Knowledge Matters™

Sometime ago I posted some commentary about this study by Doctor Nicholas Christakis and Doctor James Fowler, who used network analysis to aid understanding of obesity. Their results were published in the New England Journal of Medicine. It was an interesting study because it looked at 12,067 subjects over a 32-year period. Some of the results were truly frightening - if you have a close friend who is obese the chance of you becoming obese increases by 57%! But I digress. This time, Doctors Christakis and Fowler have used social network analysis techniques to aid understanding of the collective dynamics of smoking.

Again it is a very interesting study. Given the population is 12,067 subjects over a 32-year period it appears to be the same group used in the obesity study. A couple of findings were really interesting.

• First, smoker-clusters extend to three degrees of separation.
• Second, the size of the smoker-clusters remained the same across time, suggesting that whole groups of people quit at the same time.
• Third, smokers are found in the periphery of the total social network, suggesting smokers are increasingly being marginalized by their peers, family and co-workers.

These findings analysed together suggest the decision to stop smoking is not solely a personal one. Indeed the decision to continue smoking meant the individual became increasingly peripheral in the network, and perhaps even marginalized. It appears smoking is not just bad for your personal health; it's also bad for your social health. That said I am cautious in drawing the marginalisation conclusion because equally this person could become a Tertius Iungens - a person on the periphery of a network who acts as a broker between networks.

Obviously there are social factors at play and it is not easy to attribute simple cause and effect. Then again this is a very sound study and deserves not to be discounted outright. It's also a good example of a lateral use of network analysis. For those of you who are interested in the uses of network analysis - I recommend you read the study . Once again personal choice, responsibility, the ability to say no, and your social networks matter!

Regards, Graham