Abstract
Peer influence is a twofold process that entails a behavior by an agent of influence that elicits conformity from the target of influence. Susceptibility describes the likelihood that conformity will occur. This review focuses on factors that shape susceptibility to peer influence. We argue that conformity has two distinct sources. In some instances, conformity is a product of characteristics of the target of influence, operationalized as stable individual difference variables. Trait-like attributes associated with susceptibility to peer influence include conformity dispositions, social goals, resource acquisition strategies, vulnerabilities, and maturational status. In other instances, conformity is a product of the context in which the target is situated, operationalized as impermanent individual difference variables. State-like circumstances associated with susceptibility to peer influence include conditions of uncertainty, personal attributes that differ from the partner or group, perceived benefits of impression management, unmet social needs, and social referents and beliefs about their behavior. Empirical illustrations are provided. We close with a discussion of developmental changes hypothesized to impact variations in susceptibility to peer influence.
Herein, we tackle the problem of susceptibility to peers. We call it a problem because, for a construct that has considerable currency among scholars, practitioners, public health experts, and parents, there is remarkably little agreement as to its meaning and measurement. What does it mean to be susceptible to peer influence? According to the Cambridge English Dictionary, the term susceptible means “easily influenced or harmed by something.” Based on this definition, one might reasonably conclude that a child who is susceptible to peer influence is easily swayed by friends and affiliates. A careful reading of the literature, however, suggests that susceptibility carries a somewhat different meaning in the field of peer relations. Typically, the focus is not on the ease with which one is swayed but rather the likelihood that one will be swayed. It is an important, if subtle, distinction. To say that a child is easily influenced implies that minimal effort is required on the part of a peer to alter the child’s behavior. To say that a child is likely to be influenced implies that that there is an elevated probability that a peer will alter the child’s behavior. The former focuses on the level of effort required by a peer to influence the child, whereas the latter describes the likelihood that an influence attempt will succeed, assuming a fixed level of effort by a peer. In other words, one definition concerns the behavior of the agent of influence and the other focuses on the receptiveness of the target of influence.
In our view, susceptibility is best defined in behavioral terms. To be susceptible to peer influence is to conform in response to the behaviors of peers. To reason backward, if one has been influenced by a peer or peer group, then one was, by definition, susceptible to peer influence. Note the flip side: If one was not influenced by a peer or peer group, then one was resistant (or oblivious) to peer influence opportunities or attempts. It is logical to assume that susceptibility refers to openness to influence from peers, but openness is not readily observable and ultimately must need be operationalized in terms of conformity behaviors.
We begin with an overview of the construct of peer influence, with the goal of differentiating the contributions of the agent of influence from those of the target of influence. The purpose is to move away from generic notions of peer influence, which typically fail to distinguish being influential from being susceptible to influence. Next, we summarize conceptual models of susceptibility to peer influence, providing empirical illustrations where possible. Our selective review highlights frameworks that emphasize trait-like attributes associated with susceptibility, as well as those that focus on transitory states that increase the likelihood of conformity. We close with a discussion of developmental changes hypothesized to impact variations in susceptibility to peer influence.
An Overview of Peer Influence
In previous papers, we defined peer influence as acting or thinking in ways that one might not otherwise act or think, in response to experiences with friends and affiliates (Laursen, 2018). This definition builds on germinal work defining peer influence in terms of changes made by relationship partners that increase their similarity (Kandel, 1978). Our definition is more expansive in that it includes the maintenance of similarity, not just increases in similarity. Maintenance is an important form of peer influence because once partners or groups attain a high level of similarity, more is not practical and entropy pressures threaten to undermine resemblances. Also worth noting is that our definition encompasses responses to disliked or out-group others that promote solidarity and, as a byproduct, heighten similarity with liked partners and in-group members. Neither of these forms of influence is readily or commonly measured; influence is usually operationalized in terms of increases in similarity.
Peer influence is observed when one or more persons affect the behavior of same-cohort others. Peer influence is a two-step process involving at least two individuals. In the first step, someone (or some group members) does something observed by or reported to peers. That something may be to model a behavior (drinking chai) or an appearance (dyed hair) or extol the virtues of a behavior or appearance, perhaps even going so far as to issue conformity directives. Alternatively, someone (or some group members) may reward demonstrations of conformity and/or punish displays of nonconformity. The mechanisms whereby influence is exerted are legion and will not be reviewed here. Instead, our point is that the first step involves an actor who is the agent of influence. Actors may be individuals or collectives; specific peers or peer groups are the agents of peer influence. The agent is responsible for the initial behavior that shapes others. That initial behavior is the source or the basis of influence. The second step involves a conformity response. In most cases, conformity involves change to resemble the agent of influence, thereby increasing similarity. In a nutshell, influence involves a behavior on the part of an agent that elicits conformity from a target.
Intentionality is not assumed. To be sure, agents often behave in ways that are consciously designed to change the behaviors of friends and affiliates. But agent intentionality is not a requirement for peer influence. Agents may be motivated by goals unrelated to shaping peers, knowing (or suspecting) that their behaviors may nevertheless alter how others act or think. Or peer influence may be an unexpected byproduct of agent actions. Sometimes agents are unaware of the effect their behavior has on others. Intentionality on the part of the target should not be assumed either. Conformity motives may be overt, designed to please or appease agents of influence, but we suspect that responses that enhance or maintain similarity are often a product of unrelated motives. Styles and habits sweep through a peer group, as do goals and values; some are adopted on their merits or for reasons of visibility. The motives for change may not be conformity, but the end result is increased similarity. Some conformity responses do not reflect reasoned action. Mere exposure can enhance attraction (Zajonc, 1968), which can unwittingly motivate conformity.
Note the implications of the two-step definition of peer influence. Action is required by both the agent and the target. Behaviors intended to elicit conformity that do not succeed should not be described as peer influence; they should instead be labeled unsuccessful influence attempts. Similarly, conformity cannot occur in the absence of an agent doing something that the target conforms to; serendipitous increases in similarity are not influence. The latter is often overlooked. Within a peer group, participants may adopt normative, age- or group-specific behaviors that spuriously increase similarity between partners in ways that resemble influence (e.g., most adolescents experiment with alcohol), a process known as stereotype accuracy (Cronbach, 1955) or cohort similarity (Hafen et al., 2011). We acknowledge that the adoption of aspirational goals or trends need not be tied to the behavior of a specific other to effect change. But deciding to become fit because physical activity goals are currently unattainable is not an example of peer influence unless those physical activity goals are modeled on or informed by specific peers. The decision to become fit may be a product of assumptions about the abilities of generalized others or information about descriptive cohort norms or averages, a process that illustrates conformity but not peer influence, because the latter requires a specific individual or group serving as an agent displaying behaviors that motivate change. Some will disagree with this distinction, but we think that when the source of perceived norms and beliefs cannot be traced to specific peers, then peers do not deserve credit for exerting influence. To wit, some youth drink to excess because they believe that generic, unspecified popular peers frequently do (Helms et al., 2014). Such findings illustrate the power of peer-group norm beliefs, but such beliefs are not necessarily evidence of peer influence, unless their source is information provided by or observations of specific peers.
It follows that to understand peer influence, we must understand the characteristics and behaviors that make agents influential, and the characteristics and behaviors that make targets susceptible to influence. As noted above, influence requires that an agent behave in ways that elicits conformity from a target. Doing so means that when peer influence occurs, it can be traced to the behaviors or characteristics of the agent, the behaviors and characteristics of the target, or (most likely) some combination of both. When we say that someone is influential, we are saying that the agent of influence behaves in ways that affects others or holds characteristics that enable them to promote change in the recipient. If influence is exclusively a product of an agent who is influential then we assume that most targets exposed to that agent will conform, becoming more similar to the agent in the process. When we say that someone is susceptible to influence, we are saying that the target is in a circumstance or possesses characteristics that make them vulnerable to change as a result of interactions with an agent of influence. If influence is exclusively a product of a susceptible target, then we assume that almost any agent can influence the target, eliciting conformity that promotes similarity. Put this way, it seems obvious that it is uncommon for influence to stem exclusively from being influential or from being susceptible. We suspect that future scholars will document that most influence is a product of a complex interplay between the behaviors and characteristics of agents, targets, and (often) circumstances.
Failure to identify mechanisms of peer influence and disentangle their sources is not a problem if the goal is simply to identify the presence of peer influence. Yet, we agree with those who argue that peer influence is so well established that it is time to move beyond documenting evidence of its existence and expand our focus to better understand sources of its variability (McGloin & Thomas, 2019). What is responsible for individual differences in susceptibility to peer influence? To appreciate the ramifications of peer influence and to devise interventions that counteract its ill effects and promote its positive effects, we need to know when and why the primary impetus for conformity lay with the target of influence, because conformity motivated by threats or rewards is very different from conformity motivated by insecurity or idolization.
We raise here an important aside. Although our definition of susceptibility is neutral with respect to valence, our discussion will, at times, necessarily reflect the field’s bias in characterizing susceptibility as a negative force. No doubt the bias is obvious to non-Western consumers of the literature, particularly for those familiar with cultures where conformity is viewed as adaptive and normative. Overwhelmingly, conceptual models and empirical research characterize susceptibility in terms of detrimental behaviors, conflating the notion of being susceptible with the tendency to engage in maladaptive practices. We do not share this one-sided view of susceptibility. To be clear, we make no claims that susceptibility is uniformly bad, nor do we mean to imply that conformity is something that ought to be always avoided. There are certainly instances when susceptibility is adaptive and where conformity is a positive force for development. Put simply, we urge readers to challenge the negative connotations attached to the term susceptibility and to recognize the beneficial components that accompany conformity.
Conceptual Models of Susceptibility to Peer Influence
The following selective summary of models of susceptibility is, in fact, a selective summary of models of peer influence that include explanations as to why targets of influence conform. These models are not typically labeled susceptibility models; most focus on other aspects of peer influence aside from conformity motives. Space constraints do not permit us to provide details on all models, and models that offer insight into susceptibility have undoubtedly been overlooked.
In the following, we divide conceptual models of susceptibility according to the time-honored distinction of states versus traits (Eysenck, 1983). Traits are defined as enduring, endogenous individual characteristics that are stable over time and across settings. Traits are often discussed in the context of inter-individual variability. Traits can and do change with development, but they do so slowly and typically with rank-order consistency. States are defined as transitory individual attributes and behaviors specific to time and place. States are often discussed in the context of intra-individual variability. Settings that elicit particular states are known to vary with age, but states themselves are not generally considered a developmental phenomenon. The borders between traits and states are fuzzy; we adopt the division for heuristic purposes, with the goal of organizing explanations into camps that emphasize conformity behaviors that reflect enduring properties of individuals and those that characterize conformity behaviors tied to circumstance.
Some conceptual models of peer influence ascribe susceptibility to immutable or slow-to-change trait-like attributes of the target, operationalized as stable individual difference variables that predict conformity behavior. Temperament, biological/neurological maturational status, appearance, ability, and identity are all examples of trait-like constructs invoked to explain susceptibility to peer influence. Other conceptual models of peer influence ascribe susceptibility to context-specific states of the target, operationalized as impermanent individual difference variables that predict conformity behavior. Partner’s social status, level of ability/expertise relative to partner or group, reference group norms, unfamiliar settings, and novel opportunities are all examples of state-like constructs invoked to explain susceptibility to peer influence. An example may prove helpful. When driving in the company of peers (an influence affordance), adolescents are more inclined to risk-taking behaviors than are adults (Chein et al., 2011), illustrating developmental, trait-like (i.e., cognitive and neurological maturity) differences. Among adolescents, there are reliable intra-individual differences that illustrate state-like differences in risk-taking while driving in the company of peers. In one case, adolescents drive faster and with less headway in the company of male passengers compared to female passengers (Simons-Morton et al., 2005). Similarly, in vehicles with adolescent drivers, seat belt use is inversely related to passenger age, and it tends to decrease as the number of passengers increase (Williams & Shabanova, 2002). (It is worth noting that not everyone agrees that risk-taking illustrates susceptibility to peer influence, a point that we will take up later.)
Illustrative Examples of State Models of Susceptibility
Table 1 summarizes conceptual models that attribute susceptibility to context- or situation-specific circumstances and states. Empirical examples of each are provided.
Summary Table of State Models of Susceptibility to Peer Influence.
Conditions of Uncertainty
Conditional vulnerability can be context-specific. With no prior experience to inform decisions and no scripts to fall back on, novel situations foster uncertainty as to how one should behave. The taste uncertainty principle asserts that when individuals are uncertain about how to respond to a novel stimulus, they rely on social information to glean the preferences of others, then shift their initial taste preference response to resemble those of companions (Moutoussis et al., 2016). Consider the first time a young adolescent attends a dinner where sushi is available. Should she partake? Uncertainty will drive her to seek input from others. Directives, information, and guidance are one avenue whereby companions can exert influence; here, conformity entails adopting the advice or instructions offered. Modeling is perhaps more common, with conformity the product of emulation. Under conditions of uncertainty, input from any source is welcome, but in these circumstances, guidance from peers is more germane than that from adults (Arriaga & Foshee, 2004), and the behavior of more similar peers is given greater weight than that of less similar peers on the assumption that those one identifies with share similar values and priorities (Laursen, 2017). Transitions represent a special form of uncertainty because they render previous scripts and self-definitions irrelevant. Moving to a new school or neighborhood upends a child’s social status, reference group, and aspects of identity, eliminating resources that might otherwise inform decisions. Even the prospect of uncertainty should promote conformity. Much as fish move through unfamiliar waters in tightly packed schools, children may prefer conformity in the face of anticipated transitions, reducing the potential risks attached to being an outlier.
Perceived pressures to conform may arise from injunctive norms (i.e., perception of what behaviors others approve or disapprove of) and from descriptive norms (i.e., perceptions of what others do) (Cialdini et al., 1991). The earliest conformity experiments illustrate how unspoken rules and descriptive norms govern behavior; in novel situations, most adults altered their stated perceptual estimates to align with peer responses (Asch, 1956). Similar findings were reported with children (Costanzo & Shaw, 1966). Relatedly, children tend to embrace new labels adopted by the majority and conform their own usage accordingly, distancing themselves from the minority (Large et al., 2019). Confronting conditions of uncertainty or when holding ambivalent views, individuals tend to adhere to perceived descriptive norms (Cialdini & Goldstein, 2004). For instance, adolescents who lacked fixed views on cannabis were more likely than others to reference friend behaviors as influential when later given an opportunity to partake (Hohman et al., 2014). Experimental findings from an unfamiliar gambling paradigm suggest that adolescents are also swayed by perceived social norms in conditions of uncertainty. The amount and type of wager placed conformed to expectations conveyed by anonymous peers (Van Hoorn et al., 2017). Informational influence may also be at work, a process whereby conformity to descriptive norms during periods of uncertainty provides an opportunity to experiment and develop opinions and preferences (Deutsch & Gerard, 1955).
Relative Attributes
Traits may be stable, but their magnitude in comparison with different peers is not. The fastest sprinter in town may be relatively slow compared to others in the county; a skilled programmer who joins a new peer group may find that her talents are now inferior to that displayed by friends. These examples illustrate how attribute significance can vary as a function of reference points. Having relatively less of an attribute that accords influence may heighten vulnerability to influence attempts. Someone who is less knowledgeable or skilled is inclined to acquiesce to the dictates of someone with more expertise or ability on the grounds that one cannot argue with success. Someone less articulate or persuasive may succumb to the verbal skills of a more adept partner. Those desirous or envious of an attribute may emulate the behaviors of those perceived to be accomplished. Finally, having relatively more of an attribute that is a source of vulnerability may increase susceptibility to influence. Less popular individuals may fear a loss of status derived from basking in the reflective glory of their more popular friends (Cialdini & Richardson, 1980). Those who are less adept in school may conform to the demands of more successful classmates whose assistance they have grown dependent on. Smaller, weaker children may acquiesce in the face of threats from more dominant partners.
Longitudinal studies consistently demonstrate that influence differs between partners as a function of relative levels of an attribute. Common are studies that identify differences in relative peer status, with higher status friends influencing their lower status counterparts over behaviors, such as weapon carrying, alcohol consumption, and marijuana use (e.g., Bot et al., 2005; Dijkstra et al., 2010; Tucker et al., 2014). Most of these studies are agnostic on the question of whether influence is a product of heightened susceptibility or heightened abilities to influence. For example, one early study found that higher status adolescents influence relatively lower status friends on delinquency and alcohol misuse, such that lower status partners change to resemble higher status partners but not the reverse (Laursen et al., 2012). New social network findings, reported in the current special section (DeLay et al., 2022), are important because they confirm that earlier dyadic findings are a product of susceptibility on the part of the lower status friend, rather than influence on the part of the higher status friends.
Another dyadic study found that relatively higher status children influenced the math achievement of their lower status friends (DeLay, Laursen, Kiuru, et al., 2016). This study was unique because although it did not distinguish variance due to being influential from variance due to susceptibility, it did identify attributes that heightened susceptibility among the lower status partner. In this case, interest in math increased conformity among those who were susceptible to friend influence by virtue of their relatively lower status. In a related example, adolescents who reported relatively more school burnout influenced the school engagement of friends who reported relatively less school burnout, but only if the latter were not close to their mothers (Marion et al., 2014). Here, weak family ties heightened susceptibility among those vulnerable to friend influence. Research also supports the assertion that influenced is a product of relative aptitude. Several studies indicate that higher performing children influence the academic achievement of their lower performing friends, and not the reverse (e.g., DeLay et al., 2015, 2021), but only one addressed the source of inter-individual variance: Conformity was strongest when lesser achieving friends who were confident about their ability to learn were paired with higher ability partners (DeLay et al., 2014).
Impression Management
Individuals care about their reputations and the views others hold about them. Impression management describes attempts to control how one is perceived. Individuals often juggle multiple facets of their reputation; the salience of the various attributes may vary depending on who they are trying to impress. Youth dissatisfied with their reputation may take steps to alter the way others see them. Impression formation often stands apart from reputation management. It is easier to manage impressions in new situations or with new affiliates—when reputations are not fixed—than it is to change minds about known entities (Leary & Kowalski, 1990). But even when one is known, one’s reputation is not unalterable. One strategy for amending a reputation is to adopt the behaviors of current affiliates or of aspirational affiliates, thus changing the perceptions of others and confirming ready-made reputational labels. A self-fulfilling prophecy may ensue, as additional behaviors and attitudes are adopted consistent with the new reputational label (Dishion & Dodge, 2006). Bottom line: Those dissatisfied with their reputations, those seeking to adopt a new reputation, and those seeking to make a good impression may all be vulnerable to suasion, particularly from those one is seeking to impress and from those who are apt to make one look especially good.
Behavioral change motivated by target impression management is evident in the eating behaviors and physical activity of children and adolescents. Longitudinal findings indicate that overweight children adjust their food consumption and exercise as a function of the social context, eating less, and biking more in the company of peers than when alone (Salvy et al., 2007, 2009). Effects are particularly strong when in the company of non-overweight peers, lending credibility to the notion that children alter their behaviors in an attempt to manage the views of those who are perceived to have a more socially acceptable body shape (Salvy et al., 2008). Here, changes in behavior do not necessarily indicate increases in similarity to behaviors exhibited by specific peers but rather conformity to assumptions about their expectations. In labeling this influence, we assume, but do not know, that behavioral change among overweight children is modeled on behaviors observed among non-overweight peers or on the desire to attain the appearance of non-overweight peers. Other evidence comes in the form of behavioral changes associated with the management of impression among new or prospective friends. Cigarette smoking conformity is evident among adolescents who seek to gain entry into a desired peer group (Aloise-Young et al., 1994); susceptibility to best friend influence over smoking was greatest for adolescents seeking admission into a peer group that included their best friend. Older, but not younger children, also display self-presentation concerns when it comes to sharing (Buhrmester et al., 1992). Compared with primary and preschool-aged children, adolescents shared more with friends, particularly when the amount shared was publicly known. Although these results do not address susceptibility per se, they illustrate that adolescents want their friends to know (and presumably appreciate) how their behavior conforms to normative expectations about preference toward friends and reciprocity within friendships.
Unmet Social Needs
Humans are social animals, with interpersonal requirements that some have described as a need to belong (Baumeister & Leary, 1995). All humans desire some social contact, although there are individual differences in the number and frequency of these contacts as well as in the perceptions about what is required to meet social needs. Unmet needs, such as the need for integration and alliance with a peer group, lead to loneliness, a state that motivates individuals to change their social circumstances (Laursen & Hartl, 2013). Conformity may be an adaptive response to perceived social isolation, a strategy designed to increase connections (or minimize distance) with others. Perceptions of social needs fluctuate with circumstances. New circumstances often trigger a desire for social contact. Partly, this is because some new circumstances are better navigated with benefit of social contact. Other circumstances trigger a reckoning, forcing the individual to compare existing levels of social support with that afforded to others; unfavorable comparisons may motivate change. Still other circumstances may throw a harsh light on the discrepancy between ideal and existing levels of social contact. Discrepancies may trigger cognitive dissonance, which can motivate the individual to take steps to enhance social contact (Bukowski et al., 2008). Each of these circumstances can elicit conformity behavior: Being perceived as amenable and compatible is an excellent strategy for building friendships and entering social groups.
Research has identified two forms of social needs that may increase adolescent conformity: (a) Being liked by others and (b) belonging to and being accepted by a peer group. It follows that peer difficulties (some of which are stable and trait-like) may elevate susceptibility insofar as they trigger unmet belonging needs, damage self-esteem, and elevate social anxiety. Some evidence supports this view. Socially anxious adolescents (particularly girls) report that their depressive symptoms change over time to resemble their partners, such that those who feared negative evaluations and sought acceptance by peers were most likely to conform (Prinstein, 2007). Similarly, adolescents who were dissatisfied (relative to their partner) with the quality of their friendship altered their alcohol consumption and truancy to resemble their more satisfied partners (Hiatt et al., 2017). Both findings are consistent with marital research (e.g., Leonard & Mudar, 2004) suggesting that unhappy partners strive to improve their compatibility to bolster relationship quality.
Beliefs about Reference Groups
Conformity behaviors are often a product of subjective views of peer behavior. The peers with whom one identifies and compares oneself to serve as reference points. References are not fixed; children move between friends and peer groups with some frequency (Kindermann & Gest, 2018), which is why beliefs about reference groups may be considered states. The degree to which one is susceptible to peer influence varies depending on the reference point that one uses and the discrepancy between the self and the referenced other. Peer groups may have explicit injunctive norms (i.e., perceptions of what is approved or disapproved by others) and standards of behavior, some of which are overtly monitored by group members, typically higher status members of the group. Many norms, however, are not explicit, but rather are open to interpretation, with the possibility that others may hold different views. They are, in a word, subjective and (we suspect) fluid. Either way, susceptibility may well be motivated by psychological tension arising from the perceived gap between norms and individual behavior (Cohen & Prinstein, 2006). The process may be planful: Reasoned action theory (Fishbein & Ajzen, 2010) holds that individuals focus explicitly on referenced peers, who serve as guides for future behavior. Others note the need to recognize spontaneous reactions to social opportunities arising in interactions with reference group members (Gibbons et al., 2008). Popular peers are a prototypical example of leaders who serve as references; conformity flows from beliefs about what specific high-status others are thought to do or are thought to want others to do. Aspirational leaders may have talents or attributes that one wishes to emulate; conformity behaviors may hew closely to what is modeled by domain-specific influencers. The state-like nature of the process is underscored by the fact that individuals shift aspirational references. Consider a novice chess player who first compares herself to other novices, but as her skills grow, alters her reference point (and commensurate behaviors) to be consistent with those who have greater expertise.
It follows that low-status members of the group are susceptible to influence from high-status members, who serve as points of reference that group members use to guide behavior. Put simply, group members conform to the demands and expectations of group leaders. Note that here we describe absolute, not relative levels of status; the latter describes the self in relation to a specific individual, the former describes the self with regard to the reference group. Experimental evidence is consistent with the view that low-status individuals look to high-status individuals to guide beliefs and behaviors. For instance, adolescents revise their initial views about health-risk, deviant, and aggressive behaviors to better align with the views of a high-status peer (Cohen & Prinstein, 2006; Prinstein et al., 2011). Similarly, adolescents reporting the greatest increase in sexual partners were those who previously reported that high-status peers were engaged in risky sexual behaviors (Choukas-Bradley et al., 2014). Similar findings emerged for susceptibility to influence over positive behaviors. In one study, adolescents demonstrated greater conformity to the perceived prosocial intentions of high-status peers than to the intentions of lower or average status peers (Choukas-Bradley et al., 2015). Finally, there is evidence to suggest that adolescents are also swayed by shifts in visible behaviors among significant portions of the peer group. Interventions suggest that changing the public behavior of a critical mass of randomly selected members of a reference group is an effective strategy for altering attitudes about harassment in school, which, in turn, reduced harassment behaviors (Paluck & Shepherd, 2012).
New circumstances, such as those encountered by first-year university students, are states that elicit conformity. There is evidence that injunctive norms shape alcohol consumption in these circumstances, such that drinking behaviors align with the concurrent perceived norms of friends and with the norms of the peer group, particularly for those who strongly identify with the group (Neighbors et al., 2008, 2010). Longitudinal evidence points toward a similar conclusion during adolescence; greater group identity predicted greater conformity to group delinquency norms (Kiesner et al., 2002). Similarly, the weight-control behaviors of adolescent girls varied as a function of the behaviors of other similar-weight girls in the school; both underweight and overweight girls reported weight-control activities that mimicked those of their same-weight counterparts (Mueller et al., 2010).
Illustrative Examples of Trait Models of Susceptibility
Table 2 summarizes conceptual models that attribute susceptibility to stable trait-like individual tendencies. Empirical examples of each are provided.
Summary Table of Trait Models of Susceptibility to Peer Influence.
Conformity Dispositions
Some have postulated a trait-like tendency best described as willingness to conform, which encompasses being open to influence and eager to please others (Brown et al., 2008). Conformity dispositions are integral to the behavioral intention model, which holds that the more one is oriented to or preoccupied with pleasing others, the more susceptible one is to influence (Ajzen & Fishbein, 1970). In addition to models that identify conformity as a trait, other models specify traits with ancillary correlates that include a heightened vulnerability to influence. Personality traits may elevate susceptibility (Laursen, 2018). Agreeable individuals may prefer conformity to confrontation; conscientious individuals may have a heightened awareness to norms and respect for authority, which may make them scrupulous about adhering to them. Individuals also vary in terms of whose views they prioritize, tying susceptibility to sources of influence. Youth with an extreme peer orientation purportedly place a heightened emphasis on the views of peers, with little or no weight given to the views of parents or adults (Fuligni & Eccles, 1993). Those holding this orientation are not generally susceptible to influence, except that exercised by peers.
Conformity dispositions can be measured with self-report surveys that assess the trait-like tendency to be influenced by peers. One frequently used self-report survey assesses susceptibility to peer influence in neutral situations, without reference to antisocial or risky behaviors (Steinberg & Monahan, 2007). The measure has been linked to non-planning impulsivity, which reflects low self-control and low interest in planning for the future (Cavalca et al., 2013). High self-reported peer susceptibility has been linked to a host of risk-taking behaviors (e.g., Ahmed et al., 2020; Telzer et al., 2021) as well as to elevated prosocial behavior (McConchie et al., 2022). Another self-report index, extreme peer orientation, has been tied to self-reported willingness to accept alcohol when offered by friends and other peers (Jackson et al., 2014). A different strategy to assess conformity dispositions involves an experimental paradigm that assays an individual’s tendency to change responses to resemble those of peers. These indices of susceptibility also find that higher levels of trait susceptibility are linked to higher levels of conformity to friend behaviors (Prinstein et al., 2011). The present special section includes a new experimental index of conformity (Duell et al., 2020) that yields similar findings: Adolescents with high levels of assessed conformity were most likely to change their alcohol use over time to resemble that of friends. Finally, some studies posit a trait-like characteristic of opportunity openness, roughly defined as a willingness to engage in a behavior (e.g., consume alcohol), should someone (typically, but not necessarily, a peer) provide the possibility to do so (Gibbons et al., 2004). Here, the trait in question is not openness to peer influence, but rather a willingness to engage in a specific behavior should a peer provide an affordance for that behavior.
Certain traits may amplify tendencies to conform. Self-monitoring appears to be an important component of the conformity disposition. High self-monitoring individuals attend to social cues about inferred normative behaviors, then eventually adopt those behaviors (Perrine & Aloise-Young, 2004). Self-control also exacerbates conformity tendencies (Meldrum et al., 2013). Perhaps, the study that most clearly ties traits to susceptibility is one where peer deviance predicted increases in adolescent delinquent behavior for youth low on parent-reported task orientation, flexibility, and positive mood (Mrug et al., 2012). Similarly, longitudinal associations between self and friend delinquent behaviors vary as a function of conscientiousness (Slagt et al., 2015). Finally, it is worth noting that positive traits may encourage conformity. Individuals who are eager to learn or acquire expertise may be particularly open to input from others. For example, children who enjoy academic pursuits are likely to adopt new academic behaviors, especially those who belong to a group whose members tend to do well in school (Masland & Lease, 2013).
Resource Acquisition Strategies
According to resource control theory, individuals actively strategize about how to best acquire social and physical resources (Hawley, 1999). The theory focuses on social dominance, but buried within is the kernel of an idea that is relevant to susceptibility. We suspect that some children determine that they cannot acquire resources through dominance, but may instead attempt to gain resources by appeasing dominant others, ingratiating themselves into the company of the powerful by acquiescing to demands. Early on, the powerful directly bestow resources on less powerful affiliates. In time, however, affiliation with the socially dominant should increase one’s own status, enhancing the ability to acquire resources outright. The model implies a deliberate strategy of growing and staying close to those with resources. Conformity can assist in achieving closeness with and securing resources from the powerful. Dominant affiliates may change as power shifts and resource goals are revised, leading to outward changes in behavior, but the overall tactic of strategically conforming to the powerful is apt to be consistent over time.
Membership in a high-status group is especially attractive to low-status adolescents seeking social relevance and resources (Eder, 1985). We know that low-status youth are more apt to conform to peers than are their higher status counterparts (e.g., Rambaran et al., 2013; Shi & Xie, 2012). We also know that low-status adolescents gain prominence and become more popular as a result of affiliation with high-status companions (Dijkstra et al., 2013). Thus, it is not surprising that peripheral members of the group are most susceptible to the spread of behaviors from central members (Conway et al., 2011). However, despite reports that children strategically behave in ways designed to enhance status (Hawley & Bower, 2018), there is no evidence to date that these strategic behaviors include conformity to high-status members of the group.
Vulnerabilities and Liabilities
Susceptibility to influence may flow from perceived or actual weakness and failure. Repeated failed attempts to get one’s way may teach children the futility of resistance (Rholes et al., 1980). Submission may become an acquired habit, akin to learned helplessness. Discrimination may also instill a sense of helplessness, because it creates powerful obstacles to success. The disadvantaged may rarely prevail against the powerful, meaning that the latter are, by definition, susceptible. In time, children may learn that discrimination creates long odds for success, instilling resignation and conformity, even in situations where successful opposition may be possible. Conversely, high levels of self-blame may also increase susceptibility, because individuals assume that adverse consequences for failure to conform can be remedied by behavioral corrections (Costanzo, 1970). Other attributes may similarly limit resistance to influence attempts. Those who perceive themselves to be (or know their reputation to be) unattractive, unintelligent, or unathletic may generalize from persistent failure in these domains, eventually concluding that they are unlikely to prevail in most domains. Low self-esteem is the putative mechanism (van Zalk & van Zalk, 2015), which has origins in a host of other challenges besides those mentioned here. Low self-esteem is assumed to undermine self-efficacy, sowing doubt about one’s abilities and the worthiness of one’s goals, increasing passivity and susceptibility through reduced persistence and diminished or unconvincing effort. Depression, anxiety, and timidity may elicit conformity for similar reasons. Note that the tendency to engage in social comparison can be detrimental for self-esteem and social anxiety (Kosten et al., 2013), which suggests that social awareness may predispose one to difficulties that increase the likelihood of conformity. Fear also plays a role in submission. Those who are physically, emotionally, or intellectually frail may fear harm and humiliation that can accompany resistance to influence attempts. Fear is also hypothesized to motivate conformity among children with few friends and those who have difficulty making friends (Laursen et al., 2012). In this view, the consequences of potentially losing a friend by resisting demands and acting in ways that reinforce dissimilarities outweigh downsides associated with conformity.
Research is consistent with the view that vulnerabilities heighten susceptibility to influence. Some ethnic minorities report high levels of trait conformity (Steinberg & Monahan, 2007). Early maturing girls report heightened susceptibility to peer influence over risk-taking behaviors (Kretsch et al., 2016). Strong evidence implicates social anxiety in susceptibility to peer influence. In experimental conditions, socially anxious adolescents demonstrated public conformity and internalization of attitudes in response to feedback from all peers, even those who were low status; by contrast, nonanxious adolescents limited their conformity to high-status peers (Cohen & Prinstein, 2006). As hypothesized, low self-concept is a risk factor for conformity. In a longitudinal study of best friend influence on delinquency, adolescents who reported low self-concept clarity were more susceptible to best friend influence than those with high self-concept clarity (Levey et al., 2019). Finally, indirect support for trait theory comes in the form of evidence that indicates that some individuals have attributes that make them relatively impervious to peer influence. Adolescents high on callous–unemotional and grandiose–manipulative traits are more resistant to conformity than others (Kerr et al., 2012).
Popularity and Social Goals
Upward strivers may be susceptible to influence. Youth who aspire to be popular think they need to behave like those who are popular. Their emulation is a form of conformity. Deviance regulation theories (Blanton & Christie, 2003) hold that punishment awaits those who stray from group norms. Members fear the loss of approval and the potential for exclusion that accompanies being viewed as dissimilar. Conversely (and perhaps counterintuitively), leaders also fear being seen as out of step with group members, which might result in a loss of status and a dilution of power (Allen et al., 2005). One consequence may be that leaders are less likely to stray from group norms than rank-and-file group members. It follows that popularity goals should also heighten susceptibility. Those who want to be popular and those who are oriented toward attaining greater popularity should demonstrate greater conformity than those who do not share similar goals. Those climbing the social ladder must be sensitive to the behaviors of popular others; once popularity is achieved, they must pay more attention to in-group members. Some have theorized that goals may be shaped by prototypes, defined as cognitions and images of targets. The targets may be popular others or they may be those who engage in particular forms of behavior (Reynolds & Crea, 2015). Susceptibility to influence may be greatest among those whose prototypes emphasize the benefits as opposed to the risks associated with adopting a behavior or status goal.
We recognize that some will disagree with our characterization of popularity as a trait-like attribute, but this overlooks the fact that popularity is stable within the peer group (Dijkstra et al., 2013) as are popularity goals (Kiefer & Ryan, 2008). Of course, there are situations that elicit a desire for greater popularity or acceptance. Little is known about state-like variability in popularity and popularity motives, but should such evidence arise it would not contradict claims about links between low status and susceptibility to peer influence.
The bulk of the evidence leans toward the conclusion that unpopular adolescents are susceptible to peer influence. Several studies indicate that low popularity is a risk for heightened conformity (e.g., Dijkstra et al., 2010; Gommans et al., 2017; Laninga-Wijnen et al., 2017). Similar findings emerge for peer rejection (e.g., Pál et al., 2016). One study from the current special section illustrates how low-status youth reflect the prevailing norms of the school; the degree to which rejection was associated with academic performance varied as a function of peer school engagement norms (Lessard & Juvonen, 2020). The evidence for acceptance is mixed, with some studies reporting that low accepted youth are more susceptible to peer influence than high accepted youth (e.g., Snyder et al., 2010), and others, including one in this special section, reporting the opposite (e.g., Allen et al., 2020). To our knowledge, only one study provides support for the paradoxical popularity-socialization hypothesis. In this study, adolescent social preferences scores (liked-most minus liked-least nominations) predicted increases in problem behaviors in peer groups whose members endorsed misconduct (Allen et al., 2005). The latter findings could be interpreted to mean that high-status members shape the behaviors of peer-group members by staying ahead of salient trends rather than conforming to the behaviors of group members. Other findings reported in the current special section indicate that adolescents with positive relations with friends and mothers are more susceptible to influence from friends over substance use (Allen et al., 2020), painting a picture that suggests that well-adjusted adolescents are especially accommodating, contrary to assertions that troubled adolescents are most likely to conform. Finally, adolescents focused on social goals report a clear link between perceptions of peer substance use and intentions to engage in substance use in the future (Trucco et al., 2011). Agentic social goals also moderate the association between peer norms and adolescent behavioral change; those who aspire to social dominance and social status exhibited greater conformity to peer drinking norms over time than adolescents with low agentic goals (Meisel & Colder, 2015).
Cognitive and Socioemotional Immaturity
Maturational status has hypothesized links to susceptibility. The arrested socialization hypothesis proposes that repeated engagement in problem behavior interferes with the development of self-regulation skills (Dishion et al., 2008). An inability to regulate emotions and behaviors may make one susceptible to peer influence, presumably because impulsivity elevates the propensity to focus on the immediate rewards of conforming to peer demands, without considering the potential downsides that may follow. Neurological maturation has been linked to executive function and emotional regulation skills (Güroğlu & Veenstra, in press). Thus, individual differences in brain maturation should be tied to levels of peer conformity. Perceiving and interpreting social stimuli is confounded by increased reactivity to emotional input and reward sensitivity in adolescence, which predisposes some to be susceptible to peer influence (Smith et al., 2015). Finally, uncertainty about identity may elicit conformity (Berger, 2008). Those who lack a clear identity to guide actions may look to others for input on behaviors. Susceptibility is apt to be heightened in the period between de-identification with parents and the establishment of a unique, independent identity (Laursen, 2018). Absent a clear sense of self, youth may reasonably assume that outward conformity is a first step in the establishment of an identity. Those who are in the midst of identity exploration may try on different identities, which may involve emulating the behaviors of a rotating cast of those who personify a desired identity.
Several studies tie neurological maturation to susceptibility to peer influence. Longitudinal results support the assertion that low self-regulation predicts increases in peer conformity (Goodnight et al., 2006). Reward-dominant individuals were also high on susceptibility to peer influence over deviant behaviors, which anticipated subsequent increases in externalizing behaviors. Another study indicated that high susceptibility to peer influence is associated with less connectivity in brain regions associated with attentional control and inhibition of prepotent responses, particularly when individuals are presented with negative emotions (Grosbras et al., 2007). Brain imaging studies indicated that high susceptibility to peer influence is associated with increased activity in brain regions associated with social-cognitive and social-affective sensitivity during conditions of exclusion; adolescents who experience increased activity in brain regions associated with social cues related to theory of mind and social exclusion evinced high susceptibility to influence on risk-taking behaviors (Falk et al., 2014). In addition, adolescents who experience greater activations in brain regions associated with risk processing were most susceptible to influence by risk-taking peers (Pei et al., 2020).
Links between identity development and peer influence are not well-studied. One investigation examined identity exploration and commitment as moderators of the concurrent association between peer-group pressure and engagement in substance use (Dumas et al., 2012). Perceptions of peer-group peer pressure were associated with greater substance use in adolescents who reported low-identity commitment but not high, and perceptions of peer-group peer pressure were associated with more deviant behaviors in adolescents who reported low-identity exploration, but not high (Dumas et al., 2012). Similar findings emerged in a longitudinal study, such that low self-identity was prospectively associated with increases in susceptibility to influence and susceptibility to influence was associated with decreases in self-identity (Forney & Ward, 2019).
Limitations and Challenges Confronting the Study of Susceptibility
The field of peer influence is remarkable for the wealth of conceptual models available. In many instances, however, conclusions derived from these models outstrip empirical evidence. Longitudinal support, in particular, is in short supply, making conclusions about order of effects problematic.
Research strategies often provide less than optimal tests of the susceptibility hypotheses advanced. Distinctions between states and traits as sources of susceptibility are rarely acknowledged. As a consequence, conformity tends not to be explicitly and uniquely tied to characteristics of individuals or characteristics of situations; all too often the two are combined or confounded. In an ideal world, scholars would predict conformity from endogenous and exogenous characteristics of the target of influence, some of which are specific to the setting, episode, and behaviors of the agent of influence (implying an interaction between target attributes and either agent attributes/behaviors or circumstances/settings). Unfortunately, the data rarely permit this level of nuance. Instead, variables purporting to measure target susceptibility are operationalized as moderators in a generic peer influence model. In the usual scenario, the hypothesized susceptibility variable is included as a predictor of change in the target’s behavior and as a moderator of the association between the agent’s behavior and changes in the target’s behavior (Prinstein, in press). The analyses are frequently underpowered and unable to disentangle combinations of agent and target attributes from factors allegedly responsible for conformity.
Skepticism should be directed toward studies that simply tie measures of trait-like susceptibility to changes in the same individual’s outcome, because it is not clear why higher levels of susceptibility must inevitably lead to increases in a specific behavior. To wit, heightened susceptibility to peer influence should not necessarily lead to increases in alcohol use among all adolescents, but rather only among those in the company of heavier drinkers. Hypothetical measures of conformity also merit extra scrutiny. Apparent developmental shifts in conformity may be a product of developmental changes in standards of behavior and preferences for activities that have little or nothing to do with susceptibility (Berndt, 1999). It should also be noted that self-report measures of susceptibility to peer influence are not well-validated. Needed are observational studies that tie perceptions of the self to observed conformity with peers. Then too, as noted at the outset, it remains difficult to determine whether conformity occurred because the agent was influential or the target was susceptible to influence.
Finally, many empirical studies are guilty of conflating measures of susceptibility with measures of maladaptive behavior (we thank a reviewer for pointing this out). The problem manifests itself differently. Perhaps most obviously, risk-taking behaviors, in and of themselves, are not necessarily indicative of conformity or susceptibility. Less obvious but equally problematic is the fact that studies that identify high levels of similarity between friends or group members on problem behaviors invariably emphasize similarity at the high end of the scale but not at the low end of the scale, despite that fact that both contribute (more or less) equally to the observed association. The result is that conformity is equated with problematic outcomes. In concurrent terms, friends with high levels of a maladaptive behavior tend to resemble one another and so also do friends with low levels of the same behavior. In longitudinal terms, to say that one friend’s maladaptive behavior influences the other friend’s maladaptive behavior is to say that higher levels of maladaptive behavior on the part of one friend predict increases on the part of the other friend (a bad thing); the same association also implies that lower levels of maladaptive behavior on the part of one friend predict decreases on the part of the other friend (a good thing). Equally, unsettling is the fact that self-report indices of susceptibility and extreme peer orientation tend to conflate the tendency to misbehave with the tendency to go along with age-mates. Examples include “Some people will not break the law just because their friends say that they would BUT Other people would break the law if their friends said that they would break it” (Steinberg & Monahan, 2007) and “It’s okay to break some of your parents’ rules to keep your friends” (Fuligni & Eccles, 1993). Questions about conformity to problem behaviors are not typically offset by questions about conformity to positive behaviors, effectively rendering the assessments measures of susceptibility to negative influence. One solution is to only include questions that assay conformity in global terms. Another is to heed Berndt’s (1979) admonition that conformity is multidimensional and, as such, susceptibility should be separately measured in positive, neutral, and negative terms.
Developmental Changes that Affect Susceptibility to Peer Influence
Peer influence is often claimed to be strongest among adolescents, peaking during the early to mid-adolescent years (Laursen & Veenstra, 2021). Before we discuss what this means for susceptibility, it is worth noting the remarkable absence of lifespan work on peer influence. Of the few cross-age comparisons that exist, most contrast developmental periods within adolescence or with those adjacent to adolescence. Thus, claims that susceptibility to peer influence is at its apex during adolescence are driven primarily by compelling conceptual arguments.
A host of maladaptive behaviors arise rather suddenly during adolescence. Conventional wisdom attributes these changes to heightened peer pressure because they coincide with shifts in the social world that elevate the importance of peers, often at the expense of parents and other adults. It should not be necessary to point out that causality cannot be concluded from concurrent shifts in behavior, particularly when those shifts coincide with a host of other physical, cognitive, and social changes. Furthermore, given the distinction made earlier between being influential and being susceptible to influence, scholars should be wary of equating evidence concerning age-related shifts in similarity or demonstrations of peer influence with evidence concerning age-related shifts in susceptibility to peer influence.
Conceptual Models of Developmental Change in Susceptibility to Peer Influence
Theories that address developmental changes in peer influence often begin with the observation that the timing of adjustment difficulties attributed to peer pressure coincide with the transition from primary school to middle school (Laursen & Veenstra, 2021). Throughout childhood, conformity to adults is assumed to prevail over that with peers (Berndt, 1979). At the onset of middle school, however, adult oversight retreats and schools become less personal (Eccles et al., 1996). Adolescents spend less time with parents and more time with age-mates (Laursen & Williams, 1997). Seen in this light, susceptibility to peer influence can be viewed as an adaptive strategy. Leaving the adult-supervised environment of primary school requires adjustment; middle school students must rely on friends for protection and guidance as they navigate contexts where norms are created and enforced by peers. The consequences of nonconformity, it is argued, are too steep to be ignored.
Why, then, does peer conformity decline after middle school? Identity theorists argue that the early years of adolescence are marked by exploration (Côté, 2009). Conformity facilitates exploration, permitting youth to try, and discard different identities as they move between crowds and friends (Kerpelman & Pittman, 2001). Conformity is assumed to be at its highest when identity uncertainty is at its peak, consistent with the taste uncertainty principle (Moutoussis et al., 2016). As adolescents become more secure in their identities and more focused on attaining young adult roles, motives for peer conformity abate. Knowing who you are should make it easier to deflect pressure from peers, particularly when it comes to deviating from core identity principles. Then too, once an identity comes into focus, friends and peer groups are selected on the basis of shared features that define the over core features of the self, suggesting less room for peers to exercise influence.
One flaw in the environmental-structural and identity arguments is the failure to acknowledge important changes in social contexts and identities that take place during the late adolescent and young adult years. As romantic relationships grow in importance, they eventually eclipse and replace friends. Identities become increasingly tied to pair bonding. A case could be made that peer conformity does not decrease across adolescence but instead assumes a different form. Adolescents involved in romantic relationships tend to spend more time in the company of romantic partners than in the company of friends (Laursen & Williams, 1997). Romantic partners expect behavioral convergence, because it facilitates intimacy and exclusivity (Gonzaga et al., 2007). Inexperience and anxiety about romantic interactions may make adolescents especially eager to conform to the wishes of a partner. Forced to choose between conflicting behavioral prescriptions, adolescents may opt to conform to romantic partners rather than friends on grounds that the latter is more resilient than the former (Furman, 2018). A similar argument may be extended into the adult years, when employment success often depends on conformity to work affiliates and employers. To summarize: Scholarly assumptions about declining susceptibility grounded in the waning significance of friendships overlook the possibility that adolescent and young adult conformity may instead shift from one set of peers to another, in this case from friends and affiliate groups to romantic partners and work colleagues.
The influence-compatibility model (Laursen & Veenstra, 2021) starts from the premise that peer influence serves to increase similarity, which promotes compatibility, an essential component of success in the adolescent social world because it reduces the risk of friendlessness and exclusion from the group. It follows that susceptibility to peer influence should be greatest when close friendships and membership in a peer group are most crucial, typically during early and mid-adolescence. According to this view, conformity is a strategy for getting along; it reduces disagreements over differences, which threaten relationship satisfaction. Compatibility is particularly important in voluntary relationships, where participants are free to discontinue an affiliation in favor of more attractive alternatives. Thus, conformity to parents may reduce some friction, but it is not essential to the continuity of the relationship, as is probably the case with conformity to friends. Developmental shifts in conformity should reflect interpersonal priorities. As friendships assume a position of primary importance during middle childhood and early adolescence, there should be evidence of enhanced conformity to friends. As romantic relationships replace friends in the hierarchy of relationships during mid to late adolescence and early adulthood, there should be evidence of enhanced conformity to romantic partners.
Empirical Evidence of Developmental Change in Susceptibility to Peer Influence
The strongest indication of age-related shifts in peer influence comes from perceptual conformity tasks, wherein participants are given the opportunity to change their stated views after hearing those of others. Several cross-sectional studies have identified inverted, U-shaped developmental trends, with response shifts increasing across middle childhood, plateauing in early and mid-adolescence, then declining through late adolescence and young adulthood (Knoll et al., 2015; Large et al., 2019). Self-reports yield findings that resemble studies of perceptual conformity. Mid-adolescents report being more inclined to engage in hypothetical misconduct at the urging of a peer than do younger or older adolescents (Berndt, 1979; Sim & Koh, 2003). The same studies did not, however, reveal similar trajectories in assessments of influence in neutral or positive domains of behavior. Scores on self-report inventories that gauge resistance to peer pressure—tracked longitudinally—increase gradually from age 14 to 20, with little change thereafter, suggesting a gradual decline across adolescence in susceptibility to peer influence; cross-sectional findings also indicate a steady uptick in resistance to peer pressure, although they differ somewhat as to whether early or mid-adolescence marks the nadir (Steinberg & Monahan, 2007). Finally, studies that trace changes in similarity between relationship partners yield familiar developmental trends. Consistent with the argument that conformity rises and falls across adolescence, longitudinal findings indicate that friend similarity on deviant behavior increases from age 11 to 13, then declines from age 14 to 16 (Richmond et al., 2019). Consistent with the argument that conformity shifts as a function of relationship priorities, longitudinal evidence indicates that adolescents become more similar to new romantic partners and less similar to friends after the onset of a new romantic relationship, to the point where most resemble romantic partners more than friends (DeLay, Laursen, Bukowski, et al., 2016). Studies of similarity are proxies for conformity, because they assume that change is a product of the target’s desire to more closely resemble the agent; it is possible that changes in similarity could instead be a product of developmental shifts in the characteristics that make agents influential.
Proliferating indirect evidence suggests that brain maturation may play a role in susceptibility to peer influence. Adolescence is characterized by heightened risk-taking (Ciranka & van den Bos, 2021), which coincides with neural development that increases the salience of social and emotional stimuli, particularly from peers (Schreuders et al., 2019). The neural underpinnings of peer experiences are carefully reviewed elsewhere (see Güroğlu & Veenstra, in press). Suffice it to say that uneven brain maturation during early and mid-adolescence creates a unique developmental phenomenon whereby the presence of peers activates neural regions associated with reward processing, which increases rewards arising from novelty and risk-taking (Smith et al., 2015). It would appear that maturational changes make interactions with peers more rewarding and stimulating during adolescence than at other age periods; risk-taking in the presence of peers may well flow from neural rewriting. Identifying developmental changes that make certain behaviors more fun and rewarding, however, are not the same as identifying developmental changes that make one more susceptible to conformity pressures. The distinction is important: Responsiveness is not a synonym for susceptibility. Adolescents in the company of peers are less likely to evaluate the consequences of their actions and more likely to engage in rewarding behaviors, which increases the likelihood of doing all sorts of things, only some of which entail doing what everyone else is doing. Consider the following. When confronted with conflicting endorsements for risk-taking behavior, adolescents are more likely follow the lead of parents rather than peers (Kwon et al., 2021), which suggests that heightened reward systems do not necessarily translate into heightened conformity to peers.
Closing Thoughts
Peer influence is a process that involves at least two participants: The agent of influence (the influencer) and the target of influence (the influencee). Peer influence occurs when the agent sways the target to do something they would not otherwise do. Peer influence, a dyadic or group process, ought not to be conflated with susceptibility to peer influence, which concerns the target of influence only. Herein, we define susceptibility to peer influence as a characteristic of the target that increases their likelihood of conformity. Sometimes conformity can be traced to enduring trait-like attributes that consistently enhance susceptibility. Other times conformity can be traced to context-specific state-like attributes that conditionally enhance susceptibility. The distinction is critical because the former implies that some individuals are at heighted risk for conformity, regardless of partner or circumstance, whereas the latter implies that there are some times and some settings in which most individuals are at heightened risk for conformity.
Several streams of thought (and evidence) would seem to agree that susceptibility to peer influence is greatest during early to mid-adolescence. Caution is warranted in embracing this conclusion. There are not over many empirical studies on the topic; small samples and cross-sectional research are overrepresented. To complicate matters, developmental studies of susceptibility tend to overlook distinctions between conformity linked to states and conformity linked to trait-like attributes. Both self-reports and perceptual shift tasks, which at first glance would appear to tap trait-like attributes, are known to mix a variety of context-specific stimuli in assessments. Self-reports also tend to focus heavily on misbehavior. The water gets muddy quickly. The honest observer would conclude that it is impossible to say with any certainty that susceptibility on the basis of a specific trait-like attribute rises and falls across the lifespan. Even the strongest evidence, such as that emerging from research on brain maturation, is not sufficiently broad as to separate a reliable signal of maturation-linked differences in susceptibility from the noise arising from the use of different scenarios and circumstances as stimuli. The same observer would have even more difficulty identifying developmental changes in susceptibility, which are specific to contexts and settings.
The importance of the topic cannot be overstated. Clarity about susceptibility will provide much needed insight into when and how peer influence has detrimental consequences and when and how it may be beneficial. Youth who are susceptible to adverse peer influence would profit from interventions designed to mitigate their vulnerabilities. Identifying circumstances that heighten susceptibility to peer influence is a first step in helping all youth avoid or anticipate problems and maximize the potential for advantage.
Footnotes
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Brett Laursen and Sharon Faur received support for the preparation of this paper from the US National Institute of Child Health and Human Development (HD096457).
