Cyberbullying only rarely the sole factor identified in teen suicides

Cyberbullying — the use of the Internet, phones or other technologies to repeatedly harass or mistreat peers — is often linked with teen suicide in media reports. However, new research presented on Oct. 20, at the American Academy of Pediatrics (AAP) National Conference and Exhibition in New Orleans, shows that the reality is more complex. Most teen suicide victims are bullied both online and in school, and many suicide victims also suffer from depression.

For the abstract, "Cyberbullying and Suicide: A Retrospective Analysis of 41 Cases," researchers searched the Internet for reports of youth suicides where cyberbullying was a reported factor. Information about demographics and the event itself were then collected through searches of online news media and social networks. Finally, descriptive statistics were used to assess the rate of pre-existing mental illness, the co-occurrence of other forms of bullying, and the characteristics of the electronic media associated with each suicide case.

The study identified 41 suicide cases (24 female, 17 male, ages 13 to 18) from the U.S., Canada, the United Kingdom and Australia. In the study, 24 percent of teens were the victims of homophobic bullying, including the 12 percent of teens identified as homosexual and another 12 percent of teens who were identified as heterosexual or of unknown sexual preference.

Suicides most frequently occurred in September (15 percent) and January (12 percent) although these higher rates may have occurred by chance. The incidence of reported suicide cases increased over time, with 56 percent occurring from 2003 to 2010, compared to 44 percent from January 2011 through April 2012.

Seventy-eight percent of adolescents who committed suicide were bullied both at school and online, and only 17 percent were targeted online only. A mood disorder was reported in 32 percent of the teens, and depression symptoms in an additional 15 percent.

"Cyberbullying is a factor in some suicides, but almost always there are other factors such as mental illness or face-to-face bullying," said study author John C. LeBlanc, MD, MSc, FRCPC, FAAP. "Cyberbullying usually occurs in the context of regular bullying."

Cyberbullying occurred through various media, with Formspring and Facebook specifically mentioned in 21 cases. Text or video messaging was noted in 14 cases.

"Certain social media, by virtue of allowing anonymity, may encourage cyberbullying," said Dr. LeBlanc. "It is difficult to prove a cause and effect relationship, but I believe there is little justification for anonymity."

Wide circle of friends key to mid-life wellbeing for both sexes

 The midlife wellbeing of both men and women seems to depend on having a wide circle of friends whom they see regularly, finds research published online in the Journal of Epidemiology and Community Health.

A network of relatives is also important — but only for men — shows the study of more than 6500 Britons born in 1958.

The authors base their findings on information collected from the participants, all of whom were part of the National Child Development Study (NCDS), when they were aged 42, 45 and 50.

At the age of 42, participants completed a validated questionnaire (Malaise Inventory) to gauge their psychological wellbeing and provided details of their partnership and job status, as well as the age at which they left full time education.

Most had left school at the age of 16, had a partner and were in pretty good psychological health.

Their responses were used to predict the size and make-up of their friend and family networks by the age of 45, when they were asked to state how many friends and relatives they met up with once a month or more.

One in seven said they had no contacts with relatives outside their immediate household and around one in 10 said they had no friends. Four out of 10 men and around one in three women said they had more than six friends whom they saw regularly.

Employment had no bearing on the size of social networks, but education did.

Men who left full time education between the ages of 17 and 19 were 45% less likely to have a larger kinship network, while those staying on until 20 or beyond were 60% less likely to do so. The comparable figures for women were 17% and 60%, respectively.

Staying on in full time education after 16 also reduced the size of men's friendship network, but it increased women's — by 38% if they left between 17 and 19, and by 74% if they left after the age of 20.

Having a partner was associated with a larger kinship network. Being single reduced that probability by 31% for men and by 26% for women. But it had no impact on friendship networks. When participants' psychological wellbeing was assessed at the age of 50, the results showed a significant association between the number of friends and psychological wellbeing, the impact of which was greater for women.

Compared with those with 10 or more regular contacts, smaller networks of friends at the age of 45 were associated with significantly lower levels of psychological wellbeing for both sexes.

These findings were consistent irrespective of whether they had a partner/job or had had a mental health issue in the past.

Psychological wellbeing was also influenced by the size of kinship networks, although to a lesser extent than friendship — but only for men.

Psychological wellbeing was especially poor among those with no relatives or friends: among men this was 2.3 points lower if they had no relatives and 2.6 points lower if they had no friends compared with those with 10 or more regular social contacts.

For women, lack of friends had an even greater impact on wellbeing. This was 4 points lower if they had no friends. But a lack of relatives had no emotional impact.


Journal Reference:

  1. Noriko Cable, Mel Bartley, Tarani Chandola, Amanda Sacker. Friends are equally important to men and women, but family matters more for men's well-being. Journal of Epidemiology and Community Health, 2012; DOI: 10.1136/jech-2012-201113

Time with parents is important for teens' well-being

Teenagers are famous for seeking independence from their parents, but research shows that many teens continue to spend time with their parents and that this shared time is important for teens' well-being, according to Penn State researchers.

"The stereotype that teenagers spend all their time holed up in their rooms or hanging out with friends is, indeed, just a stereotype," said Susan McHale, professor of human development and director of the Social Science Research Institute at Penn State. "Our research shows that, well into the adolescent years, teens continue to spend time with their parents and that this shared time, especially shared time with fathers, has important implications for adolescents' psychological and social adjustment."

The researchers studied whether the stereotype of teens growing apart from their parents and spending less time with them captured the everyday experiences of families by examining changes in the amount of time youths spent with their parents from early to late adolescence. On five occasions over seven years, the team conducted home and phone interviews with mothers, fathers and the two oldest children in almost 200 white, middle- and working-class families living in small cities, towns and rural communities. At the start of the study, the oldest children in each family were about 11 and the second oldest were about 8 years old.

During the home interviews, teens reported on their social skills with peers and their self-esteem. After each home visit, the researchers also conducted a series of seven nightly phone interviews, asking teens about their activities during the day of the call, including who participated in the activities with them.

According to youths' reports of their daily time, although parent-teen time when others were also present declined from the early to late teen years, parent-teen time with just the parent and the teen present increased in early and middle adolescence — a finding that contradicts the stereotype of teens growing apart from their parents.

"This suggests that, while adolescents become more independent, they continue to have one-on-one opportunities to maintain close relationships with their parents," McHale said.

Furthermore, teens who spent more time with their fathers with others present had better social skills with peers, and teens who spent more time alone with their fathers had higher self-esteem.

The researchers also found that the decline in the time teens spent with parents and others was less pronounced for second-born than for first-born siblings. Thee also found that both mothers and fathers spent more time alone with a child of their same gender when they had both a daughter and a son.

The results appeared Aug. 21 in the journal Child Development.

Other authors on the paper include Ann C. Crouter, the Raymond E. and Erin Stuart Schutz Dean of the College of Health and Human Development and professor of human development, and Chun Bun Lam, doctoral student in human development and family studies when the research was performed.

The Eunice Kennedy Shriver National Institute of Child Health and Human Development funded this study.

Kinsey Reporter: Free app allows public to anonymously report, share information on sexual behavior

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The Kinsey Reporter platform is available free from Apple iOS and Google Play (for Android) online stores. Reports made by anonymous citizen scientists will be used for research and shared with the public at the Kinsey Reporter website. (Credit: Image courtesy of Indiana University)

 Indiana University has released Kinsey Reporter, a global mobile survey platform for collecting and reporting anonymous data about sexual and other intimate behaviors. The pilot project allows citizen observers around the world to use free applications now available for Apple and Android mobile platforms to not only report on sexual behavior and experiences, but also to share, explore and visualize the accumulated data.

"People are natural observers. It's part of being social, and using mobile apps is an excellent way to involve citizen scientists," said Julia Heiman, director of The Kinsey Institute for Research in Sex, Gender and Reproduction. "We expect to get new insights into sexuality and relationships today. What do people notice, what are they involved in, and what can they relate to us about their lives and their communities?"

The project will collect anonymous data and then aggregate and share it openly. Kinsey Reporter is a joint project between The Kinsey Institute and the Center for Complex Networks and Systems Research, or CNetS, which is part of the IU School of Informatics and Computing and the Pervasive Technology Institute. Both Kinsey and CNetS are based on the IU Bloomington campus.

CNetS director Filippo Menczer called development of the citizen reporting platform an opportunity to gather information on important issues that may have been difficult to examine in the past.

"This new platform will allow us to explore issues that have been challenging to study until now, such as the prevalence of unreported sexual violence in different parts of the world, or the correlation between various sexual practices like condom use, for example, and the cultural, political, religious or health contexts in particular geographical areas. These were some of our initial motivations for the project," he said.

Users simply download the free app and begin contributing observed information on topics such as sexual activity, public displays of affection, flirting, unwanted experiences and birth control use. Even though no information identifying users submitting reports is collected or stored, the time and general location of the report is collected and input into the database. Users also have the option of selecting their own geographic preference for the report by choosing city/town, state/region or country.

Surveys will change over time, and users can view aggregated reports by geographic region via interactive maps, timelines or charts. All of these reporting venues can be manipulated with filters that remove or add data based on specific survey topics and questions selected by the user.

Both Heiman and Menczer said The Kinsey Institute's longstanding seminal studies of sexual behaviors created a perfect synergy with research going on at CNetS related to mining big data crowd-sourced from mobile social media. The sensitive domain — sexual relations — added an intriguing challenge in finding a way to share useful data with the community while protecting the privacy and anonymity of the reporting volunteers, they added.

Reports are transmitted to Kinsey Reporter using a secure, encrypted protocol, and the only data collected are a timestamp, the approximate geo-location selected by the user, and the tags the user chooses in response to various survey questions. The protections and anonymity provided to those responding to surveys allowed IU's Institutional Review Board to classify the research as "exempt from review," which allows the data to be used for research and shared without requiring informed consent from users of the apps.

The Kinsey Reporter platform is now in public beta release. Apps are available for free download at both the Apple iOS and Android app stores. Accompanying the app release are a Kinsey Reporter website, a Twitter feed and a Facebook page. The four resources also provide links to information about sexuality, such as blogs and podcasts from the Kinsey Confidential website. YouTube videos on "What Is the Kinsey Reporter App" and "Making the Kinsey Reporter App" are also available for viewing.

The Kinsey Institute receives support from the Office of the Vice Provost for Research at IU Bloomington, which is dedicated to supporting ongoing faculty research and creative activity and developing new multidisciplinary initiatives to enhance opportunities for federal, state and private research funding.

Too soon? Too late? Psychological distance matters when it comes to humor

 Joking around can land us in hot water. Even the professionals often shoot themselves comedically in the foot. Last month, comedian Jeffrey Ross's routine at a roast of Rosanne Barr was censored when he joked about the shooting in Aurora, Colorado. "Too soon!" everyone said.

And yet, it's not quite as simple as certain topics being "too soon" to joke about. Two weeks after 9/11, The Onion was able to successfully publish a satirical issue about the terrorist attacks.

So the question is: When are tragedies okay to joke about — and when are they not?

According to the "Benign Violation Theory," humor emerges when we perceive something that is wrong (a violation), while also seeing that it is okay (benign). Psychological distance is one key ingredient that can make a violation seem okay and several studies have shown that being removed from a violation — by space, time, relationships, or imagination — enhances humor.

But new research suggests that psychological distance isn't the only feature that matters — the severity of the violation also plays an important role.

"Having some distance from tragedy helps to create a benign violation, which facilitates comedy," observes psychological scientist Peter McGraw, who runs the Humor Research Lab (HuRL) at the University of Colorado Boulder. "But when you become too distant from a mild violation, it's just not funny anymore."

Evidence

In a new article forthcoming in Psychological Science, a journal of the Association for Psychological Science, McGraw and colleagues explore how violation severity (how "bad" it is) and psychological distance (how removed we are) work together to facilitate humor.

In their first study, the researchers looked at the effect of psychological distance in terms of time. In an online survey, participants were asked to describe an event from their lives that either became more funny or less funny as time passed. Participants then rated the event's severity. In line with the researchers' hypothesis, events that became funnier over time were rated more severe than the events that lost their comedic effect, which were seen as mild violations.

These findings were supported by the results of a second study, in which participants reported a severe violation (being hit by a car) as funnier if they happened 'five years ago,' while they found a mild violation (stubbing a toe) to be funnier if they happened 'yesterday.'

To test the effect of social distance, the researchers conducted a third study in which they asked undergraduates to read status updates from strangers and from friends on a social networking website like Facebook. The college students reported that a stranger accidentally donating $1880 over text message (severe violation) was funnier than a friend doing so, but the $50 donation (mild violation) was funnier when a friend made the mistake.

A fourth study, which was conducted in HuRL, examined distance by manipulating whether an image was seen as hypothetical or real. Undergraduates were told that images — a man with a finger coming out of his eye and a man with a frozen beard — were either digitally altered or not. The students rated the more disturbing image as more humorous when they were told it was fake and they reported the less disturbing image as more humorous when they thought it was real.

The final study looked at the effect of perceived physical distance on humor. Participants saw one of the images from the fourth study; instead of being told that they were either real or fake, the size and position of the images were manipulated so that they looked like they were either close to or far away from the viewer. In line with previous findings, the more disturbing image was rated as funnier when it looked far away, and the less disturbing image was rated as funnier when it appeared closer.

The takeaway

Together, the five studies confirm that the space, time, social relationships, and hypotheticality that separate us from a violation interact with the severity of an event to influence how humorous a violation seems to us.

"These findings suggest that there's a real sweet spot in comedy — you have to get the right mix between how bad something is and how distant it is in order for it to be seen as a benign violation," says McGraw.

This may help to explain why The Onion was able to successfully joke about 9/11 even when most people considered it too soon to do so. The paper didn't satirize the victims of the tragedy — such a violation would have been far too extreme at the time — but instead satirized the terrorists (as one headline put it, "God Angrily Clarifies Don't Kill Rule"). And that means humorists can find ways to generate healthy laughter even about recent tragedies such as the Aurora shootings — as long as they land the joke in the comedic sweet spot.

Applying to college? Think before you tweet

Laura Gonzalez is a bit of a rare breed among college students because she has never shared anything regrettable on social media.

Unlike many of her peers, she refrains from sharing "T.M.I." about her relationship status and her weekend plans for one simple reason. She is looking for jobs.

"Facebook has become more of a branding tool more than anything else," said Gonzalez, a Wake Forest University senior who regularly shares on Facebook, Twitter and Tumblr. "Using social media is one way of putting out who you are, what your interests are, and showing how you can benefit the work force. But I always ask myself, 'What would a future employer think of this?'''

These days, employers are not the only ones using social media to evaluate their applicant pools. Higher education is increasingly getting in on the action, too. According to a 2011 Kaplan Test Prep survey, nearly a quarter of admissions officers use Facebook to help evaluate applicants, and 20 percent use Google.

Martha Allman, Wake Forest's Dean of Admissions, says social media offer additional communication channels for colleges and universities to get to know prospective students — but not in an attempt to act like Big Brother.

"Our admissions officers use Google, Facebook and YouTube more for good than anything else," she said. "In the past, we've used them to learn more about a service project student has written about, a musical group an applicant played in and an internship program an applicant referenced. Typically the results aren't surprising, but they can be reassuring."

Though there have been instances when her staff has found information online about a student that isn't flattering, she says there is never one determining factor in admitting students to Wake Forest.

"Anything negative we find typically confirms other suspicions we have already," Allman said.

According to a recent Pew Internet study, 80 percent of teens online use social media; of those, 93 percent are on Facebook. Because social media are an important part of today's teenage culture, Allman offers several tips to help students balance what she calls their "digital personae."

• Be careful what you put online – Don't post anything that you don't want an admissions officer to see.

• Know your privacy options – Privacy settings can change frequently, especially on Facebook. If you're tagged in a friend's photo, people in both of your networks can now see those. Instagram is even more open; default settings mean anyone can view your photos.

• Talk to your friends – Set ground rules about what types of status updates, photos and location based service updates you want to be tagged in. Chances are if they're applying to schools, they should think about their own profiles as well.

• Be yourself – Whether it's an essay, an interview or a Tweet, admissions officers are looking for the real you in all your communications.

"Wake Forest is one of many schools that uses Google and social media in its admissions process just as employers would when interviewing job applicants. Ultimately, we want to recruit talented individuals who would be a good fit for the campus community," Allman said. "If we need to follow up on an individual's experience or background, we might use social media, but we're also likely to use other means, too."

Gonzalez hopes this advice will her younger sister, a freshman in high school, before she gets caught up in the fun of sharing (or oversharing). Her sister doesn't use Facebook yet, but when she does, Gonzalez has her own personal tip.

"I will tell her not to put anything out there that she doesn't want our parents to see. It's that simple," she said. "Regardless of changing privacy settings, using good judgment will keep her in safe territory with admissions officers as well."

70% of women use contraceptives during their first sexual encounter, Spanish study suggests

 Contraceptive use in Spain during the first sexual encounter is similar to other European countries. However, there are some geographical differences between Spanish regions: women in Murcia use contraceptives less (55.8%) whereas women in the Basque Country use them more (76.7%).

Spanish researchers have analysed the prevalence of contraceptive use during the first sexual encounter over the last month in 5,141 sexually active women between the ages of 15 and 49 years through Spain's 17 autonomous communities.

"Bearing in mind the individual factors amongst women that determine contraceptive use, living in one autonomous community or another also has an influence," as explained by Dolores Ruiz Muñoz, researcher at the Public Health Agency of Barcelona and lead author of the study.

Published in the Health & Place journal, the results reveal that the prevalence of contraceptive use during the first sexual encounter is 70.4%. It varies in the different regions from 55.8% in Murcia to 76.7% in the Basque Country.

In this case, contraceptive use shows positive correlation in women with a university education and negative correlation amongst women from poor backgrounds.

Ruiz Muñoz points out that "contraceptive use during the first sexual encounter was more common amongst non-religious women in developed countries who had high educational attainment and their first sexual experience was between the ages of 18 and 19 years."

Furthermore, the prevalence of contraceptive use during the four weeks prior to the interview stood at 77.2%. Percentages varied from 70.9% in Navarra to 86.7% in Asturias, which suggested less difference between the different regions that in the case of the first sexual encounter.

The use of contraceptives during sexual relations in the month before the study was more common amongst younger women, those who live alone, those with higher educational attainment, those with children and those that had used contraceptives during their first sexual encounter.

"There are many factors that influence the correlation between the region and women at an intermediate level" continues the researcher. "These factors which influence the context must be taken into account to ensure all women throughout Spain have equal access to contraceptives regardless of their socio-economic level or the area where they live."

There are still inequalities

According to experts, contraceptives are the most effective way of preventing unplanned pregnancy and their use is widespread in Spain. Nonetheless, there are still some inequalities in their use.

In conclusion, this study highlights the importance of considering the social, economic and political characteristics of regions when designing administrative measures and promotion methods for contraceptive use.

Sex role stereotyping and prejudices in children explored

NewsPsychology (Jan. 27, 2012) — Girls are not as good at playing football as boys, and they do not have a clue about cars. Instead they know better how to dance and do not get into mischief as often as boys. Prejudices like these are cultivated from early childhood onwards by everyone. “Approximately at the age of three to four years children start to prefer children of the same sex, and later the same ethnic group or nationality,” Prof. Dr. Andreas Beelmann of the Fried­rich Schil­ler Univer­sity Jena (Germany) states.

This is part of an entirely normal personality development, the director of the Institute for Psychology explains. “It only gets problematic when the more positive evaluation of the own social group, which is adopted automatically in the course of identity formation, at some point reverts into bias and discrimination against others,” Beelmann continues.

To prevent this, the Jena psychologist and his team have been working on a prevention programme for children. It is designed to reduce prejudice and to encourage tolerance for others. But when is the right time to start? Jena psychologists Dr. Tobias Raabe and Prof. Dr. Andreas Beelmann systematically summarise scientific studies on that topic and published the results of their research in the science journal Child Develop­ment.

According to this, the development of prejudice increases steadily at pre-school age and reaches its highest level between five and seven years of age. With increasing age this development is reversed and the prejudices decline. “This reflects normal cognitive development of children,” Prof. Beelmann explains. “At first they adopt the social categories from their social environment, mainly the parents. Then they start to build up their own social identity according to social groups, before they finally learn to differentiate and individual evaluations of others will prevail over stereotypes.” Therefore the psychologists reckon this age is the ideal time to start well-designed prevention programmes against prejudice.

“Prevention starting at that age supports the normal course of development,” Beelmann says. As the new study and the experience of the Jena psychologists with their prevention programme so far show, the prejudices are strongly diminished at primary school age, when children get in touch with members of so-called social out groups like, for instance children of a different nationality or skin colour. “This also works when they don’t even get in touch with real people but learn it instead via books or told stories.” But at the same time the primary school age is a critical time for prejudices to consolidate. “If there is no or only a few contact to members of social out groups, there is no personal experience to be made and generalising negative evaluations stick longer.” In this, scientists see an explanation for the particularly strong xeno­phobia in regions with a very low percentage of foreigners or migrants.

Moreover the Jena psychologists noticed that social ideas and prejudices are formed differently in children of social minorities. They do not have a negative attitude towards the majority to start with, more often it is even a positive one. The reason is the higher social status of the majority, which is being regarded as a role model. Only later, after having experienced discrimination, they develop prejudices, that then sticks with them much more persistently than with other children. “In this case prevention has to start earlier so it doesn’t even get that far,” Beelmann is convinced.

Generally, the psychologist of the Jena University stresses, the results of the new study don’t imply that the children’s and youths attitudes towards different social groups can’t be changed at a later age. But this would then less depend on the individual development and very much more on the social environment like for instance changing social norms in our society. Tolerance on the other hand could be encouraged at any age. The psychologists’ “prescription”: As many diverse contacts to individuals belonging to different social groups as possible. “People who can identify with many groups will be less inclined to make sweeping generalisations in the evaluation of individuals belonging to different social groups or even to discriminate against them,” Prof. Beelmann says.

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The above story is reprinted from materials provided by Friedrich Schiller University Jena, via AlphaGalileo.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Tobias Raabe, Andreas Beelmann. Development of Ethnic, Racial, and National Prejudice in Childhood and Adolescence: A Multinational Meta-Analysis of Age Differences. Child Development, 2011; 82 (6): 1715 DOI: 10.1111/j.1467-8624.2011.01668.x

Facebook is a community

NewsPsychology (Jan. 25, 2012) — Researchers in Italy have used two high-speed computer algorithms to analyse the connections between a large sub-set of the more than half a billion users of the social networking site Facebook to reveal that the system has a very strong structure. The study, published in the International Journal of Social Network Mining, shows that Facebook has a well-defined community structure that follows a statistical power law in which there are a huge number of people with few connections and a much smaller number with a large number of connections.

Emilio Ferrara of the Department of Mathematics, at the University of Messina, has anonymised Facebook data and used two sophisticated algorithms to uncover the hidden network structure across Facebook’s millions of users. His research demonstrates that as with many social networks in the everyday world and networks found in nature, Facebook has the three common properties of such systems. First, it demonstrates the “small world” effect, known colloquially as “six degrees of separation” in which it is frequently possible to connect the majority of members, the nodes, of a network with all the other members through a small number of mutual friends or connections.

Secondly, Facebook follows the power law degree distribution where there are many users with a small number of connections. There are thus fewer and fewer users with more and more connections and only a very small number of people with a huge number of connections. Thirdly, Facebook rather obviously manifests as a community of interacting users rather than a collection of individuals.

One might imagine that so much is obvious given the popularity and activity of Facebook, which is the number one web destination and “application” for many millions of people. However, in order to prove that it is indeed a community-type network a statistical analysis of the type carried out by Ferrara was required. With the proof in hand, one might now investigate the structure of the Facebook network in more detail, apply the findings to other social networks, such as Twitter and LinkedIn in order to spot the differences and similarities with a view to informing those who operate and create such networks. The same research might also point the way to a better understanding of natural networks, such as offline human communities, insect colonies or even the spread of emergent diseases.

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Story Source:

The above story is reprinted from materials provided by Inderscience, via AlphaGalileo.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Emilio Ferrara. Community structure discovery in Facebook. International Journal of Social Network Mining, 2012; 1 (1): 67 DOI: 10.1504/IJSNM.2012.045106

Harnessing the predictive power of virtual communities

Scientists have created a new algorithm to detect virtual communities, designed to match the needs of real-life social, biological or information networks detection better than with current attempts. The results of this study by Lovro Šubelj and his colleague Marko Bajec from the University of Ljubljana, Slovenia have just been published in The European Physical Journal B.

Communities are defined as systems of nodes interacting through links. So-called classical communities are defined by their internal level of link density. By contrast, link-pattern communities — better suited to describe real-world phenomena — are characterised by internal patterns of similar connectedness between their nodes.

The authors have created a model, referred to as a propagation-based algorithm, that can extract both link-density and link-pattern communities without any prior knowledge of the number of communities, unlike previous attempts at community detection. They first validated their algorithm on several synthetic benchmark networks and with random networks. The researchers subsequently tested it on ten real-life networks including social (members of a karate club), information (peer-to-peer file sharing) and biological (protein-protein interactions of a yeast) networks. By this, it was found that the proposed algorithm detected the real-life communities more accurately than existing state-of-the-art algorithms.

They concluded that real-life networks appear to be composed of link-pattern communities that are interwoven and overlap with classical link-density communities. Further work could focus on creating a generic model to understand the conditions, such as the low level of clustering, for link-pattern communities to emerge, compared to link-density communities. The model could also help to explain why such link-pattern communities call the existing interpretation of small-world phenomena (six degrees of separation between nodes) into question.

Applications include the prediction of future friendships in online social networks, analysis of interactions in biological systems that are hard to observe otherwise, and detection of duplicated code in software systems.


Journal Reference:

  1. L. Šubelj, M. Bajec. Ubiquitousness of link-density and link-pattern communities in real-world networks. The European Physical Journal B, 2012; 85 (1) DOI: 10.1140/epjb/e2011-20448-7