Centrality in social networks conceptual clarification

The intuitive background for measures of structural centrality in social networks is reviewed and existing measures are evaluated in terms of their consistency with intuitions and their interpretability.Three distinct intuitive conceptions of centrality are uncovered and existing measures are refined to embody these conceptions. Three measures are developed for each concept, one absolute and one relative measure of the centrality of positions in a network, and one reflecting the degree of centralization of the entire network. The implications of these measures for the experimental study of small groups is examined.     

Centrality in social networks: ii. experimental results

Three competing hypotheses about structural centrality are explored by means of a replication of the early MIT experiments on communication structure and group problem-solving. It is shown that although two of the three kinds of measures of centrality have a demonstrable effect on individual responses and group processes, the classic measure of centrality based on distance is unrelated to any experimental variable. A suggestion is made that the positive results provided by distance-based centrality in earlier experiments is an artifact of the particular structures chosen for experimentation.     

One-mode projection analysis and design of covert affiliation networks

Within the field of national security and counterterrorism a great need exists to understand covert organizations. To better understand these cellular structures we model and analyze these cells as a collection of subsets of all participants in the covert organization, i.e., as hypergraphs or affiliation networks. Such a covert affiliation network structure is analyzed by evaluating the one-mode projection of the corresponding hypergraph. First we provide a characterization of the total distance in the one-mode projection using its corresponding cell-shrunken version. Secondly we evaluate the one-mode projection with respect to the secrecy versus information tradeoff dilemma every covert organization has to solve. We present and analyze affiliation networks representing common covert organizational forms: star, path and semi-complete hypergraphs. In addition we evaluate an example of a covert organization wishing to conduct an attack and compare its performance to that of the common covert organizational forms. Finally we investigate affiliation networks that are optimal in the sense of balancing secrecy and information. We show how any affiliation tree can be improved by altering its structure. Finally we prove that among covert organizational forms in the class of hypertrees with the same number of cells uniform star affiliation networks are optimal.     

Centrality and network flow

Centrality measures, or at least popular interpretations of these measures, make implicit assumptions about the manner in which traffic flows through a network. For example, some measures count only geodesic paths, apparently assuming that whatever flows through the network only moves along the shortest possible paths. This paper lays out a typology of network flows based on two dimensions of variation, namely the kinds of trajectories that traffic may follow (geodesics, paths, trails, or walks) and the method of spread (broadcast, serial replication, or transfer). Measures of centrality are then matched to the kinds of flows that they are appropriate for. Simulations are used to examine the relationship between type of flow and the differential importance of nodes with respect to key measurements such as speed of reception of traffic and frequency of receiving traffic. It is shown that the off-the-shelf formulas for centrality measures are fully applicable only for the specific flow processes they are designed for, and that when they are applied to other flow processes they get the “wrong” answer. It is noted that the most commonly used centrality measures are not appropriate for most of the flows we are routinely interested in. A key claim made in this paper is that centrality measures can be regarded as generating expected values for certain kinds of node outcomes (such as speed and frequency of reception) given implicit models of how traffic flows, and that this provides a new and useful way of thinking about centrality.     

Scaling and statistical models for affiliation networks: patterns of participation among Soviet politicians during the Brezhnev era

We use scaling and statistical models to study networks of ties among Soviet politicians during the Brezhnev era created by their co-attendance at events. The data consist of observations made by the National Foreign Assessment Center of the Central Intelligence Agency of appearances of Soviet political elites at official and social events for 8 years during the height of the Brezhnev era. Conventional wisdom characterizes the Soviet system as partimonial rather than bureaucratic in nature, that is, a system in which power is exercised through loyalties to key players often rooted in common regional and educational associations. One, therefore, might expect that co-attendance at events over these 8 years to be unrelated to actor’s formal positions and the nature of the events. However, our scaling models reveal that participation is patterned by the state and party offices elites hold. Random graph models provide tests of hypotheses about structural features of this network and confirm the interaction between politicians’ offices and the types of events which they jointly attend. Our discussion of the substantive implications of our analyses highlights the need for more detailed examination of “career tracks” through the co-participation space, particularly deviant career tracks and the need for a companion analysis of the structuring participations by informal power groups like those identified by Willerton [Soviet Stud. 34 (1987) 175].     

Religious affiliation and the family

The process of religious affiliation is mediated by institutions such as the family, which provide a network of ties to the public sphere. Variations in the likelihood of those with no religious affiliation in high school (N=900) becoming church members by the time they reach 30 are explained in terms of a combination of individual attributes, such as educational and spatial mobility, and changes in structural location, such as the transition to marital and parental status. Panel data from the Career Development Study show that women's chances of affiliation are more affected than are men's by parents' religious homogamy, getting married, and having children.     

Effects of Commitment and Psychological Centrality on Fathering

Propositions from identity theory suggest that interactional and affective commitment to a role identity affects the psychological centrality of that role identity. In turn, the centrality of one's role identity translates into role performance ( Stryker & Serpe, 1994 ). This conceptual model was tested with a sample of 186 fathers in first marriages with at least one child 18 years or younger. The results showed that fathers who perceived their wives as evaluating them positively as fathers were more likely to report higher levels of involvement in child‐related activities and place greater importance on the father role identity. This prominence, in turn, was associated with higher levels of involvement.     

Centrality and power revisited: actor success in group decision making

For many years, network analysts viewed positional centrality as a source of social power. More recently, laboratory studies of exchange networks have called the centrality–power link into question: under zero-sum exchange conditions, the ability of certain actors to directly exploit others has been found to account for power independent of actors' centrality. But most observers believe that in non-zero-sum communication networks, centrality should positively affect power. In this study we examine the effect of centrality on power in a communication network involving group voting on political issues. Using a model in which actors' votes are determined by the strength of their initial positions and the social pressures to which they are subjected, we conduct computer simulations to examine the extent to which actors in various network positions achieve favorable political outcomes. Our findings indicate that the link between centrality and power is highly contingent on the structure of the network. In networks with a central actor and an odd number of subgroups, central actors fail to dominate. In fact, in these networks, when peripheral actors are able to directly influence one another, the central actor becomes the least powerful in the network. In networks with a central actor and an even number of subgroups, however, the central actor dominates even in situations with connected peripherals. The highly contingent effect of centrality on power accords with the findings of exchange theorists who have studied power under zero-sum conditions. This raises questions about the nature of the distinction between communication and exchange networks.     

The Centrality of Social Presence in Online Teaching and Learning in Social Work

Social presence is the extent to which persons are perceived to be real and are able to be authentically known and connected to others in mediated communication. A full appreciation of the concept offers social work educators an antidote to skepticism of online learning and provides an avenue for modeling the development and maintenance—indeed, the transformation—of collaborative helping relationships essential to practice. This article opens with a discussion of the place of social presence in its larger conceptual, theoretical, and empirical context and presents identified components along with concrete examples for effectively building social presence into online teaching. We conclude with a discussion of real-world challenges and tensions and pose a series of questions for future research.     

Marginalized within the Margins: Minority Stress and Identity Centrality

Research documents how identity linked processes may have important health implications for people with marginalized or stigmatized identities. While previous work suggests that certain dimensions of identity may moderate the impact of minority stressors to wellbeing, work on identity centrality has yielded mixed findings about the directionality of the relationship between centrality and health. Given the importance of identity centrality on self-concept, this study highlights how differential exposure to minority stressors matters for identity construction. Drawing from 25 in-depth interviews on Black and Latino/a sexual minority adults, I examine perceptions of identity centrality and exposure to minority stressors. There are three key findings to highlight. First, results present evidence of intra-group variability in identity centrality. Second, results indicate that differential exposure to minority stress matters for perceptions of identity centrality. Finally, results note that differentiating between stigma and race related stressors is necessary to better understand experiences of minority stress.     

Multimodal accomplishment of alignment and affiliation in the local space of distant meetings

ABSTRACT

Technology-mediated (i.e. distant) meetings are complex settings that involve distributed participation frameworks and the coordination of actions in multiple interactional spaces. This paper examines how problems with hearing, speaking, or understanding in the overall meeting space enable the negotiation of alignment and affiliation by co-present participants in the same local meeting space. Conversation analysis is used to investigate the local accomplishment of alignment and affiliation achieved through the sequential and temporal organization of verbal, embodied, and material resources of interaction in three types of situations: during technological trouble, silences, and disagreements. The analysis shows that the local participants draw on their physical setting and the material environment to make interactional problems relevant amongst themselves. During these parallel interactions, the co-construction of alignment and affiliation enhances the sense of local community and enables the building of alliances that are not made public in the overall meeting space.     

The Popular Kids Don't Matter: Centrality and Influence on Adolescent Behavior

This study examines the widely held belief that socially central individuals are disproportionately influential in their networks. Using data from the National Longitudinal Study of Adolescent Health, it models the association between four behavioral outcomes and two distinct specifications of the behaviors' relationship to network prominence. This study finds little evidence that sociometrically central individuals are more influential than randomly chosen peers from the same network when predicting drinking, smoking, and sports participation. Students resemble their peers in systematic ways, but it is unlikely that this is because central students serve as a reference for the group or because students adjust their actions based on the social rewards that they observe given their position in a social network.     

Social Support Networks and School Outcomes: The Centrality of the Teacher

This investigation compares school outcomes for students who differ in the extent to which they perceive their parents, friends, and teachers—each alone and in combination—as important sources of social support. Findings indicate that middle and high school students who perceive high supportiveness from all three sources of support, as opposed to none, one, or two, have better attendance; spend more hours studying; avoid problem behavior more; have higher school satisfaction, engagement, and self-efficacy; and obtain better grades. Positive school outcomes are promoted when teacher support is perceived in combination with perceived support from parents and friends. Implications of the results for human service providers are presented.     

The effect of religious concentration and affiliation on county cancer mortality rates

Previous research has documented lower cancer mortality rates among religious groups characterized by doctrinal orthodoxy and behavioral conformity. In addition, there is evidence that the general population in an area with a high concentration of religious participants may experience health benefits resulting from diminished exposure to or increased social disapproval of behaviors related to cancer mortality. This research examines the effect of religious concentration and denominational affiliation on county cancer mortality rates. Our findings suggest that religion has a significant impact on mortality rates for all malignancies combined, for digestive cancer, and for respiratory cancer when we control for demographic, environmental, and regional factors known to affect cancer mortality. These results provide new insight into the relationship between religion and health at the macro or community level and suggest that the influence of religion on social structure warrants further attention.     

Deviant peer affiliation,parent involvement,and aggressive behaviors of rural children in China

Aggressive behaviors in early childhood may indicate future violence, so effective intervention measures should be taken on time to promote children's physical and psychological health. Based on sampling survey data from Jintang County in Sichuan Province of China, this paper analyzes the mechanism of rural children's aggressive behaviors from the perspective of peer influences and examines the role of parent involvement in it. The results show that the deeper the degree of deviant peer affiliation, the poorer the psychosocial adaptation of rural children, which is more likely to lead to aggressive behaviors. Parent involvement can effectively inhibit the aggressive behaviors of rural children arising from deviant peer affiliation.     

Member support for union mergers: An analysis of an affiliation referendum

A changing labor relations climate has caused many national unions to merge with smaller independent unions in recent years. One aspect of the merger process concerns the willingness of independent union members to support affiliation with a national union (Chaison, 1986). This article examines the determinants of indivudual-level voting behavior using data gathered from members of an independent union who rejected a proposed affiliation with a national union in a membership referendum. Logistic regression results indicate that affiliation supporters perceived the affiliation as improving union effectiveness, were influenced by social support among co-workers in favor of the merger, and perceived the saliency of the independent union’s support for the affiliation proposal. Conversely, affiliation opposition was influenced by the employer’s “vote no” campaign and by perceptions that affiliation would lead to an increased probability of strikes and to future increases in dues.     

Early social exposure and later affiliation processes within an evolving social network

BackgroundWhile short-term experiments have found that exposure to social contacts affects likeability, this study investigates its long-term effects on friendships in an emerging network.MethodsOne hundred psychology freshmen indicated whether they attended an introductory event before the start of the academic year to assess early exposure and reported on the friendships they formed with their peers at the beginning, middle, and end of their first semester.ResultsRSiena network models revealed that students taking part in the introductory event were more likely to form friendships throughout the first semester, but less likely to keep them.DiscussionWhile early exposure to people in an emerging network might provide a head start for forming friendships for at least a semester, these friendships appear less stable than those of students who did not have that exposure.     

SELF-CONCEPT AS THE ORGANIZATION OF ROLES: Importance, Centrality, and Balance

Data from a set of middle-aged working men and women from the Raleigh-Durham-Chapel Hill metropolitan area are used to explore three different ways that individuals organize their self-concepts and infuse personal significance into their roles. Five sets of findings include the following: (1) both men and women identify many of their roles as personally significant, especially work and family roles; (2) men tend to attribute more importance and centrality to the role of worker than do women, while women tend to assign greater importance and centrality to most other roles; (3) different combinations of importance, centrality, and balance influence worker, spouse, and parent role satisfaction and identity meanings; (4) worker role centrality tends to have negative effects on spouse and parent role satisfaction and identity meanings; and (5) worker role importance and spouse centrality have a positive influence on self-esteem while worker centrality has a negative impact on self-esteem. The findings suggest that importance, centrality, and balance appear to be independent dimensions of personal significance that individuals ascribe to their roles.