic, as well as to have interpersonal concerns (e.g., about evaluation) and to experience jealousy within friendships. Boys are more likely than girls to have status-oriented or agentic goals. We suggest that these sex differences in social-cognitive styles have important implications for the emotional and behavioral development of girls and boys.
Sex-linked social-cognitive styles are proposed to increase risk for the development of emotional problems in girls and to decrease risk in boys (see
Gilligan, 1982;
Helgeson, 1994). Girls’ greater concerns about evaluation and approval and investment in connection-oriented goals, are proposed to contribute to emotional problems, such as anxiety and depression. That is, girls may be more likely than boys to devote time to worrying about the status of their relationships, which may negatively influence their emotional well-being. In addition, given that girls may be particularly susceptible to feelings of jealousy within their friendships, it is plausible that they would be more likely than boys to become distressed over potential areas of discord or abandonment that never actually occur. These predicted pathways are consistent with evidence linking some of these aspects of social-cognitive styles, including fears of negative evaluation and friendship jealousy, with internalizing symptoms such as low self-worth and feelings of anxiety (
LaGreca et al., 1988;
La Greca & Lopez, 1998;
Parker et al., 2005). In contrast, boys’ decreased likelihood of adopting these social-cognitive styles should diminish their susceptibility to the development of emotional difficulties.
The links between social-cognitive styles and emotional adjustment may strengthen with age, thus contributing to the increasing sex difference in emotional difficulties over the course of adolescence. At adolescence, there are important changes in the nature of peer relationships (see
Brown, 1990;
Rubin et al., 1998), including that close dyadic friendships become especially important to youth (
Sullivan, 1953). At this time, fears of abandonment and jealousy over friends’ other relationships may become more closely tied with global feelings of distress due to the increased salience of these relationships. This distress may be reflected in increasing internalizing symptoms among girls during this stage of development.
Despite these emotional costs, female-linked social-cognitive styles should generally protect girls from developing behavioral problems. Such behaviors are inconsistent with girls’ greater inclination to define themselves in terms of close relationships and with their concerns about social judgment, which presumably would motivate them to minimize behaviors that elicit interpersonal rejection (
Rudolph & Conley, 2005). Girls’ higher levels of empathy, specifically their greater tendency to experience vicarious distress, also should suppress behaviors that cause distress to others. Nevertheless, it is possible that during adolescence, social-cognitive styles in some girls contribute to increased behavioral problems, such as rule-violating behaviors, as a result of their involvement in romantic relationships. That is, girls’ connection-oriented goals may lead them to engage in behaviors such as substance use and truancy to strengthen ties with boyfriends who behave this way (see
Caspi, Lynam, Moffitt, & Silva, 1993). Alternatively, it is possible that the girls who demonstrate increases in behavioral problems during adolescence are those whose sex-typed social-cognitive styles are diminished by their immersion in opposite-sex peer groups. For boys, typical social-cognitive styles may create risk for aggression. The status and agentic goal orientations of boys may put them at risk for aggressive behaviors directed toward the pursuit of their own self interests (
Cross & Madson, 1997;
Helgeson, 1994). Although decreased concern about social approval or getting along with others may be adaptive to some extent in terms of moving up the dominance hierarchy, at more extreme levels this lack of concern increases the chance that boys will engage in antisocial behaviors without considering the impact on others.
Some previous conceptualizations also posit that sex differences in social-cognitive style more generally (i.e., not specifically in the peer context) may contribute to sex differences in emotional and behavioral health (
Cross & Madson, 1997;
Helgeson, 1994). Moreover, evidence supports relations between some aspects of social-cognitive style and indexes of adjustment (e.g.,
LaGreca et al., 1988;
LaGreca & Lopez, 1998;
Parker et al., 2005). However, little empirical data actually test whether sex-linked social-cognitive styles mediate sex differences in emotional and behavioral adjustment. Moreover, we do not know whether the proposed links operate in the same way for girls and boys. As an example, the links between feelings of jealousy or concerns about negative evaluation and emotional distress may be stronger for girls than boys. It is possible that boys are more likely to respond to such feelings by terminating friendships or interactions with particular peers rather than by internalizing the negative feelings or by generalizing the evaluation-related concerns to their global well-being.
Stress and Coping Processes and Emotional and Behavioral Adjustment Exposure to peer stress Our summary indicates sex differences in youths’ exposure to certain types of peer stress. Specifically, girls have a greater tendency than boys to experience stress within the context of their dyadic friendships (except for being physically victimized by a friend or experiencing conflict with a best friend) and to vicariously experience stress of others in their social networks. There also is some indication that, when different types of stressful peer events are combined, girls experience higher levels of stress than boys, particularly during adolescence. The only type of peer stress that boys were found to experience more than girls was physical and direct verbal victimization. We consider here how this pattern of sex differences may contribute to vulnerability to particular adjustment difficulties in girls and boys.
Girls’ greater exposure to a wider variety of personal and vicarious stressful peer events and circumstances may contribute to their heightened vulnerability to emotional difficulties. Exposure to peer stress may lead to diminished perceptions of competence, worry and concern about one’s own or a friend’s welfare, and a sense of hopelessness, potentially placing youth at risk for emotional difficulties such as anxiety and depression (see
Rudolph, 2002). Indeed, research generally links exposure to interpersonal stress, including peer-related stress, with emotional problems, such as depression (
Gore et al., 1993;
Larson & Ham, 1993;
Rudolph et al., 2000;
Wagner & Compas, 1990). Moreover, there is some limited evidence suggesting that sex-linked exposure to peer stress mediates sex differences in emotional adjustment. Specifically, greater exposure to one’s own friendship stress (
Rudolph, 2002) and to the stressors that are experienced by a friend (
Gore et al., 1993) among girls than boys help to account for sex differences in anxiety and depression. Importantly, some evidence suggests that the tendency for girls to be exposed to more peer stress than boys is most pronounced in adolescence (
Rudolph & Hammen, 1999), which may help to explain the intensification of sex differences in internalizing problems at adolescence.
With regard to behavioral adjustment, boys’ greater exposure to overt or physical victimization may contribute to their vulnerability to developing behavioral problems such as aggression and antisocial behavior. Physical aggression is more appropriate in response to overt victimization than subtle forms of victimization. In fact, if a victim responds in an aggressive manner, the attacker might be less likely to repeat the victimization, thereby reinforcing the aggression. Research does demonstrate that overt victimization predicts increases in externalizing problems over time (
Hodges, Boivin, Vitaro, & Bukowski, 1999; c.f.,
Hodges & Perry, 1999).
As discussed, there is some limited evidence suggesting that particular peer stressors contribute to sex differences in particular indexes of adjustment (
Gore et al., 1993;
Rudolph, 2002). However, whether sex differences in a variety of peer stressors help to explain multiple indexes of emotional and behavioral adjustment is unknown. We also know relatively little about whether the effects of peer stressors on adjustment are similar for girls and boys, but some data suggest the effects may vary by sex. In particular, because girls’ social-cognitive styles involve connected-oriented goals and interpersonal concerns, peer stress may represent an especially strong threat to their emotional well-being. Girls perceive interpersonal stress in general (
Wagner & Compas, 1990) and relational or social victimization in particular (
Crick, Bigbee, & Howes, 1996;
Galen & Underwood, 1997) as more stressful or hurtful than do boys. They also report experiencing more negative emotions within peer contexts than do boys (
Larson & Asmussen, 1991). Moreover, preliminary evidence suggests that interpersonal stress in general (
Goodyer & Altham, 1991;
Rudolph & Hammen, 1999;
Rudolph et al., 2000) and peer stress in particular (
Conley & Rudolph, 2005;
Rudolph, 2002) is associated with emotional difficulties more strongly in girls than in boys. In fact, even though boys report greater overt victimization (e.g., teasing, fighting) than girls, these stressors are more strongly associated with anxiety and depression in girls (
Rudolph, 2002).
Responses to peer stress Our summary also indicates sex differences in responses to stress. Specifically, girls tend to seek support more than boys. This finding often emerged in middle childhood but was found more consistently among adolescents. Girls also ruminate and express emotions in response to stress more than boys. There was some support for the idea that boys use humor and make light of stress more frequently than do girls. How might these sex differences contribute to girls’ and boys’ development?
Sex-linked responses to peer stress may contribute to sex differences in emotional adjustment. Girls’ tendency to express emotions and seek support from peers may in part buffer them from emotional distress. By seeking support, girls may be provided with reassurance that their problems can be resolved and that they are valued members of their social group, thereby decreasing the chances that stressors will lead to decreased self-esteem, excessive worrying, sadness, or other types of emotional distress. In fact, receiving social support from peers is linked with lower levels of depressive symptoms (
Burton, Stice, & Seeley, 2004;
Licitra-Kleckler & Waas, 1993). However, this support-seeking tendency also presents a risk that girls will become fixated on talking about problems, which may increase their emotional distress. In fact, rumination about problems, including peer problems, is associated with poorer self-esteem (
Broderick, 1998). In contrast, boys’ greater likelihood of making light of problems may keep them from dwelling on problems and, therefore, be protective against emotional problems. In fact, some evidence suggests that using humor to cope is related to lower levels of anxiety and depressive symptoms over time (
Plancherel & Bologinini, 1995).
In terms of behavioral problems, we propose that responses typical of girls will be protective, whereas responses typical of boys may increase risk. Stress responses more common among girls (e.g., seeking support, rumination) are inconsistent with antisocial behaviors. In contrast, responses more typical of boys, like making light of the problems, coupled with boys’ decreased likelihood of seeking support or processing negative feelings, may foster behavioral problems. For instance, an unresolved conflict with a peer may lead to future misunderstandings and hard feelings, which may precipitate aggressive attempts to seek revenge. The latter idea is consistent with
Pollack’s (1998) proposal that, because boys do not have outlets for expressing emotions such as disappointment or hurt feelings, their emotions tend to get channeled into anger, which increases aggression. However, there is no evidence for this proposal.
Again, despite evidence of sex differences in responses to stress and some evidence for links between certain stress responses and adjustment outcomes, little research examines whether sex-linked responses to stress directly account for sex differences in adjustment. Likewise, additional evidence is needed to test whether the associations between particular responses to stress and indexes of adjustment differ for girls and boys. As an example, although support-seeking is proposed to be linked with positive emotional adjustment for girls, the effect of support-seeking may not be as positive for boys if their friends perceive their expression of emotion or requests for support as unusual or “babyish.” In fact, the effect of support-seeking on boys’ emotional adjustment may become increasingly negative with age as support-seeking becomes increasingly non-normative for boys compared to girls.
Relationship Provisions and Emotional and Behavioral Adjustment Our summary suggests that, compared to boys, middle childhood and adolescent girls generally report receiving greater provisions in their dyadic friendships such as closeness, affection, trust, security, loyalty, validation, acceptance, enhancement of worth, and nurturance. Nevertheless, boys generally report as much satisfaction in their friendships as girls. Once again, we propose that these sex differences in relationship provisions contribute to emotional and behavioral outcomes in girls and boys.
We hypothesize that receiving relationship provisions predicts more positive emotional adjustment by contributing to feelings of self-worth as a relationship partner. In fact,
Oldenburg and Kerns (1997) found that perceiving a best friendship as validating was related to lower levels of depression. Because most of these provisions typically are experienced to a greater extent by girls than by boys, girls should experience stronger provision-related protection from emotional distress than should boys. Importantly, though, these protective effects are not expected to overpower the other processes that increase risk for emotional problems in girls. Provisions are hypothesized to contribute to emotional well-being through one very specific pathway, namely, by bolstering feelings of self-worth as a close relationship partner. However, other aspects of female-linked peer relationship styles, such as concerns about general peer evaluation, exposure to peer stress, and rumination, are expected to attack girls’ emotional adjustment through a wide variety of other pathways, such as promoting feelings of worry, hopelessness, and shame. These negative emotions have broad implications for individuals’ evaluation of themselves and their life circumstances and, therefore, may be tied especially strongly to global feelings of self-worth, depression, and anxiety. Although boys may receive fewer of these provisions, those that they do receive should work along with the other relationship processes to decrease risk for emotional problems. Furthermore, boys may be receiving additional provisions in their dyadic friendships and in the peer group more generally that have not been the focus of empirical attention but do buffer them from emotional adjustment problems.
Receiving relationship provisions also is expected to decrease risk for behavioral problems. For example, provisions should contribute to feelings of relationship security and warmth toward others, which would inhibit aggression. For girls, receiving provisions such as validation and acceptance should function in conjunction with the other processes to protect them from behavioral problems. Based on current evidence for lower levels of certain relationship provisions in boys than girls, we would expect that boys would receive less protection against behavior problems than would girls. Moreover, the few types of provisions received more by boys than girls, such as greater enjoyment and excitement, may be less effective than those received by girls at inhibiting aggression toward peers and other forms of conduct problems.
As with the other relationship processes, additional research is needed to determine whether sex differences in receiving provisions help to account for sex differences in emotional and behavioral adjustment, and to determine whether the links between receiving relationship provisions and adjustment differ for girls and boys. For example, it may be that boys are less comfortable than girls with feeling strong emotions of connection with one another such as feelings of closeness, affection, and nurturance. Such discomfort could weaken the positive impact of these provisions on emotional adjustment. This might be particularly true for older boys if they perceive these feelings toward male friends as inconsistent with their emerging heterosexual identities.
Relations Among Peer Relationship Styles, Stress and Coping Processes, and Relationship Provisions Although we discuss each of the three major domains of relationship processes (relationship styles, stress and coping processes, relationship provisions) independently, it is important to note that there are likely associations among these domains. For example, boys’ tendency toward more rough-and-tumble play may increase their likelihood of experiencing peer stress in the form of physical victimization if their interactions become heated or if a good-natured initiation of rough-and-tumble play is misinterpreted. As another example, girls’ heightened empathy toward peers and their focus on communal goals may promote their engagement in prosocial behavior. Note, too, that associations among the relationship domains may be bi-directional. For instance, responses to stress common among girls, such as support seeking, may lead to the receipt of relationship provisions, such as feelings of closeness and affection, among girls. However, strong feelings of closeness and affection among girls could further strengthen their comfort with and tendency to seek support from friends.
Recent Findings in Support of the Speculative Model
In recent research, we have begun to evaluate our speculative model. Within two independent research labs, support has been obtained for many key aspects of the model across a range of studies using a variety of methodologies. First, this research demonstrates links among different domains of peer relationship processes and emotional and behavioral adjustment. More specifically, however, in contrast to most prior research, findings establish directly that sex differences in peer relationship processes at one stage of the model help to explain sex differences at other stages. Second, this research reveals that certain links among peer relationship processes and adjustment differ for girls and boys and for younger and older youth, suggesting that peer socialization effects may vary across sex and across stages of development. Third, this research supports the proposal that sex-linked relationship processes contribute to seemingly paradoxical effects on development. Although findings from prior research reveal possible positive and negative consequences of similar processes, such paradoxical effects typically are not addressed within single studies. Furthermore, single constructs have not been identified that simultaneously contribute to both positive and problematic adjustment. Recent research from our labs identifies several constructs that have such effects.
In particular, these new lines of research focus on one previously researched construct (social-evaluative concerns) and two newly developed constructs (need for approval and co-rumination). Social-evaluative concerns and need for approval are aspects of social-cognitive style that reflect a tendency to rely on close relationships as a source of self-evaluation and self-worth. Co-rumination is viewed as a response to stress. Thus, these constructs fit clearly within the major domains of relationship processes incorporated into the speculative model.
Social-Evaluative Concerns and Need for Approval One line of research investigates the socioemotional costs and benefits of social-evaluative concerns and need for approval (
Rudolph, Caldwell, & Conley, in 2005;
Rudolph & Conley, 2005). According to our speculative model, high levels of social-evaluative concerns and need for approval, hypothesized to be more characteristic of girls than of boys, are expected to have both positive and negative consequences. These attributes may create an enhanced awareness of interpersonal cues and concern about relationships, which would confer benefits in terms of behavioral styles in relationships (e.g., higher levels of prosocial behavior) and behavioral adjustment (e.g., lower levels of aggression). Yet, these attributes also may create increased vulnerability to stress or problems in peer relationships, which would have costs for emotional adjustment (e.g., higher levels of anxiety and depression).
Two studies were conducted to test these ideas. In the first study (
Rudolph & Conley, 2005), 478 youth completed measures assessing social-evaluative concerns and symptoms of depression at two assessments, separated by approximately six months. Teachers provided reports of youths’ prosocial behavior and aggression. Consistent with the prediction that sex-linked social-cognitive styles have trade-offs for development, heightened social-evaluative concerns were associated with heightened prosocial behavior and diminished aggression, as well as higher levels of emotional distress (depression), both concurrently and over time. Importantly, structural equation modeling confirmed that the sex difference in social-evaluative concerns partially accounted for the sex difference in prosocial behavior and aggression, and entirely accounted for the sex difference in depression.
In the second study (
Rudolph et al., 2005), 153 fourth through eighth graders completed measures assessing need for approval, global self-worth, anxiety, and depression. Teachers provided reports of youths’ behavioral style (i.e., prosocial and withdrawn behavior) and behavioral adjustment (i.e., aggression). Need for approval was conceptualized as the extent to which youth derive self-worth from approval by peers. Importantly, need for approval was viewed as a two-dimensional construct that incorporated positive approval-based self-appraisals (enhanced self-worth in the face of high social approval) and negative approval-based self-appraisals (diminished self-worth in the face of low social approval). We expected that need for approval would have trade-offs for development. In this case, the trade-offs were expected to depend both on the adjustment outcome of interest, as well as on the dimension of need for approval (i.e., positive versus negative). Moreover, we examined whether the links between need for approval and adjustment differed across sex and age.
In support of the trade-offs premise, we found that a need for approval had both costs and benefits for development. Specifically, positive approval-based self-appraisals were associated with more prosocial behavior, less withdrawal, and less aggression, as well as with more positive emotional adjustment (i.e., enhanced global self-worth, lower anxiety and depression). Findings for negative approval-based self-appraisals were more complex. Negative self-appraisals were associated with heightened emotional distress, especially in girls. These appraisals were differentially associated with behavioral styles and behavioral adjustment across sex and age. That is, negative self-appraisals were associated with more adaptive behavioral styles and behavioral adjustment in older youth and (nonsignificantly) in girls, but with less adaptive behavioral styles and behavioral adjustment in younger youth and in boys. It may the case that youth with more self-regulatory resources (e.g., older youth and girls) are more able to mobilize their relationship concerns in the interests of improving their relationships and inhibiting antisocial behavior than those with fewer self-regulatory resources. Thus, these results point to the importance of considering whether the proposed links in the speculative model function differently across sex and developmental stage. That is, the findings suggest that when girls possess a strong need for approval (particularly negative self-appraisals), they are more at risk than boys for emotional difficulties. In contrast, when boys and younger youth possess a strong need for approval (particularly negative self-appraisals), they are more at risk than girls and older youth for maladaptive behavioral styles and aggression.
In sum, these two studies provide strong validation for several aspects of the proposed model. First, they confirm that sex-linked social-cognitive styles have critical trade-offs for development. Specifically, they demonstrate that the same relationship process (or different dimensions of the same relationship process) may serve as a protective factor for some problems and a risk factor for other problems. Second, they show that sex-linked social-cognitive styles account for some of the observed sex differences in emotional and behavioral adjustment Third, they reveal that the same relationship process may have more intense or different consequences for girls versus boys and for younger versus older youth.
Co-Rumination A second line of research involves another recently developed construct, co-rumination, which refers to extensively discussing problems in the context of a dyadic relationship (
Rose, 2002). This process is conceptualized as a response to stress and is characterized by frequently discussing problems, mutual encouragement of discussing problems, revisiting the same problem repeatedly, speculating about causes and consequences of problems, and focusing on negative feelings. Co-rumination is more common among girls than boys, especially in adolescence, and was hypothesized to have both positive and negative consequences. Based on friendship research indicating that self-disclosure is related to relationship provisions, such as feelings of closeness, greater co-rumination among girls was expected to help account for closer friendships among girls than boys. Based on rumination research indicating that a consistent negative focus is associated with emotional distress, it was predicted that greater co-rumination among girls would also help to account for more emotional difficulties among girls than boys.
These hypotheses were first tested with 608 third-, fifth, seventh-, and ninth-grade youth who responded to a new measure of co-rumination with friends (
Rose, 2002). Other measures included a self- and friend report of friendship and self-report measures of depressive and anxiety symptoms. Results indicated that higher levels of co-rumination among girls than boys helped to account for closer friendships among girls than boys (assessed by both self and friend reports) but also for more depressive and anxiety symptoms among girls than boys.
Although the previous study was consistent with the idea that co-rumination may be a peer relationship process that has both positive and negative adjustment consequences, the study did not test the temporal ordering of the relations between co-rumination and adjustment. A second study (
Rose, Carlson, & Waller, 2005) involving approximately 1,000 third-, fifth-, seventh-, and ninth-grade youth examined the effects of co-rumination on adjustment over a period of six months. The effects of co-rumination on adjustment varied depending on youths’ sex and grade. Co-rumination predicted higher levels of depressive and anxiety symptoms over time for girls but not boys. This indicated a double risk for girls: They were both more likely than boys to co-ruminate, and the negative effects of co-rumination were most severe for them. In addition, co-rumination predicted higher levels of friendship closeness over time for adolescents but not children. Perhaps extensive conversations about troubles with friends have an especially strong impact on youths’ perceptions of their friendships with age, as peers become increasingly important relationship partners in their lives.
To summarize, this line of research also supports several aspects of the proposed model in terms of the trade-offs of sex-linked relationship processes. In the first study, the same relationship process (i.e., co-rumination) was related concurrently to friendship closeness but also problematic emotional adjustment. The second study was consistent with the idea that the same relationship process may have different consequences for girls versus boys and for younger versus older youth.
Summary of Recent Research Collectively, this research demonstrates that sex-linked social-cognitive styles and responses to stress can indeed have both positive and negative consequences for development. Paradoxical effects such as these rarely have been documented within single studies and therefore represent pivotal steps toward model validation. Moreover, the prospective analyses provide support for the hypothesized direction of influence, whereby peer relationship styles and responses to stress foster particular socioemotional consequences. Direct tests of mediation validate the contribution of sex-linked relationship processes to sex differences in adjustment. The fact that certain social-cognitive styles and responses to stress differentially predict adjustment in girls versus boys suggests interesting sex differences in the proposed links in the model. Thus, girls or boys who demonstrate relationship processes characteristic of the opposite sex will not necessarily experience the same types of adjustment outcomes. Finally, differences between younger versus older youth in some of the links implicate the need for a developmentally sensitive model that accounts for changes over time in the impact of particular relationship processes on adjustment.
Future Directions
Directly Examining Peer Socialization Research is needed that explicitly examines peer socialization of relationship processes. Research on peers as socialization agents is surprisingly limited compared to research on other socialization agents. More research is needed to address basic questions such as whether interactions with same-sex peers are related to more sex-typed relationship processes, and to examine the mechanisms through which same-sex interactions foster sex-typed relationship processes.
Employing Process-Oriented Mediational Models Much of the evidence gathered thus far for the proposed model involves studies documenting sex differences in relationship processes and studies documenting significant associations between relationships processes and adjustment. However, more sophisticated designs are needed that assess the mechanisms linking sex differences in peer relationship processes with sex differences in emotional and behavioral adjustment and that allow for process-oriented interpretations of findings. When tests of mediation are not performed, the degree to which sex differences in relationships processes contribute to sex differences in adjustment is not known.
Considering Developmental Issues Disentangling the temporal ordering among the components of the model will require prospective designs that examine directly whether relationship processes are antecedents versus consequences of sex-typed adjustment, or whether there are reciprocal associations between components of the model. Furthermore, research is needed to examine the differential role of peers as agents of socialization across different developmental stages. It also will be important to investigate more carefully whether mean-level sex differences or sex differences in the proposed links between relationship processes and adjustment vary at different stages of development. Currently, for some peer relationship processes, there are limited data for certain age groups, which limits the conclusions we can draw regarding developmental differences.
Considering Trade-Offs A pivotal, and much understudied, aspect of our model concerns the trade-offs inherent in particular sex-linked relationship processes. Contrary to many prior views of sex differences, which tend to implicate certain characteristics as either adaptive or maladaptive, we argue that some relationship processes have both costs and benefits. Progress in understanding the association between sex-linked peer relationship styles and sex-linked adjustment will require examining trade-offs within single studies. One approach would be to examine, within a single study, a number of different sex-linked relationship processes that may have trade-offs. A second approach would be to examine single constructs that are predicted to be related simultaneously to positive and negative outcomes. As described previously, we have adopted this approach in our own recent research. The constructs of social-evaluative concerns, need for approval, and co-rumination were shown to have such adjustment trade-offs. Future research may involve other new constructs or identification of adjustment trade-offs of established constructs.
Considering Nonlinear Associations In our speculative model, we focus on linear associations between relationship processes and adjustment outcomes, and virtually all research on this topic is restricted to the investigation of linear associations. However, it is possible, and even likely, that some nonlinear associations exist. That is, moderate levels of certain relationship processes may be adaptive, whereas extreme levels may become maladaptive. For example, preliminary evidence suggests that social-evaluative concerns do not predict depression at low to moderate levels, but strongly predict depression at higher levels (
Rudolph & Conley, 2005). Future research needs to investigate whether moderate levels of certain relationship processes may confer fewer costs and more benefits.
Employing Varied Methodologies Much of the supportive evidence for our model is based on self-report questionnaire methods. Thus, replicating these results with other methodologies is important. For example, more observational research is needed to document sex differences in the behavioral component of peer relationship styles. The social-cognitive component of peer relationship styles is more challenging to assess using measures other than questionnaires; however, some information- processing studies with adults support sex differences in social-cognitive processes (see
Cross & Madson, 1997). In terms of stress processes, interview methods have proven to be effective for obtaining more objective information about the nature and duration of stress exposure (
Rudolph & Hammen, 1999). Experience sampling methods (e.g., beeper or palm pilot studies) also may be useful for capturing on-line social-cognitive processes and responses to peer stress. With regard to adjustment outcomes, clinical interviews could be employed to assess emotional and behavioral problems. Lastly, biological markers, such as cortisol, are related to stress responses and other social behaviors (e.g.,
Stansbury & Gunnar, 1994); studies testing links proposed in the model would benefit from considering the biological underpinnings of these behaviors.
Importantly, developmental issues need to be taken into account with regard to these methodologies. Some methods might be appropriate for some age groups but not others. As an example, younger youth would likely not be able to handle the logistics of participating in a study employing experience sampling methods, meaning that results found with this approach could not be compared across a broad range of ages. Moreover, the same method may be more or less reliable or valid at different ages. Before definitive conclusions can be reached regarding developmental trends in sex differences, it will be important to consider possible methodological factors that may account for observed developmental differences.
Learning From Mismatches Another direction for future research will involve studying mismatches between sex and the relationship processes. Much can be learned about normative processes from deviations from the norm. In particular, studying girls who exhibit relationship processes more characteristic of boys, or boys who exhibit relationship processes more characteristic of girls, can provide further validation of the model. For example, research could examine whether girls adopt agentic and self-interest goals are particularly at risk for behavior problems, or whether depressed boys engage in stress and coping responses that are more common among girls.
Moreover, insight can be gained from studying the origins of mismatches. Based on our peer-socialization model, mismatches would be expected to result from decreased exposure to sex-typed peer groups. According to group socialization theory (
Harris, 1995), children are expected to behave in sex-typed ways most consistently when sex segregation is strong, and when same-sex in-groups and opposite-sex out-groups are formed. Perhaps mismatches result from children having greater exposure to opposite-sex peers due to parental influence or to the structure of their environment. Studying mismatches also may elucidate the contribution of forces other than peers, such as the influence of genetics, family dynamics, or other environmental factors, to relationship processes and adjustment.
Explaining Co-Occurring Adjustment Problems An additional issue to be addressed is how our model accounts for the prevalence of co-occurring adjustment problems. Although the model delineates nonoverlapping paths leading from peer relationship processes to distinct emotional versus behavioral adjustment outcomes, different types of adjustment problems often co-occur among both boys and girls (
Caron & Rutter, 1991). A comprehensive model would need to accommodate such complexities as overlapping pathways and outcomes. One important caveat in this respect concerns the multi-determined nature of the processes and outcomes of interest. Relationship processes, as well as emotional and behavioral adjustment, are likely to be influenced by a wide variety of factors. These multiple factors may lead to the co-occurrence of problems that stem from different sources. For example, boys may be more likely to develop behavioral problems due to the proposed sequence of relationship processes. Yet, a subset of aggressive boys also may possess a vulnerability to emotional distress due to genetic or other environmental contributions.
Transactional influences also may help to explain the high co-occurrence of emotional and behavioral problems. For instance, peer relationship processes among boys may lead first to behavioral problems. Behavioral problems may then create difficulties in multiple domains, including school and family, and lead to negative feedback from adults. As more life domains become problematic for boys, they may begin to feel hopeless and depressed. Similarly, emotional distress in girls may interfere with school adjustment, leading to behavioral problems such as truancy or disruptive conduct. The proposal, then, is that sex-linked peer relationship processes do increase the likelihood of particular sex-linked adjustment problems, but other influences interact with these processes to create more complex developmental pathways.
The publisher's final edited version of this article is available at 
