Friendship Selection

We model the formation of friendships as repeated cooperation within a set of heterogeneous players. The model builds around three of the most important facts about friendship: friends help each other, there is reciprocity in the relationship and people usually have few friends. In our results we explain how similarity between people affects the friendship selection. We also characterize when the friendship network won’t depend on the random process by which people meet each other. Finally, we explore how players’ patience influences the length of their friendship relations. Our results match and explain empirical evidence reported in social studies on friendship. For instance, our model explains why troublesome subjects have few friends.Friendship, cooperative game, grim trigger strategy, social networks

Adolescent smoking networks: The effects of influence and selection on future smoking

Submitted in fulfillment of KU faculty's Open Access Policy.Peer influence and peer selection have both been linked to the smoking behavior of adolescents. The present investigation uses social network analysis methodology to explore the simultaneous effects of both processes on adolescent smoking and smoking susceptibility over two time periods. Results suggest the effects of friendship selection in 6th grade on smoking behavior in 7th grade were primarily direct. Selecting smokers as friends in 6th grade predicted both smoking and smoking susceptibility in 7th grade, and selecting susceptibles predicted future friendship selection and peer influence. Influence processes were indirectly related to smoking. Smokers' influence in 6th grade predicts the selection of smokers as friends in 7th grade. Smokers' influence also demonstrated a protective effect when ties were not reciprocated

The salience of sport in cross-race friendship selection

In response to growing racial concerns, stakeholders have called for programs that facilitate positive cross-race interactions. Adolescence has been targeted as the most effective life stage to initiate programs promoting relationships. Since schools are one of the primary social influences on adolescent development, they have been emphasized as a particularly important setting for promoting intergroup contact. Sport plays an important role in the experiences of students, and contributes to intergroup relations within a school. The purpose of this study is to examine the unique effect of sport participation on cross-race friendship selection. Using data from Wave I of The National Longitudinal Study of Adolescent Health (Add Health), mixed-effects regression models and analysis of variance (ANOVA) were used to assess the effects of sport participation on friendship heterogeneity. Overall, participation in sport activities did not significantly influence the racial heterogeneity of adolescent’s friendship networks

Friendship selection and influence processes for popularity in early and mid-adolescents

Introduction This study examined the effect of popularity levels on friendship selection and friends' influence on popularity levels in early and mid-adolescence. Methods Participants were 4205 Spanish adolescents (M-age = 13.1 years at Wave 1; 48% girls) belonging to 160 classrooms in two waves. Adolescents were asked about their friendships and the popularity of their classmates. Results Longitudinal social network analyses showed that adolescents preferred similarly popular peers as friends. High popular classmates were more attractive as friends, particularly in early adolescence. Popular adolescents were more selective in their friendship nominations and adolescents with popular friends became more popular over time. These two effects were only significant in mid-adolescents, although comparative analyses showed a similar tendency at both age groups. Conclusions This study highlights the importance of popularity levels in adolescents' friendship selection and suggests that popularity, at the individual and group level, plays a relevant role in social development. Implications adapted to the different selection and influence processes in early and mid-adolescence are discussed

Community structure and ethnic preferences in school friendship networks

Recently developed concepts and techniques of analyzing complex systems provide new insight into the structure of social networks. Uncovering recurrent preferences and organizational principles in such networks is a key issue to characterize them. We investigate school friendship networks from the Add Health database. Applying threshold analysis, we find that the friendship networks do not form a single connected component through mutual strong nominations within a school, while under weaker conditions such interconnectedness is present. We extract the networks of overlapping communities at the schools (c-networks) and find that they are scale free and disassortative in contrast to the direct friendship networks, which have an exponential degree distribution and are assortative. Based on the network analysis we study the ethnic preferences in friendship selection. The clique percolation method we use reveals that when in minority, the students tend to build more densely interconnected groups of friends. We also find an asymmetry in the behavior of black minorities in a white majority as compared to that of white minorities in a black majority.Comment: submitted to Physica

The Role of Academic Status Norms in Friendship Selection and Influence Processes Related to Academic Achievement

This study examined the role of academic status norms in friendship selection and influence processes related to academic achievement across the 2nd year of secondary school (SNARE project; N = 1,549 students from 70 classes; M-age = 13.69 years). Academic status norms were operationalized as the class-level correlation between academic achievement and 4 types of peer status: popularity, acceptance, unpopularity, and rejection. Longitudinal social network analyses indicated that the unpopularity and popularity norm play a role in friendship selection processes (but not influence processes) related to academic achievement. In line with our hypotheses, the unpopularity norm in the classroom strengthened similarity-based friendship selection among low-achieving adolescents and predicted greater avoidance of academically similar friends among high-achieving adolescents. Also, the popularity norm strengthened friendship selection among similar peers, both among low and high achievers. Acceptance and rejection norms did not play a role in friendship processes. In sum, the average achievement of popular and unpopular peers shapes friendship preferences in the classroom, which may have important implications for adolescent academic development

Using a distributed Shapley-value based approach to ensure navigability in a social network of smart objects

The huge number of nodes that is expected to join the Internet of Things in the short term will add major scalability issues to several procedures. A recent promising approach to these issues is based on social networking solutions to allow objects to autonomously establish social relationships. Every object in the resulting Social IoT (SIoT) exchanges data with its friend objects in a distributed manner to avoid the need for centralized solutions to implement major functionalities, such as: node discovery, information search and trustworthiness management. However, the number and types of established friendship affects network navigability. This paper addresses this issue proposing an efficient, distributed and dynamic strategy for the objects to select the right friends for the benefit of the overall network connectivity. The proposed friendship selection model relies on a Shapley-value based algorithm mapping the friendship selection process in the SIoT onto the coalition formation problem in a corresponding cooperative game. The obtained results show that the proposed solution is able to ensure global navigability, measured in terms of average path length among two nodes in the network, by means of a distributed and wise selection of the number of friend objects a node has to handle

Predicting adolescent social networks to stop smoking in secondary schools

Social networks are increasingly being investigated in the context of individual behaviours. Research suggests that friendship connections have the ability to influence individual actions, change personal opinions and subsequently impact upon personal wellbeing. This paper explores the effect of individual friendship selection decisions, and the impact they may have on the overall evolution of a social network. Using data from a large smoking cessation programme in secondary schools, an agent based simulation aiming to predict the evolution of the adolescent social networks is created. The simulation uses existing friendship selection algorithms from link prediction literature, along with a new approach to link prediction, termed PageRank-Max. This new algorithm is based upon the optimisation of an individuals eigen-centrality, and is found to be more successful than existing methods at predicting the future state of an adolescent social network. This research highlights the importance of eigen-centrality in adolescent friendship decisions, and the use of agent-based simulation to conduct behavioural investigations. Furthermore, it provides a proof-of-concept for targeted interventions driven by social network analysis, demonstrating the utility of using emerging sources of social network data for public heath interventions such as with tobacco use which is a major global health challenge

The co-evolution of emotional well-being with weak and strong friendship ties

Social ties are strongly related to well-being. But what characterizes this relationship? This study investigates social mechanisms explaining how social ties affect well-being through social integration and social influence, and how well-being affects social ties through social selection. We hypothesize that highly integrated individuals - those with more extensive and dense friendship networks - report higher emotional well-being than others. Moreover, emotional well-being should be influenced by the well-being of close friends. Finally, well-being should affect friendship selection when individuals prefer others with higher levels of well-being, and others whose well-being is similar to theirs. We test our hypotheses using longitudinal social network and well-being data of 117 individuals living in a graduate housing community. The application of a novel extension of Stochastic Actor-Oriented Models for ordered networks (ordered SAOMs) allows us to detail and test our hypotheses for weak- and strong-tied friendship networks simultaneously. Results do not support our social integration and social influence hypotheses but provide evidence for selection: individuals with higher emotional well-being tend to have more strong-tied friends, and there are homophily processes regarding emotional well-being in strong-tied networks. Our study highlights the two-directional relationship between social ties and well-being, and demonstrates the importance of considering different tie strengths for various social processes