The science of friendship

There is an interesting article by Robin Dunbar in The New Scientist: Dunbar’s Number was named after Robin, from his theorizing that humans only had the brain capacity to manage roughly 150 relationships, although depending on gender, social skills and personality, this number could vary from 100-250.  Dunbar observes that communication often breaks down when one exceeds 150 individuals (as evidenced in the Crimean War by the Charge of the Light Brigade) and the modern military and businesses only exceed these limits through strict hierarchies.

Dunbar theorizes that language, laughter and communal music-making evolved as a way to stay connected to a larger group of individuals than possible through physical acts like grooming. Dunbar: “[N]ot only can we speak to many people at the same time, we can also exchange information about the state of our networks in a way that other primates cannot. Gossip, I have argued, is a very human form of grooming.”  Christakis and Fowler (in the excellent book Connected) note that “…language is a less yucky and more efficient way to get to know our peers since we can talk to several friends at once but only groom them one at a time.  In fact, in a conversation with a small group, we can assess the behavior, health, aggressiveness, and altruism of several individuals simultaneously.  Plus, we can talk to someone else while engaged in another activity, like foraging for food in a refrigerator.”  Christakis and Fowler note how radical the idea is that language evolved not primarily as a way to exchange information but to maintain group cohesion.   “Dunbar estimates that language would have to be 2.8 times more efficient than grooming in order to sustain the [average] group size seen in humans” (one speaker per 2.8 listeners).

While language may have originally evolved, as per Dunbar, to maintain a slightly larger group size, once developed it was in principle possible to use language to maintain social relations on a tribal or national level.

A few other excerpts from Dunbar’s article:

Group living needn’t tax your intelligence too much. In a loose herd, cues such as body size or aggressiveness may be enough to judge whether you should challenge or steer clear of another individual. In bonded networks, however, you need to know each member’s personal characteristics and those of the friends and relations that might come to their aid. Keeping track of the ever-changing web of social relationships requires considerable mental computing power.

As a reflection of this, there is a correlation between the size of a species’ brain– in particular its neocortex– and the typical size of its social groups. In other words, brain size seems to place a limit on the number of relationships an individual can have. This link between group size and brain size is found in primates and perhaps a handful of other mammals that form bonded societies such as dolphins, dogs, horses and elephants. In all other mammals and birds, unusually large brains are found only in species that live in pair-bonded (monogamous) social groups.

As group size increases so too does the number of relationships that need servicing. Social effort is not spread evenly. Individuals put most effort into their closest relationships to ensure that these friends will help out when they need them. At the same time they maintain the coherence of the group. As a result, social networks resemble a nested hierarchy with two or three best friends linked into larger groupings of more casual friends, and weaker relationships bonding the entire group. This hierarchy typically has a scaling ratio of three– each layer of decreasing intimacy is three times larger than the one before it….

HUMAN SOCIAL NETWORKS

Our social networks can have dramatic effects on our lives. Your chances of becoming obese, giving up smoking, being happy or depressed, or getting divorced are all influenced by how many of your close friends do these things. A good social network could even help you live longer since laughing with friends triggers the release of endorphins, which seem to “tune” the immune system, making you more resilient to disease. So what factors influence the form and function that our social networks take.

In traditional societies, everyone in the community is related to everyone else, either as biological relatives or in-laws. In post-industrial societies this is no longer true– we live among strangers, some of whom become friends. As a result, our social circles really consist of two separate networks– family and friends– with roughly half drawn from each group.

Because the pull of kinship is so strong, we give priority to family, choosing to include them in our networks above unrelated individuals. Indeed, people who come from large extended families actually have fewer friends. One reason we favour kin is that they are much more likely to come to our aid when we need help than unrelated individuals, even if these are very good friends.

Family and friend relationships differ in other important ways, too. One is that friendships are very prone to decay if untended. Failure to see a friend for six months or so leaves us feeling less emotionally attached to them, causing them to drop down through the layers of our network hierarchy. Family relationships, by contrast, are incredibly resilient to neglect. As a result, the family half of our network remains constant throughout most of our lives whereas the friendship component undergoes considerable change over time, with up to 20 per cent turnover every few years.

More than 60 per cent of our social time is devoted to our five closest friends, with decreasing amounts given over to those in the layers beyond, until at the edge of the 150 layer are people we perhaps see once a year or at weddings and funerals. Nevertheless, the outer reaches of our social networks have a positive role to play. The sociologist Mark Granovetter at Stanford University in California has argued that these weak links in our social networks are especially useful in the modern world. It is through this widespread network of contacts that we find out about job vacancies and other economic or social opportunities. More importantly, perhaps, 70 per cent of us meet our romantic partners through these contacts.

Read “Getting Connected” by Robin Dunbar (New Scientist, 4/3/12)

Homeownership and Civic Engagement

There is a section in Bowling Alone on how homeowners are more involved civicly than renters. Barry Bluestone, Dean of the School of Public Policy and Urban Affairs, at Northeastern University, was speaking to the Harvard Kennedy School Inequality Program today on “Is Homeownership Now Just a Dream?” Among discussions of who benefits from homeownership, he discussed whether we should support it and raised the issue of whether homeowners are better citizens, and if so, is it just due to their longer tenure in neighborhoods. Excerpt from his draft paper:

“To test the assertions made in the literature, we conducted our own analysis using data collected through the National Survey of Families and Households (NSFH) fielded in 2001/2002….In our analysis of the NSFH data, it was possible to investigate the impact of homeownership on a range of factors including the respondent’s optimism about their own life circumstances; on church attendance; on getting together with neighbors; on participation in group recreational activities; on the time they spend in local sports, hobby and discussion groups; and in the number of times they participate in the activities of local service clubs, fraternal organizations and political groups….  Essentially, this [our] analysis asks the following question: if renters had the same income, age, education, and residential tenure as homeowners, would they be as optimistic about their own lives and be as civically-engaged as exisitng homeowners?  Again, is there any benefit to homeownership per se? The results of this new analysis point to a number of individual and social benefits that accrue to homeowners even when compared to renters who have lived in the same place for nearly ten years and have equivalent social-economic status (SES) – income, education, and age.   On the one hand, the analysis finds no difference between homeowners and renters in church attendance, in getting together with friends, or in participating in group recreational activities.  On the other, homeowners tend to be more optimistic about their own futures, they participate more often in local sports and discussion groups, and most importantly they are more civically engaged in service organizations, fraternal groups, and political organizations… Before controlling for housing tenure and SES, 48.3% of homeowners report that they participated in sports, hobby, or discussion groups at least once a year; only 37.9% of renters reported such.  After controlling for these factors, the probability of renters participating in these activities increases to 39.8%.  Hence, homeownership per se appears to boost such participation by 8.5 percentage points or by more than 21 percent. Before controlling for housing tensure and SES, 37.5% of homeowners but only 27.2% of renters responded that they participated at least once a year in service clubs, fraternal organizations, or political groups.  After controlling for tenure and SES, renter participation appears to increase to 31.5%, still 6 percentage points less than homeowners.  That is, homeowners are 19 percent more likely to be active in these groups.

Bluestone seems sympathetic to homeownership.  His analysis is interesting but despite his effort to be “fair”, he likely overcontrols since he makes the highly unlikely assumption that one could have considerable number of renters with the same tenure as homeowners. One thing that Bluestone didn’t examine is how renters and buyers differ in their future intentions of rootedness and geographic mobility: only 25% of homeowners, when we conducted research for Bowling Alone, expected to move in the next five years versus two-thirds of renters.  If we had policies in America that left us with far more renters, it seems wishful thinking to imagine that most of them would remain in community for as long as the owners. And thus even on the measures where Bluestone doesn’t find that homeownership is associated with higher levels of engagement after his demographic controls (namely, socializing and  church attendance), homownership probably really is still associated with higher socializing and church attendance.  Homeownership works to increase rootedness (partly psychologically and partly financially) and this rootedness increases socializing and church attendance.

Bluestone also relayed an interesting and telling anecdote  about his hometown of Detroit.  Albert Cobo (Mayor of Detroit in the early 1950s) used the power of eminent domain to raze a poor community in downtown Detroit to prepare for highway expansion that never occurred.  After the highway fell through, African-Americans’ hopes that the razed area would soon be rebuilt,  the suburbs of Detroit were developed, but the area razed by Cobo remained vacant.  Eventually the UAW developed a significant tract of housing in the razed area but insisted that all the homes be rental units.  Edison developed a community across the street, even hiring the same architect to give the other community the same look and feel.  Bluestone notes that while these areas (the UAW rental tract and the Edison ownership tract) attracted similar residents, the Edison (home-owned) units have remained in much better condition as the owners have worked to preserve their investments and volunteered for neighborhood groups that preserved the more general environment.  My guess, although Bluestone didn’t say this, is that residential tenure was also much longer in the Edison ownership tract than in the UAW rental one.

U.S. Government expands social capital measures

Flickr/citychiccountrymouse

The Census through the Bureau of Labor Statistics (BLS) is expanding the items that it asks about civic engagement and social capital.

On the November 2011 Current Population Survey (CPS) supplement, BLS will now ask about:

• Voting in local elections (such as mayor or school board)
• Frequency of using the internet to express opinions about political or community issues
• Frequency of communicating with family and friends
• Trust of neighbors
• Confidence in institutions (specifically corporations, the media and public schools)

These metrics will show up in the 2012 Civic Life in America report.

Many other measures of social capital and civic engagement are already being surveyed by BLS on the November supplement (more here), and BLS also asks on their September supplement metrics on volunteering, attendance at public meetings, and whether Americans have worked with neighbors to fix/improve something.  The volunteering measures are reported by CNCS on the Volunteering in America website.

See “Census to collect new social capital measures”

Read earlier post “Advances in social capital measurement“

Praying alone is no fun; having friends at church makes you happier

Flickr photo by Shavar Ross

[Also cross-posted on the American Grace Blog]
American Grace research team members Chaeyoon Lim and Robert Putnam have an article in the prestigious American Sociological Review demonstrating that religion actually makes you happier and it works through having close friends at church.

“Our study offers compelling evidence that it is the social aspects of religion rather than theology or spirituality that leads to life satisfaction,” said Chaeyoon Lim, assistant professor of sociology at the Univ. of Wisconsin-Madison, who led the study. “Listening to sermons or praying is not enough.  In particular, we find that friendships built in religious congregations are the secret ingredient that makes people happier.”

A host of studies have found a correlation between happiness and religiosity, but they suffered from the vulnerabilities of any single shot survey. Was religiosity truly causing happiness, was happiness causing greater religiosity, or was some third factor responsible (say an extroverted gene that made people both happier and more likely to go to “church”)? With the large nationally representative Faith Matters surveys, which interviewed the same Americans twice in a 6-9 month period, Lim and Putnam demonstrate that increased church attendance over that 6-9 month period increases life satisfaction. Surprisingly, they find that more overtly religious factors like theology (e.g., belief about the type of God or the afterlife or what religion you belong to) and private religious practices (e.g., experiencing God’s presence in your life or saying Grace or frequency of prayer) did not predict greater life satisfaction.

So what explained the power of religious attendance? Lim and Putnam found that it was having close friends in one’s house of worship. While friends in general cause people to have greater life satisfaction, friends at church serve as “super-charged” friends, with an even stronger impact on life satisfaction than secular friends.

It’s not clear exactly why close friends at church have such strong power. Lim and Putnam speculate that these church friends anchor “a strong sense of belonging in these religious communities” and provide parishioners with “morally-infused social support. In other words, if one seeks life satisfaction, it is neither faith nor communities alone that are important, but communities of faith. For life satisfaction, praying together seems better than either bowling together or praying alone. These findings suggest that religious leaders should invest more of their time, treasure and talent in deepening the social dimensions of congregational life, such as through small support or worship groups, potlucks and choirs. This is likely to pay dividends to their congregants in making them happier and also benefit the religious leaders by making their congregants more likely to stay active religious members.”

Specifically, they find that those who attend church sporadically but nonetheless have close friends at church, likely working through religious spouses, are quite high in life satisfaction whereas those who attend church regularly but don’t have church friends are not. “According to the study, 33 percent of people who attend religious services every week and have three to five close friends in their congregation report that they are ‘extremely satisfied’ with their lives” (a 10 on the 1 to 10 question scale). “In comparison, only 19 percent of people who attend religious services weekly, but who have no close friends in their congregation report that they are extremely satisfied. On the other hand, 23 percent of people who attend religious services only several times a year, but who have three to five close friends in their congregation are extremely satisfied with their lives. Finally, 19 percent of people who never attend religious services, and therefore have no friends from congregation, say they are extremely satisfied with their lives.”

Note: Putnam and Lim control for the all the natural demographic correlates that might be causing spurious findings.

The Faith Matters findings apply to the three main Christian traditions (Mainline Protestant, Evangelical Protestant, and Catholic). “We also find similar patterns among Jews and Mormons, even with a much smaller sample size,” said Lim, who noted that there were not enough Muslims or Buddhists in the data set to test the model for those groups.

It’s possible that there are other real-world secular examples of groups where in-group friendships provide the same level of ‘morally-infused” social support: e.g., 12-step programs, or zealous environmental activist networks, or uncorrupted unions, or MADD. Since these findings are relatively new, we haven’t firmly tested to find secular equivalents of these morally-infused networks although it is clear that there is nothing in the US that has anything like the frequency of friends of church, since so many more Americans are in the pews on a Sunday than participating weekly in an environmental group or a 12-step program. The Prime Minister of the UK, David Cameron has made clear to us in conversations, given much lower levels of religiosity in that country, that he is actively interested in finding out if there are secular takeaways from these life satisfaction findings that could be applied in the UK without exhorting more Brits to attend and make friends at church; Cameron’s interest is also sparked by his recent decision to actively measure life satisfaction in the UK as a key indicator of how well government is doing.

We’ll also be doing some further testing in additional surveying we are doing to try to understand more about what makes “close friends at church” so powerful. We welcome your thoughts…

CNN notes: “it is worth examining in the future why this study did not find the same link between happiness and spirituality that others did, the authors say. This may have to do with how different aspects of religion are measured. For example, those who reported that they ‘feel God’s love’ seemed to have more life satisfaction than those who did not, but this did not apply for similar questions about belief in God. Also, it is impossible to draw conclusions about whether ‘feeling God’s love’ causes happiness or vice versa. Could other networks of people have the same effect on happiness? The authors say that if this is possible, it’s hard to think of a non-religious context with a similar strength of identity, intensity of participation in ritual, and great scale and scope of the people in it.”

Cite: “Religion, Social Networks, and Life Satisfaction,” American Sociological Review, 75(6), December 2010.

Beyond CNN, see news stories in USA Today,  National Post, Discovery, Live Science, Science News, TIMES of India, Montreal Gazette, and Daily Mail.

NYC Street-art trying to build social capital

This is a social capital friendly street art that is appearing around New York City.  I’m interested in learning more about whether it is working.  The artistic effort is called “Living Exercises”; not sure who the artist is.

One assumes there is a lot of self-selection going on here — the misanthropes are unlikely to sign up, but maybe this a useful social capital nudge for those of us interested in making new acquaintances.

[hat-tip to “How to Make Friends in Brooklyn“]

The Friendship Paradox: using social networks to predict spread of epidemics

Nick Christakis and James Fowler (whose research we’ve previously highlighted) is back with research that shows how one can easily use “sensors” in a network to track and get early warning regarding the spread of epidemics.

They took advantage of the “friendship paradox” to do so.  In any real-life network, our friends are more popular than we are.  [This is true mathematically in any group with some loners and some social butterflies.  If you poll members in the group about their friendships, far more of those friends who are reported are going to be the social butterflies.  If far more people reported friendships with the loners, they wouldn’t be loners.  See discussion here.]

Thus by asking random people in a network, in this case Harvard students, about their friends, researchers know that their friends are more centrally located in these networks.    Then one can track behavior among the random group and their friends, in this case the spread of H1N1 flu (swine flu) among 744 Harvard students in 2009.

Those more central in these networks (the “friend” group) got the flu a full 16-47 days earlier than the random group.  Thus, for public authorities, monitoring such a “friend” group could give one early indication of a spreading epidemic; they could serve as “canaries in the coal mine”.  If the process of spreading was person-to-person rather than being exposed to some impersonal information (via a website or a broadcast), one could also track the difference between a random group and a friend group to predict other more positive epidemics, like the spread of information, or the diffusion of a product, or a social norm.

We write in general on this blog about the positive benefits of social ties (social capital), but Fowler and Christakis’ study also shows you that having friends and being centrally located has its costs: in this case getting the flu faster.  [In some ways, this is analogous to Gladwell’s discussion in the Tipping Point of how Mavens, Connectors and Salesmen may be disproportionately influential in the spread of ideas through networks, although Fowler and Christakis are far more mathematical in identifying who these central folks are.]

The “friends group manifested the flu roughly two weeks prior to the random group using one method of detection, and a full 46 days prior to the epidemic peak using another method.

‘We think this may have significant implications for public health,’ said Christakis. ‘Public health officials often track epidemics by following random samples of people or monitoring people after they get sick. But that approach only provides a snapshot of what’s currently happening. By simply asking members of the random group to name friends, and then tracking and comparing both groups, we can predict epidemics before they strike the population at large. This would allow an earlier, more vigorous, and more effective response.’

‘If you want a crystal ball for finding out which parts of the country are going to get the flu first, then this may be the most effective method we have now,’ said Fowler. ‘Currently used methods are based on statistics that lag the real world – or, at best, are contemporaneous with it. We show a way you can get ahead of an epidemic of flu, or potentially anything else that spreads in networks.’

Christakis also notes that if you provided a random 30% in a population with immunity to a flu, you don’t protect the greater public, but if you took a random 30% of the population, asked them to name their friends, and then provided immunization to their friends, in a typical network the “friend” immunization strategy would achieve as high immunity protection for the entire network as giving 96% of the population immunity shots, but at less than 1/3 the cost.

The following video shows how the nodes that light up first (markers for getting the flu) are more central and far less likely to be at the periphery of the social network.  The red dots are people getting the flu; the yellow dots are friends of people with the flu and the size of the dot is proportional to how many of their friends have the flu.

Good summary of this research and its implications here: Nick Christakis TED talk (June 2010) – How social networks predict spread of flu.  Nick also discusses some of the implications of computational social science, which we’ve previously discussed here under the heading of digital traces.  Nick discusses how one could use data gathered from these networks (either passively or actively) to do things like predict recessions from patterns of fuel consumption by truckers, to communicate with drivers of a road of impending traffic jams ahead of them (by monitoring from cell phone users on the road ahead of them how rapidly they are changing cell phone towers) to asking those central in a mobile cellphone network (easily mapable today) to text their daily temperature (to monitor for impending flu epidemics).  Obviously these raise issues of privacy, which Nick does not discuss.

News release of study

Academic article in PLoS ONE

James Fowler on The Colbert Report discussing the book by Fowler and Christakis called Connected.

Nick Christakis presenting a talk at TED — The Hidden Influence of Social Networks. (February 2010).  In the talk he notes that while almost half of the variation in our number of friends is genetically-based (46%), that another equally large portion (47%) of whether your friends know each other is a function of whether your friends are the type that introduce (“knit”) their friends together or keep them apart (what they call “transitivity”).  About a third of whether you are in the center of social networks or not is genetically inherited.  Christakis believes that these social networks are critically important to transmitting ideas, and kindness, and information and goodness; and if society realized how valuable these networks were, we’d focus far more of our time, energy and resources into helping these networks to flourish.