Changing contexts: A quasi-experiment examining adolescent delinquency and the transition to high school.

In a quasi-experiment, we examine whether changing schools during the transition from 8th to 9th grade influences adolescent delinquency, using a sample of more than 14,000 students in 26 public school districts (PROSPER study). The dataset follows students for eight waves from 6th through 12th grade and facilitates a unique, direct comparison of students who change schools with those who remain in the same school during this period. Results show that students who transition between schools report significantly less delinquency after the shift than those who do not, and that this difference persists through 10th grade. This decline is most pronounced when adolescents from multiple middle schools move to a single high school (i.e., multifeeder transitions). Students who transition between schools have fewer delinquent friends and participate in less unstructured socializing following the change in school environment, which partially mediates their reduced delinquency. Results provide some support for theories of differential association and routine activities. Our findings highlight the role of a crucial, yet understudied, life transition in shaping adolescent delinquency. The results from this quasi-experiment underscore the potential of alterations in social context to significantly dampen juvenile delinquency throughout high school.

Adolescent friendship, cross-sexuality ties, and attitudes toward sexual minorities: A social network approach to intergroup contact.

Social ties between members of in- and outgroups are theorized to reduce individual levels of prejudice. However, instances of intergroup contact are not isolated events; cross-group interactions are embedded in broader networks defined by various social processes that guide the formation and maintenance of interpersonal relationships. This project reconsiders the potential benefits of intergroup contact by applying a network perspective to examine whether friendships between youth of different sexualities can shape individuals' homophobic attitudes. The impact of cross-sexuality ties is evaluated through the application of stochastic actor-oriented models (SAOMs) to a two-wave sample of Dutch adolescents. Results indicate that the benefits of cross-sexuality connections become negligible when we account for how patterns of network connectivity and segregation are informed by other individual-level traits, such as age, religious background, ethnicity, and gender. In other words, heterosexual adolescents who are situated in network positions that provide opportunities to form cross-sexuality friendships would be expected to report less homophobic attitudes even in the absence of this intergroup contact. These findings suggest that the cross-sexuality contact observed in the social world often represents instances of "preaching to the choir," limiting the potential for intergroup connections to challenge systems of social inequality.

Reciprocity, transitivity, and skew: Comparing local structure in 40 positive and negative social networks.

While most social network research focuses on positive relational ties, such as friendship and information exchange, scholars are beginning to examine the dark side of human interaction, where negative connections represent different forms of interpersonal conflict, intolerance, and abuse. Despite this recent work, the extent to which positive and negative social network structure differs remains unclear. The current project considers whether a network's small-scale, structural patterns of reciprocity, transitivity, and skew, or its "structural signature," can distinguish positive versus negative links. Using exponential random graph models (ERGMs), we examine these differences across a sample of twenty distinct, negative networks and generate comparisons with a related set of twenty positive graphs. Relational ties represent multiple types of interaction such as like versus dislike in groups of adults, friendship versus cyberaggression among adolescents, and agreements versus disputes in online interaction. We find that both positive and negative networks contain more reciprocated dyads than expected by random chance. At the same time, patterns of transitivity define positive but not negative graphs, and negative networks tend to exhibit heavily skewed degree distributions. Given the unique structural signatures of many negative graphs, our results highlight the need for further theoretical and empirical research on the patterns of harmful interaction.

Worth the Weight: Conceptualizing and Measuring Strong Versus Weak Tie Homophily.

Homophily, or the tendency for social contact to occur among those who are similar, plays a crucial role in structuring our social networks. Most previous work considers whether homophily shapes the patterns of all social ties, regardless of their frequency of interaction or level of intimacy. As complex network data become increasingly available, however, researchers need to evaluate whether homophily operates differently for ties defined by strong versus weak measures of strength. Here, I take this approach by first defining two variants of homophily: (1) strong tie homophily, or the tendency for ties with high measures of strength to cluster together similar peers, and (2) weak tie homophily, or the tendency for ties with low edge weights to connect same-attribute actors. Then, I apply valued ERGMs to demonstrate the utility of differentiating between the two variants across simulated and observed networks. In most networks, I find that there are observable differences in the magnitude of strong versus weak tie homophily. Additionally, when there are low levels of clustering on the attribute of interest, distinguishing between strong and weak tie homophily can reveal that these processes operate in opposite directions. Since strong and weak ties carry substantively different implications, I argue that differentiating between the two homophily variants has the potential to uncover novel insights on a variety of social phenomena.

Strong and weak tie homophily in adolescent friendship networks: An analysis of same-race and same-gender ties.

While we know that adolescents tend to befriend peers who share their race and gender, it is unclear whether patterns of homophily vary according to the strength, intimacy, or connectedness of these relationships. By applying valued exponential random graph models to a sample of 153 adolescent friendship networks, I test whether tendencies towards same-race and same-gender friendships differ for strong versus weak relational ties. In nondiverse, primarily white networks, weak ties are more likely to connect same-race peers, while racial homophily is not associated with the formation of stronger friendships. As racial diversity increases, however, strong ties become more likely to connect same-race peers, while weaker bonds are less apt to be defined by racial homophily. Gender homophily defines the patterns of all friendship ties, but these tendencies are more pronounced for weaker connections. My results highlight the empirical value of considering tie strength when examining social processes in adolescent networks.

Comparing targeting strategies for network-based adolescent drinking interventions: A simulation approach.

Public health researchers and social scientists highlight the promise of network-based strategies to inform and enhance interventions that curb risky adolescent health behaviors. However, we currently lack an understanding of how different variants of network-based interventions shape the distribution of targeted behaviors. The current project considers the effectiveness of five targeting strategies that are designed to have differential impacts on the health of program participants versus non-participants. Using simulations that are empirically-grounded in 28 observed school-based networks from the PROSPER study, we evaluate how these approaches shape long-term alcohol use for intervention participants and non-participants, separately, and consider whether contextual factors moderate their success. Findings suggest that enrolling well-connected adolescents results in the lowest drinking levels for non-participants, while strategies that target groups of friends excel at protecting participants from harmful influences. These trends become increasingly pronounced in contexts characterized by higher levels of peer influence.

Beyond Dyads and Triads: A Comparison of Tetrads in Twenty Social Networks.

Social psychologists focus on the microlevel features that define interaction, often attending to dyads and triads. We argue that there also is utility in studying how configurations of four actors, or tetrads, pattern our social world. The current project considers the prevalence of directed tetrads across twenty social networks representing five relationship types (friendship, legislative co-sponsorship, Twitter, advice seeking, and email). By comparing these observed networks to randomly generated conditional networks, we identify tetrads that occur more frequently than expected, or network motifs. In all twenty networks, we find evidence for six tetrad motifs that collectively highlight tendencies toward hierarchy, clustering, and bridging in social interaction. Variations across network genres also emerge, suggesting that unique tetrad structural signatures could define different types of interaction.

Tied Together: Adolescent Friendship Networks, Immigrant Status, and Health Outcomes.

This study examines the social integration of adolescent immigrants by directly analyzing the composition of their friendship networks. Using statistical network analysis, I first consider whether adolescents are more likely to befriend peers who share their immigrant generation status in a large, diverse sample of 7th through 12th graders from the National Longitudinal Study of Adolescent to Adult Health (n = 67,586). Next, I test whether having a higher proportion of same-generation friends can protect immigrant youth from experiencing negative health outcomes and adopting risky behaviors. Results indicate that adolescents are more likely to form friendships with peers who share their immigrant generation status and that this tendency is particularly strong for first-generation immigrants. Furthermore, immigrant youth with greater proportions of same-generation friends are less likely to report several negative health behaviors and outcomes. My findings suggest that same-generation friendships can serve as a protective mechanism for immigrant youth, which may help explain the existence of an immigrant health paradox.

Peer Influence, Friend Selection, and Gender: How Network Processes Shape Adolescent Smoking, Drinking, And Delinquency.

We examine gender differences in the extent to which the social network processes of peer influence and friend selection explain why adolescents tend to exhibit similar risky behaviors as their friends for three problem behaviors (smoking, drinking, and delinquency). Using dynamic Stochastic Actor-Oriented Models (SAOMs), we analyze five waves of data on a large sample of 13,214 adolescents from 51 friendship networks. While both processes explain patterns of risky activities for girls and boys, the delinquent behavior of girls is more susceptible to influence and girls are especially likely to select friends who have similar smoking behaviors to their own.