Progress Daily

Since 1948 three generations of residents in Framingham have participated in regular medical examinations. A new study (”Alone in the crowd: The structure and spread of loneliness in a large social network”; .pdf file here) by John Cacioppo that uses Framingham to analyse loneliness has found that it spreads very much like a communicable disease.

Participants in the study were routinely asked to list people who would probably know their whereabouts in the next 2 to 4 years, & were asked to describe their relationship with each person as friend, spouse, sibling, neighbour or colleague. Between 1983 and 2001 participants were regularly asked to state how many days a week they felt certain feelings, such as loneliness.

Analyzing this data, the researchers found that loneliness formed in clusters of people, and that once one person in a social network started expressing feelings of loneliness, others within the same network would start to feel the same way. Those who had immediate contact with lonely people were around 50% more likely than average to feel lonely themselves. In people who knew people who had direct contact with lonely people, the figure was 25%. Those with three degrees of separation showed roughly a 10% increase.

The effects were more noticeable among friends than family, and stronger among women than men.

“Alone in the crowd,” The Economist

Research by Emma Cohen (”Rowers’ high: behavioural synchrony is correlated with elevated pain thresholds“), suggests that training in a synchronised group may heighten tolerance for pain, & allow people to train longer.

The researchers got 12 members of Oxford’s heavyweight squad to row on machines in four 45-minute sessions over two weeks. In two sessions they rowed in complete isolation and in the others in groups of six, perfectly synchronised. Immediately following each session they deduced pain tolerance by gradually tightening a cuff around each rower’s arm. When he said “now” they stopped squeezing and noted the pressure.

The rowers’ pain thresholds were significantly higher following the group sessions. This was despite nearly identical power outputs in all four tests and efforts to control for possible confounding variables, such as the time of day.

“Fitter with friends,” The Economist

Non-kin altruism among non-human animals is rare, & altruism fares poorly in computer simulations — when altruistic individuals emerge in a community characterized by self-interested behavior, selfishness triumphs.

Group selection could explain the prevalence of human altruism but probably only if the ancestral environment included high levels of violence and inbreeding.

Sam Bowles showed in 2006 that genetic analyses of tribes still living a Stone Age life suggests there was enough inbreeding to make group competition a driver of genetic change.

In ancient graves excavated previously, Bowles found that up to 46% of the skeletons from 15 different locations around the world showed signs of a violent death. More recently, war inflicted 30% of deaths among the Ache, 17% among the Hiwi, & just 4% among the Anbara. Combat between groups accounted for about 14% of all deaths in these hunter-gatherer societies.

After estimating the rate that altruism would reduce an individual’s chances of reproducing, Bowles plugged the numbers into a model of intergroup competition where an individual’s altruism would also improve a group’s chances of combat triumph. In the absence of war, a gene imposing a self-sacrificial cost of as little as 3% in forgone reproduction would drop from 90% to 10% of the population in 150 generations. Bowles predicts that much higher levels of self-sacrifice — up to 13% in one case — could be sustained if warfare were brought into the equation.

“Did Warfare Among Ancestral Hunter-Gatherers Affect the Evolution of Human Social Behaviors?” By Samuel Bowles

“Altruism’s Bloody Roots,” by Brandon Keim

“Ancient warfare: Fighting for the greater good,” by Ewen Callaway

“Blood and treasure,” The Economist

A 10-year Australian study (”Effect of social networks on 10 year survival in very old Australians“) found that older people with a large circle of friends were 22% less likely to die during the study period than those with fewer friends.

A large 2007 study (”The Spread of Obesity in a Large Social Network over 32 Years“) showed an increase of nearly 60% in the risk for obesity among people whose friends gained weight.

In 2008, Harvard researchers reported that strong social ties could promote brain health as we age (”Effects of Social Integration on Preserving Memory Function in a Nationally Representative US Elderly Population“). Over a 6-year period, memory among the least integrated declined at twice the rate as among the most integrated.

In 2006, a study (”Social Networks, Social Support, and Survival After Breast Cancer Diagnosis“) of nearly 3,000 nurses with breast cancer found that women without close friends were four times as likely to die from the disease as women with 10 or more friends. Proximity and the amount of contact with a friend wasn’t associated with survival, nor was having a spouse.

In 2008, researchers studied 34 college students (”Social support and the perception of geographical slant“), taking them to the base of a steep hill and fitting them with a weighted backpack. They were then asked to estimate the steepness of the hill. Some participants stood next to friends during the exercise, while others were alone. The students who stood with friends gave lower estimates of the steepness of the hill. And the longer the friends had known each other, the less steep the hill appeared.

“What Are Friends For? A Longer Life,” by Tara Parker-Pope

People who are perceived to be trustworthy are more likely to have a higher credit score and pay lower interest rates on loans, and are less likely to default, according to a study by Jefferson Duarte & Stephan Siegel (”Trust and Credit“).

The researchers studied members of Prosper.com, where people looking for loans are matched up with individual lenders.

Each Prosper.com loan applicant submitted a profile which included credit and work history, education level, income and an optional photograph of themselves for lender review.

More than 6,800 loan applications, 2,600 loans and 12,000 photographs were used in the study.

Duarte hired a team of 25 people to rate the applicants’ trustworthiness on a scale of 1 to 5 using only the photographs of the borrowers. The team also judged the probability that the borrowers would repay a $100 loan.

Those judged to be trustworthy were more likely to get a loan from Prosper.com lenders and tended to have a credit score about 20 points higher than those determined to be untrustworthy.

“Untrustworthy” borrowers were 7% more likely to default on their loan than a perceived trustworthy borrower with the same credit score.

The researchers controlled for race, age, gender, obesity, attractiveness and education, employment status, income and homeownership.

“Creditworthiness may be linked to looks,” by Rebekah Kebede

Sean McCrea, Nira Liberman, & Yaacov Trope researched procrastination & found that people tend to act in a timely way when given concrete tasks but dawdle when they view them in abstract terms (”Construal Level and Procrastination“).

The researchers conducted 3 studies.

(1) They recruited 34 students who were offered €2.50 ($3.30) for completing a questionnaire within the subsequent three weeks. Half of the students were then sent an email asking them to write a couple of sentences on how they might go about various activities, such as opening a bank account or keeping a diary. The others were asked to write about why someone might want to open a bank account or keep a diary.

(2) They recruited 50 students, who were offered the same sums and timespans as the first lot. Half of these students were asked to provide examples of members of a group, for example, naming any type of bird. The task was inverted for the other students, who were asked to name a category to which birds belong.

(3) They asked 51 students, who were again offered cash and given a deadline, to examine a copy of “La Parade” by Georges Seurat. Half were given information about pointillism, the technique Seurat used to create the impression of solid colours from small dots of paint. The others were told that the painting was an example of neo-impressionism in which the artist had used colour to evoke harmony and emotion. Both groups were then asked to rate the importance of colour in 13 other works of art.

In all 3 studies, those who were presented with concrete tasks and information responded more promptly than did those who were asked to think in an abstract way. Moreover, almost all the students who had been prompted to think in concrete terms completed their tasks by the deadline while up to 56% of students asked to think in abstract terms failed to respond at all.

“Motivating minds,” The Economist

Less than 1% of private gifts to charity are anonymous.

Dan Ariely, Anat Bracha, and Stephan Meier (”Doing Good or Doing Well? Image Motivation and Monetary Incentives in Behaving Prosocially“) conducted an experiment where the number of times participants clicked an awkward combination of computer keys determined how much money was donated on their behalf to the American Red Cross. Since 92% of participants thought highly of the Red Cross, giving to it could reasonably be assumed to make people look good to their peers. People were randomly assigned to either a private group, where only the participant knew the amount of the donation, or a public group, where the participant had to stand up at the end of the session and share this information with the group. Participants exerted much greater effort in the public case: the average number of clicks, at 900, was nearly double the average of 520 clicks in the private case.

The researchers added to their experiment a monetary reward for participants. In private, being paid to click increased effort from 548 clicks to 740, but in public, there was next to no effect. Presumably, for the public clickers, the added motivation of financial reward was offset by the reduced appearance of generosity.

“Looking good by doing good,” The Economist

Wen Zhou & Denise Chen speculated that if humans produce and respond to sweat pheromones, then a woman should respond to a guy’s sweat when sexually aroused differently than she does to his normal sweat.

The researchers asked 20 heterosexual guys to put pads in their armpits as they watched pornographic videos and became aroused (verified by electrodes). Later, they collected the sweat they produced when they weren’t aroused. (See “Encoding Human Sexual Chemosensory Cues in the Orbitofrontal and Fusiform Cortices“)

The researchers then recruited 19 women to smell the men’s pads while undergoing (fMRI) brain scans. The sexual sweat, but not the normal sweat, activated the right orbitofrontal cortex and the right fusiform cortex, brain areas that help us recognize emotions and perceive things, respectively. Both regions are in the right hemisphere, which is generally involved in smell, social response, and emotion.

“Women Can Smell a Man’s Intentions,” Melinda Wenner

Nicholas A. Christakis & James H. Fowler studied about 4,700 people, followed from 1983 to 2003 as part of the Framingham Heart Study. (See “Dynamic spread of happiness in a large social network”; .pdf file here.) These subjects were embedded in a larger network of about 12,000 people; they had an average of 11 connections to others in the social network (including to friends, family, co-workers, and neighbors); and their happiness was assessed every few years using a standard measure.

The researchers found that social networks have clusters of happy and unhappy people within them that reach out to three degrees of separation. A person’s happiness is correlated with the happiness of their friends, their friends’ friends, and their friends’ friends’ friends. Happy people tended to be located in the center of their social networks and to be located in large clusters of other happy people. Each additional happy friend increased a person’s probability of being happy by about 9%. (For comparison, having an extra $5,000 in income — in 1984 dollars — is estimated to increase the probability of being happy by about 2%.)

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In an unpublished follow-up study, the researchers examined a group of about 1,700 college students on Facebook. They coded who appeared in photographs with whom. The average student had over 110 friends on Facebook, but they had an average of only six “picture friends” (i.e., people close enough that they tagged the student).

They then coded whether the students were smiling in their profile photographs, and mapped the network of students and their picture friends, making note of who was smiling and who was not.

The figure above is a map of part of this Facebook network in 2007. It contains about 350 students, each represented by a node; each line between two nodes indicates that the connected individuals were tagged in a photo together. Students who were smiling (and who were immediately surrounded by smiling people in their network) are colored yellow. Students who were frowning (and who are immediately surrounded by such serious looks) are colored blue. Shades of green indicate a mix of smiling and non-smiling friends.

The blue nodes and the yellow nodes strongly cluster together. Statistical analysis of the network shows that people who smile tend to have more friends (smiling is correlated with an average of one extra friend, which is significant, since the average person has only about 6 close friends). Those who smile are measurably more central to the network.

“Social Networks & Happiness“

The Internet gives access to a huge market at very low marginal cost. This creates the possibility of success at very low participation rates.

Wikipedia works despite the fact that only about 0.01% of readers regularly contribute material. With 680 million annual visitors, that’s still 75,000 active contributors — who have created 10 million articles.

YouTube works with just 0.1% of users uploading their own videos.

And spammers can make a fortune with response rates of 0.00001%.

“The miraculous power of scale,” by Chris Anderson