Similarity breeds connection. This principle—the homophily principle—structures network ties of every type, including marriage, friendship, work, advice, support, information transfer, exchange, comembership, and other types of relationship. The result is that people's personal networks are homogeneous with regard to many sociodemographic, behavioral, and intrapersonal characteristics. Homophily limits people's social worlds in a way that has powerful implications for the information they receive, the attitudes they form, and the interactions they experience. Homophily in race and ethnicity creates the strongest divides in our personal environments, with age, religion, education, occupation, and gender following in roughly that order. Geographic propinquity, families, organizations, and isomorphic positions in social systems all create contexts in which homophilous relations form. Ties between nonsimilar individuals also dissolve at a higher rate, which sets the stage for the formation of niches (localize...

/pdf/birds-of-a-feather-homophily-in-social-networks-3kjmeyr23w.pdf

Birds of a Feather: Homophily in Social Networks

/pdf/scalable-molecular-dynamics-with-namd-3j7xyc70g4.pdf

Scalable Molecular Dynamics with NAMD

Introduction 1. Woman's Place in Man's Life Cycle 2. Images of Relationship 3. Concepts of Self and Morality 4. Crisis and Transition 5. Women's Rights and Women's Judgment 6. Visions of Maturity References Index of Study Participants General Index

In a Different Voice. Psychological Theory and Women’s Development. Cambridge, MA (Harvard University Press) 1982.

Twitter, a microblogging service less than three years old, commands more than 41 million users as of July 2009 and is growing fast. Twitter users tweet about any topic within the 140-character limit and follow others to receive their tweets. The goal of this paper is to study the topological characteristics of Twitter and its power as a new medium of information sharing.We have crawled the entire Twitter site and obtained 41.7 million user profiles, 1.47 billion social relations, 4,262 trending topics, and 106 million tweets. In its follower-following topology analysis we have found a non-power-law follower distribution, a short effective diameter, and low reciprocity, which all mark a deviation from known characteristics of human social networks [28]. In order to identify influentials on Twitter, we have ranked users by the number of followers and by PageRank and found two rankings to be similar. Ranking by retweets differs from the previous two rankings, indicating a gap in influence inferred from the number of followers and that from the popularity of one's tweets. We have analyzed the tweets of top trending topics and reported on their temporal behavior and user participation. We have classified the trending topics based on the active period and the tweets and show that the majority (over 85%) of topics are headline news or persistent news in nature. A closer look at retweets reveals that any retweeted tweet is to reach an average of 1,000 users no matter what the number of followers is of the original tweet. Once retweeted, a tweet gets retweeted almost instantly on next hops, signifying fast diffusion of information after the 1st retweet.To the best of our knowledge this work is the first quantitative study on the entire Twittersphere and information diffusion on it.

https://ink.library.smu.edu.sg/cgi/viewcontent.cgi?article=7104&context=sis_research

What is Twitter, a social network or a news media?

Background 
The quality and quantity of individuals' social relationships has been linked not only to mental health but also to both morbidity and mortality.
Objectives 
This meta-analytic review was conducted to determine the extent to which social relationships influence risk for mortality, which aspects of social relationships are most highly predictive, and which factors may moderate the risk.
Data Extraction 
Data were extracted on several participant characteristics, including cause of mortality, initial health status, and pre-existing health conditions, as well as on study characteristics, including length of follow-up and type of assessment of social relationships.
Results 
Across 148 studies (308,849 participants), the random effects weighted average effect size was OR = 1.50 (95% CI 1.42 to 1.59), indicating a 50% increased likelihood of survival for participants with stronger social relationships. This finding remained consistent across age, sex, initial health status, cause of death, and follow-up period. Significant differences were found across the type of social measurement evaluated (p<0.001); the association was strongest for complex measures of social integration (OR = 1.91; 95% CI 1.63 to 2.23) and lowest for binary indicators of residential status (living alone versus with others) (OR = 1.19; 95% CI 0.99 to 1.44).
Conclusions 
The influence of social relationships on risk for mortality is comparable with well-established risk factors for mortality.

Please see later in the article for the Editors' Summary

/pdf/social-relationships-and-mortality-risk-a-meta-analytic-2ghmxi4ksm.pdf

Social Relationships and Mortality Risk: A Meta-analytic Review

Have the core discussion networks of Americans changed in the past two decades? In 1985, the General Social Survey (GSS) collected the first nationally representative data on the confidants with whom Americans discuss important matters. In the 2004 GSS the authors replicated those questions to assess social change in core network structures. Discussion networks are smaller in 2004 than in 1985. The number of people saying there is no one with whom they discuss important matters nearly tripled. The mean network size decreases by about a third (one confidant), from 2.94 in 1985 to 2.08 in 2004. The modal respondent now reports having no confidant; the modal respondent in 1985 had three confidants. Both kin and non-kin confidants were lost in the past two decades, but the greater decrease of non-kin ties leads to more confidant networks centered on spouses and parents, with fewer contacts through voluntary associations and neighborhoods. Most people have densely interconnected confidants similar to them. Som...

/pdf/social-isolation-in-america-changes-in-core-discussion-22yh6nmk5b.pdf

Social Isolation in America: Changes in Core Discussion Networks over Two Decades

Recent work on the organized sources of network ties and on the social structural determinants of association are synthesized to produce several hypotheses about homophily. These hypotheses are tested with data on 304 face-to-face groups from 10 communities. We find that friends are more similar on status dimensions than chance and that this homophily is produced both by the restricted opportunity structure offered by the group and by homophilous choices made within the group. Organizational heterogeneity leads to substantially greater dyadic status distance within the organization, while organization size consistently reduces dyadic status distance. At a given level of diversity, a larger group will permit more homophilous friendship pairing. However, correlated status dimensions create little reduction in dyadic social distance. In general, homogeneity within groups is the overwhelming determinant of homophily.

Homophily in voluntary organizations: Status distance and the composition of face-to-face groups.

behavioral, and intrapersonal characteristics. Homophily limits people's social worlds in a way that has powerful implications for the infor- mation they receive, the attitudes they form, and the interactions they experience. Homophily in race and ethnicity creates the strongest divides in our personal envi- ronments, with age, religion, education, occupation, and gender following in roughly that order. Geographic propinquity, families, organizations, and isomorphic positions in social systems all create contexts in which homophilous relations form. Ties be- tween nonsimilar individuals also dissolve at a higher rate, which sets the stage for the formation of niches (localized positions) within social space. We argue for more research on: (a) the basic ecological processes that link organizations, associations, cultural communities, social movements, and many other social forms; (b) the impact of multiplex ties on the patterns of homophily; and (c) the dynamics of network change over time through which networks and other social entities co-evolve.

BIRDS OF A FEATHER: Homophily

▪ Abstract The gender system includes processes that both define males and females as different in socially significant ways and justify inequality on the basis of that difference. Gender is different from other forms of social inequality in that men and women interact extensively within families and households and in other role relations. This high rate of contact between men and women raises important questions about how interaction creates experiences that confirm, or potentially could undermine, the beliefs about gender difference and inequality that underlie the gender system. Any theory of gender difference and inequality must accommodate three basic findings from research on interaction. (a). People perceive gender differences to be pervasive in interaction. (b). Studies of interaction among peers with equal power and status show few gender differences in behavior. (c). Most interactions between men and women occur in the structural context of roles or status relationships that are unequal. These s...

Lynn Smith-Lovin

Papers

Birds of a Feather: Homophily in Social Networks

Social Isolation in America: Changes in Core Discussion Networks over Two Decades

Homophily in voluntary organizations: Status distance and the composition of face-to-face groups.

BIRDS OF A FEATHER: Homophily

The gender system and interaction