The New York Times has a brilliant article on how human traits and behaviours, including everything from happiness to obesity, can spread through social networks.
It discusses the findings of the Framington Heart Study. Originally designed to be a study of heart disease in a small American town, it recorded each participant’s family and friends in case the researchers lost touch with anyone.
This data allowed sociologists Nicholas Christakis and James Fowler to reconstruct the social networks of the participants and test how family, work and friendship connections affected the spread of things like happiness, obesity and smoking. Their data suggests that even quite nebulous experiences like happiness ‘travel’ through our web of relationships, as we discussed when they released this study last year.
Coincidentally Wired has also just published an article on the same topic which has some of the stunning network maps from the study, but I really recommend reading the New York Times in full as it is not solely on this one study, it also serves as a nuanced discussion about the usefulness and limitations of social network analysis.
Not least is the difficulty of judging to what extent these effects ‘travel’ through relationships or how much the ‘birds of a feather’ effect means similar people just flock together.
You need to understand social network analysis because it is becoming one of the most powerful method to understand human behaviour. As we’ve discussed before, the fact that digital communications technology is so common means that we’re constantly creating data trails that can reveal surprising amounts of intimate information with relatively simple methods.
For example, the BPS Research Digest just covered a study that could infer about 95% of friendships just from looking at location data from mobile phones – something that is one of the most basic information trails in the rich data stream automatically produced by social media.
This approach to understanding human networks is also likely to be increasingly important for human science. The last few decades have seen a massive increase in understanding on how genetics influences our minds and behaviour and social network analysis will see us increasingly linking individual discoveries from biology and cognitive science to the role of our relationships in our lives.
Link to NYT piece ‘Is Happiness Catching?’
Link to Wired piece ‘The Buddy System’.
Link to Mind Hacks on ‘The distant sound of well-armed sociologists’.
Mind Hacks 
Hi Vaughan,
This is indeed an interesting article. I found one paragraph a tad dubious, when the author talked about the spread of ‘happiness’ –
‘the spread of good or bad feelings, they say, might be driven partly by ‚Äúmirror neurons‚Äù in the brain that automatically mimic what we see in the faces of those around us ‚Äî which is why looking at photographs of smiling people can itself often lift your mood.’
What do you say to this? Is there any indication that the brain does this? For one thing, I thought mirror neurons were discovered in macaques, not humans (unless that’s a recent development). It seems like a bit of a jump to me.