Q&A: Why you have fewer friends than your friends do on Facebook.


With its one billion user mark hit yesterday, Facebook is closer to its mission of making the world more connected. And it appears to be literally changing the long-held idea of six degrees of separation, which states that everyone is no more than six steps from any other person on Earth. Researchers have found that within the Facebook community, that key number shrinks to just over four steps. This is just one finding of many coming out of an enormous study of 721 million active users on Facebook led by a group at Cornell University in collaboration with Facebook’s Data Science team. With such an embarrassment of social connection riches, the researchers have uncovered fascinating patterns and quirks of human and social behavior.

If you’ve felt not-as-popular as your friends on Facebook, you are right. Typically your friends will have about three times as many friends as you. Why? Well it has to do with math and statistics, and the research teams have proven that it plays out consistently within the Facebook network.

SmartPlanet spoke with Johan Ugander, a PhD candidate at Cornell’s Center for Applied Mathematics, and asked him to explain this friendship paradox, as well as reveal other findings about our social natures from this massive study.

SmartPlanet: One of the fascinating things is that, and you got this from the Facebook data, if all the people on a four-person list came from separate social groups (eg, from your high school, or work, or family) then the likelihood of someone being influenced by those people was more than twice as likely than if all the people were from the same social group (eg, all co-workers.)

Johan Ugander: Right. Facebook promises this opportunity in resolving incredibly data demanding questions in the social sciences. So we studied Facebook’s data and how millions of individuals are making decisions about joining Facebook.

And you found a very interesting quality of social decision-making, right?

Yes, we specifically looked at the invitation mechanism. Say you’re invited to Facebook, and they show you a number of different faces, faces of people already on Facebook. And the thing that really surprised us was that the dominant driving force was not how many unique social contacts that invited you.

It was some quality of those social contacts?

We found is that if there are two people that are part of this invitation community, and if those two people come from different social contexts, you’re fifty percent more likely to accept the invitation than if they’re from the same context.

So you mean that if two people are in the welcome invite to Facebook and one is from your high school context and the other is a co-worker you are twice as likely to join than if those two people were both family members?

Right. The basic motivation of this is that people that are from the same context are essentially redundant. So if your brother and sister are both recommending you a book, you don’t really take them as independent sources of information. But if you co-worker and your siblings recommend you a book, that’s a much stronger recommendation, because now it’s sort of reached you from two independent directions.

Fascinating. What are the practical implications of this?

With health practices, researchers are trying to figure out how to convince people to start using good health practices. Another obvious application is to help business spread ideas. And a recent study where the Facebook team studied the spread of voter participation, and it also showed that there is a big social component to voting.

Can you talk a bit more about Facebook’s research teams and what their motivations are?

Facebook has a research group called the Data Science team that helps to guide the product to its next levels. The Science Team has really grown since 2010.

And you started working with them in 2010 right?

One of the big papers that we put out in 2010 is this large-scale study where we asked a wide range of empirical questions about Facebook as a social network.

We were sitting on the largest social network data set, this treasure trove of data. So we asked a lot of the same questions social researchers have asked before, but now we were asking at a Facebook scale.

And what was one of those questions?

Well it has to do with the famous notion of six degrees of separation. With Facebook we have something resembling the complete graphic world, we have ten percent of the world’s population.   So how far apart are people?  Is it six degrees?

And was it?

No. In fact the average distance between any two people on Facebook was 4.74. But also we found these results had been shrinking over the the past three years, since 2007, the average distance between two people has been shrinking. This is related to Facebook’s mission of making the world more open and connected. A lot of people at Facebook were happy to see this.

Yes, Facebook has actually making the world smaller, by allowing relationships to flourish online, globally.

Another question that we wanted to ask was this notion of your friends always have more friends than you.

Right. That is fascinating, that no matter what, on Facebook your friends on average, will always have more friends than you have. It might seem depressing.

It’s called the “friendship paradox”. If you look across your friends, surprisingly often you have fewer friends than your friends do. And this is derived from a mathematical theorem.

And you found that the math worked in reality?

Yes we found that 93 percent of Facebook users have fewer friends than their friends. So it’s a mathematical fact, not something one should be depressed about.

Consider this metaphor: It happens for the same reason that when you go to the gym, you see only the fit people, and when you look at your friends on Facebook you see only people who are social.

You mentioned that Facebook users have an average number of 190 friends. But their friends average 635 friends. Now, when you say their friends average, are you talking about their total number of friends or are you talking about each individual friend added up? This is where it gets tricky.

Exactly, this is where it gets tricky. If you select a person at random and you get an average number of friends at 190. But if you look at a random friend of a random user, you’re biasing your selection towards people who have a lot of friends. You’re much more likely to hop to somebody who has a lot of paths leading to them. Somebody who has ten thousand friends is going to show up much more in your sample than somebody who only has two friends.

The gym metaphor helps here.

Right,  if you go to the gym you’re only seeing the people who go to the gym often. The couch potatoes are only going to the gym once a month, so on your average visit you’re not going to see them, whereas you’re going to see the person who’s there everyday.  And you might feel bad about your physique.

What would be a practical implication for the “friendship paradox”?

Well for Facebook there are implications. These factors of friends grow very quickly. Take a person with a 100 friends, and you think OK, their friends have about a hundred friends each, so you’d expect them to have 10,000 friends of friends, which is 100 x 100. But in reality a person with a hundred friends has twenty-seven thousand friends of friends, close to three times more than you would expect. This paper provided Facebook’s engineering people information on how some of these properties behave on Facebook.

What are Facebook’s goals with this research arm?

The Data Science team has an ambition to do a complete overhaul of these questions in social science and social psychology because it has a huge treasure trove of data. The research is useful for the design of products and recommendations that Facebook offers.

But on the academic side, the social science hypotheses that have been around for decades we can now get numbers for. And there’s a long list of studies that we’d like to run.

Source: Smart Planet.

In Berlin, crisis breeds creative business.


On a typical autumn evening at a low-lit, retrofitted bar in Berlin’s Prenzlauer Berg district, the cozy murmur of conversation and music seems to foreshadow the approaching cold months. But tonight, a mysterious group in black clothing pours through the front door, and one of them begins presenting patrons with small, white menus.

“Hi, my name is Serena,” the tall, dark-haired woman says with a smile. “I’m from Theater am Tisch (Theater at the Table), and this is the evening’s selection of dramatic pieces.”

The menu contains a list of scenes from cinema and stage, including one from the movie American Beauty, with monologues priced at 1.50 Euros and duets at 2 Euros per audience member. Serena nods in acknowledgement of some orders, situates empty chairs alongside the table, and whisks away to her colleagues at the other end of the bar.

Soon a man and woman take their seats at the table, placing a candle at its center. “The flame indicates the start of the scene,” they explain, lighting the candle.

The scene plays out believably: raised voices cause heads to turn, but only momentarily. The space of the tiny table seems to contain the captivating drama. Afterwards, thin but enthusiastic applause at the table is followed by handshakes and exchanges between the actors and their patrons.

It isn’t long before surrounding tables sneak a secondary peak at their menus and motion Serena over to place their orders.

Italian-born Serena Schimd launched Theater am Tisch in Berlin after moving to the city from Milan, where economic hard times put her previous employer out of business and made work generally difficult to find.

“We needed new opportunities,” Schimd says of herself and boyfriend Emiliano Saurin, a mobile web developer and entrepreneur.

“You can’t do the things you can do in Berlin in Milan; it’s too expensive. Here we can try things and see how they work without worrying about how to survive at the same time.”

Schimd and Saurin aren’t alone: Germany saw a drastic influx of immigrants from European Union countries in 2011, according to a report by the German Ministry of Migrants and Refugees. Immigration from places such as Greece increased as much as 90 percent from 2010.

Italian immigrants to Germany in 2011 ranked fifth in number among E.U. nations after those from Poland, Romania, Bulgaria and Hungary.

An interior designer by trade, Schimd says Theater Am Tisch started when she and some friends developed the business as part of a cultural association near Milan. With the project enjoying modest success in Milan after only a year, she immediately recognized a potential market in Berlin.

“There’s a lot of culture here,” she says. “You don’t have to ‘rent’ a bar to offer something like this; locale owners are happy to have you come in and try something new. Milan, on the other hand, is kind of a closed city. It’s a fashion hub, so there’s a lot of money there, and you have to pay to visit places, and you never know how much you’re going to earn.”

Schimd says Theater am Tisch – whose Berlin rendition includes nine actors from three countries — has been booked to perform at an upcoming awards show in Berlin, and that she is working to warm restaurants up to the concept.

“In Berlin, we’ve actually found it hard to get people to reserve performances because there’s often too many things to do in the city. That actually worked better in Milan, where this was more about food: people enjoyed the idea of sitting down to a dinner and ordering performances between courses.”

But Schimd says the project’s spontaneity has been surprisingly welcome in Berlin. She has even been able to raise prices in hip, upscale neighborhoods such as Prenzlauer Berg.

“We’re looking forward to the winter, when everyone is together inside bars and cafes in the evening and pleased to come across something new.”

Source: Smart Planet.

 

Does your school cause asthma?


A viral video got around last week that parodied Carly Rae Jepsen’s top-40 tune, “Call Me, Maybe.” It wasn’t all that funny, because environmentalists — like The League of Conservation Voters, which produced the mock music video — aren’t so humorous to begin with.

But the message behind “Test It, Maybe” was serious. The LCV was essentially asking why, since 1976, the Toxic Substance Control Act has put the burden of proof on the EPA that a given chemical is dangerous.

Instead, environmentalists and green building advocates are behind the new Safe Chemicals Act, which provides real health protections from industrial poisons. It passed a key Senate committee in July, but has languished since. We’re knee-deep in politics season, after all.

In synch with the times, recently a green building group launched a new “nutrition label” for buildings, a certification called Declare. Good news.

Greener buildings for less asthma

Remedying our chemical dependency, to turn a phrase, is an essential part of the green building movement. Architects who are into sustainability should look into Declare and learn about the Safe Chemicals Act — and sing loudly for its passage into law.

Perkins+Will is already on the job. “The Safe Chemicals Act is an essential piece of legislation for the building materials industry,” says Peter Syrett, an associate principal with the firm. He says his firm is “moving away from hazardous chemicals” and that this move can actually be profitable.

Last month the firm revised its own list of suspected chemical dangers in the built environment. By compiling peer-reviewed research, Perkins+Will lists 374 known asthmagens, as part of the firm’s Transparency Project. Their aim? Healthier schools, homes, workplaces and public places.

Buildings use a small portion of the 80,000 chemicals produced by U.S. industry. But of all those thousands, only 200 have been tested, wrote Margie Kelly in the Huffington Post.

The Red List

So except for killers like arsenic and the general category of volatile organic compounds (VOCs), its hard to know what asthmagens or similar suspected evils are inside a carpet, paint, wood, insulation or construction adhesive.

Even better than Transparency Project is the materials Red List, a project of the International Living Future Institute, which promotes super-green, ultra-healthy buildings through its “Living Building Challenge.” The group just launched their nicely concocted “nutrition label” for buildings, a project it calls Declare. (Visit http://www.declareproducts.com and have a look.)

The link between school buildings and asthma is a mysterious one, but many scientists have pointed to a causal connection.

Yet on EPA’s own website, the agency describes cigarette smoke, cockroach droppings and pet dander as possible causes — but not the 374 building compounds that architects regularly specify for new or renovated schools.

Science under attack

The reason is not because the chemicals are not known to affect asthma rates. It’s because the EPA would be vilified for mentioning it. And this weakened agency is supposed to fight back against a tide of products –many by large and powerful corporations — that use coal ash, Bisphenol A (BPA), polycholoroprene (better known as Neoprene), formaldehyde and various scary flame retardants.

Google is one of many companies opening lots of new office buildings that actively exclude these substances from their building specs. They are using the Red List to focus their efforts.

For now, architects and their clients need to study up and regulate building contents on their own.

Why? Because as Syrett recently told Forbes, “It’s a largely opaque market. When we buy a product from Home Depot or build anything, there’s no way for a consumer to know what a product is made of unless the manufacturer tells you.”

And almost none of them do.

Better for business

Maybe the Safe Chemicals Act will help modernize how we understand unregulated chemicals and how we build our schools and homes.

“We believe that companies should prove that the chemicals they use in products that they sell are safe,” says Christopher Miller, Corporate Consciousness, Seventh Generation.

One thing is certain: Just as the green-building movement has energized the construction industry, the Safe Chemicals Act would spur innovation in product and building design. It might even create new jobs and profits.

Don’t be scared of asthmagens. Get to know them, architects — and get them out of our schools.

Source: Smart Planet.

 

Save a bird: Turn off a light.


It’s that time of the year when migratory birds do their thing, so today’s a good day to draw attention to an alarming article I read over the summer about an alleged hazard that could put an abrupt end to a feathery flight.

According to an article on the Michigan Radio website, birds are fatally smashing into communication transmission towers because the red warning lights confuse their navigation systems.

If this sounds like a, er, lark, get this: About 7 million misguided birds die annually in tower collisions in the U.S. and Canada, according to a study by the U.S. Fish and Wildlife Service. Among the most susceptible: neotropical songbirds that migrate at night. A Cornell University photo that accompanied the Michigan Radio article shows a number of deceased warblers among the birds that hit a TV tower near Elmira, N.Y. during 1999’s Hurricane Floyd.

Of course, those tower lights serve a purpose. They prevent pilots from smacking into the structures.

But at the same time, they can trip up the birds’ natural guidance system, which relies on the stars and the sun. On a cloudy or foggy night when the stars don’t show but the tower lights do, things can go disastrously haywire. Bye-bye blackbird.

Red and steadily burning lights – those that don’t blink – are the biggest culprits, according to Joelle Gehring, a senior conservation scientist at Michigan State University. She ran a test on Michigan State Police towers that reduced collisions by between 50 and 70 percent when the police turned of the constantly lit lights.

The Federal Aviation Administration says that on some towers, operators could turn off steady lights or replace them with blinkers without jeopardizing pilot safety – as long there were ample flashing lights, the article states.  Sounds like a solution that could fly.

Source: Smart Planet.

 

Structural and biochemical characteristics of arterial stiffness in patients with atherosclerosis and in healthy subjects.


Arterial stiffness is an independent predictor of vascular morbidity and mortality in patients with atherosclerosis. Angiographic score (ASc) reflects severity of atherosclerosis in patients with peripheral arterial disease (PAD). Osteopontin (OPN) and oxidized low-density lipoprotein (oxLDL) are involved in the pathogenesis of atherosclerosis. The aim of the present study was to evaluate the association between arterial stiffness, ASc, serum OPN and oxLDL in patients with symptomatic PAD, and in clinically healthy subjects. We studied 79 men with symptomatic PAD (mean age 64±7 years) and 84 healthy men (mean age 63±8 years). Calculation of the ASc was based on severity and location of atherosclerotic lesions in the arteries of the lower extremities. Aortic pulse wave velocity (aPWV) was evaluated by applanation tonometry using the Sphygmocor device. Serum OPN and oxLDL levels were determined by enzyme-linked immunosorbent assay. The aPWV (10±2.4 VS. 8.4±1.7 (m s−1); P<0.001), OPN (75 (62.3–85.8) VS. 54.8 (47.7–67.9) (ng ml−1); P<0.001) and oxLDL (67 (52.5–93.5) VS. 47.5 (37–65.5); P<0.001) were different for the patients and for the controls. In multiple regression models, aPWV was independently determined by ASc, log-OPN, log-oxLDL and estimated glomerular filtration rate in the patients (R2=0.44; P<0.001) and by log-OPN, log-oxLDL, age and heart rate in the controls (R2=0.38; P<0.001). The independent relationship of a PWV with serum levels of OPN and oxLDL in the patients with PAD and in the controls indicates that OPN and oxLDL might influence arterial stiffening in patients with atherosclerosis and in clinically healthy subjects.

Source: Hypertension Research/nature.

24-h ambulatory recording of aortic pulse wave velocity and central systolic augmentation: a feasibility study.


We assessed the feasibility of ambulatory pulse wave analysis by comparing this approach with an established tonometric technique. We investigated 35 volunteers (45.6 years; 51.0% women) exclusively at rest (R study) and 83 volunteers (49.9 years; 61.4% women) at rest and during daytime (1000–2000 h) ambulatory monitoring (R+A study). We recorded central systolic (cSP), diastolic (cDP) and pulse (cPP) pressures, augmentation index (cAI) and pulse wave velocity (PWV) by brachial oscillometry (Mobil-O-Graph 24h PWA Monitor) and radial tonometry (SphygmoCor). We applied the Bland and Altman’s statistics. In the R study, tonometric and oscillometric estimates of cSP (105.6 vs. 106.9 mm Hg), cDP (74.6 vs. 74.7 mm Hg), cPP (31.0 vs. 32.1 mm Hg), cAI (21.1 vs. 20.6%) and PWV (7.3 vs. 7.0 m s−1) were similar (P0.11). In the R+A study, tonometric vs. oscillometric assessment yielded similar values for cSP (115.4 vs. 113.9 mm Hg; P=0.19) and cAI (26.5 vs. 25.3%; P=0.54), but lower cDP (77.8 vs. 81.9 mm Hg; P<0.0001), so that cPP was higher (37.6 vs. 32.1 mm Hg; P<0.0001). PWV (7.9 vs. 7.4 m s−1) was higher (P=0.0002) on tonometric assessment. The differences between tonometric and oscillometric estimates increased (P0.004) with cSP (r=0.37), cAI (r=0.39) and PWV (r=0.39), but not (P0.17) with cDP (r=0.15) or cPP (r=0.13). Irrespective of measurement conditions, brachial oscillometry compared with an established tonometric method provided similar estimates for cSP and systolic augmentation, but slightly underestimated PWV. Pending further validation, ambulatory assessment of central hemodynamic variables is feasible.

Source: Hypertension Research/nature.

Study finds rise in gay characters on network TV.


The number of gay and bisexual characters on scripted broadcast network TV is at its highest-ever level in the season ahead, according to the Gay & Lesbian Alliance Against Defamation. The total on cable television is also going up.

The 17th-annual “Where We Are on TV” report released Friday by GLAAD found that 4.4 percent of actors appearing regularly on prime-time network drama and comedy series during the 2012-13 season will portray lesbian, gay, bisexual or transgender characters. This is up from 2.9 percent in 2011, which saw a dip in what had been a growing annual trend.

The study reviewed 97 scripted TV programs scheduled to air in the upcoming season on the broadcast networks, counting a total of 701 series regular characters. The study found that 31 of them are LGBT characters.

ABC has the highest amount with 10 out of 194, or 5.2 percent, of their regular characters identified as LGBT.

After leading last year, Fox ranks second with six LGBT characters out of 118 total series regulars, or 5.1 percent.

CBS was saluted as the most-improved network, with four out of 142 LGBT series regulars, or 2.8 percent, up from 0.7 percent last year. Among CBS’s new fall series is “Partners,” a comedy about two childhood friends and business partners, one of whom is gay and in a relationship. The network’s lineup represents “an authentic and conscious effort by CBS to improve its diversity,” the study said.

Regular gay and lesbian characters on what the study termed “mainstream” cable television has also risen this season to 35, up from 29 last season.

Among those networks, Showtime leads with 12 LGBT characters. The study also cited HBO, FX, Adult Swim, ABC Family, MTV, Syfy and TeenNick.

The HBO drama “True Blood” remains cable’s most inclusive series, featuring six LGBT characters.

On broadcast TV, male LGBT characters continue to outweigh female characters, 55.5 percent to 44.5 percent, the study found.

Compared to last year, African-American representation has grown from 9.9 percent to 12 percent, while Hispanic representation has decreased from 5.6 percent to 4.1 percent.

“It is vital for networks to weave complex and diverse story lines of LGBT people in the different programs they air,” said GLAAD President Herndon Graddick. “More and more Americans have come to accept their LGBT family members, friends, co-workers and peers, and as audiences tune into their favorite programs, they expect to see the same diversity of people they encounter in their daily lives.”

Source: ABC news.

C-reactive protein (CRP) gene polymorphisms, CRP levels and risk of incident essential hypertension: findings from an observational cohort of Han Chinese.


C-reactive protein (CRP), an acute phase reactant and marker of inflammation, has been shown to be associated with CRP genetic variants and incident hypertension, but it is unclear whether this link is causal. We therefore conducted a prospective, nested case–control study to examine the relationship between single-nucleotide polymorphisms (SNPs) within the CRP gene, circulating CRP levels and the development of hypertension. Plasma CRP levels and the genotypes of eight SNPs were determined in 2000 unrelated Shanghai residents, including 908 hypertensive individuals and 1092 normotensive individuals. Among the 1092 normotensives, 968 subjects were followed up for 2 years, during which 71 developed hypertension. Plasma CRP levels were independently associated with the development of hypertension in the follow-up study (odds ratio per quartile=1.64; 95% confidence interval: 1.18–2.26; P<0.001). The minor alleles of rs1130864 (P<0.001) and rs3093059 (P<0.001) were significantly associated with elevated CRP levels, and the minor alleles of rs1205, rs1800947 and rs2246469 (all P<0.001) were associated with decreased CRP levels. A haplotype-based analysis strengthened the results of single-locus analysis. However, none of the SNPs or haplotypes was significantly associated with blood pressure, incident hypertension or changes between baseline and follow-up blood pressure levels. Taken together, our findings demonstrated that plasma CRP levels were substantially associated with common genetic variants in the CRP gene and could predict the development of hypertension. However, the relationship between genotype and CRP levels was not associated with a change in hypertension risk.

Source: Hypertension Research/nature.

 

The North Face Powder Guide ABS vest: peak performance.


Thrill-seekers choose backcountry and sidecountry skiing as winter sport, but rugged climbs and steep slopes in uncharted territory can be dangerous without the right gear. The North Face offers a life-saving tool packed into a vest.

The Powder Guide ABS vest is a nitrogen-based avalanche airbag system that the American outdoor apparel company designed with German manufacturer ABS. When deployed, the vest’s two airbags help keep you at the surface when you’re in danger of being buried in tumbling snow. The bags also act as buffers, protecting your head, neck and back from trees or large rocks if you’re swept off your feet.

The vest has eight front pockets to fit all of your gear, and it’s big enough to wear over your ski jacket — just in case you want to turn an Alpine vacation into a real adventure.

Source: Smart Planet.

Stroke patients with cerebral microbleeds on MRI scans have arteriolosclerosis as well as systemic atherosclerosis.


Cerebral microbleeds (CMBs) are recognized as a manifestation of arteriolosclerosis in cerebral small vessels. However, little is known regarding whether stroke patients with CMBs often have systemic atherosclerosis. The aim of the present study was to elucidate this issue using the cardio–ankle vascular index (CAVI), a new index of systemic atherosclerosis, in acute ischemic stroke patients. We prospectively studied 105 patients (71 males, median age=70.0 years) with acute ischemic stroke. All of the patients were examined using T2*-weighted gradient echo magnetic resonance imaging (MRI) to look for and assess the CMBs and using fluid-attenuated inversion recovery to evaluate white matter hyperintensity (WMH). We assigned the patients into CMB and non-CMB groups and compared the clinical characteristics of these groups. The factors associated with CMBs were investigated using multivariate logistic regression analysis. T2*-weighted gradient echo MRI revealed CMBs in 47 patients (44.8%) and no CMBs in 58 patients (55.2%). The CAVI was significantly higher in the CMBs group (10.5 vs. 8.6, P<0.001). In the multivariate logistic regression analysis, CAVI per one point increase (odds ratio (OR), 1.50; 95% confidence interval (CI), 1.12–2.00; P=0.006), advanced WMH (OR, 4.78; 95% CI, 1.55–14.74; P=0.006) and impaired kidney function (OR, 3.31; 95% CI, 1.16–9.81; P=0.031) were independent factors associated with the presence of CMBs. A high CAVI was independently associated with CMBs in patients with acute ischemic stroke. Our results indicated that ischemic stroke patients with CMBs may have cerebral arteriolosclerosis as well as systemic atherosclerosis.

Source: Hypertension Research/nature.