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, and some commentary on this study where they used network analysis to aid the understanding smoking behaviour.  Both studies were published in the New England Journal of Medicine. I also posted some commentary about a study on happiness published in the January 2009 edition of the British Medical Journal, or BMJ for short.  Last year Doctors Christakis and Fowler published a book called Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives.  I'll be doing a book review in the next few days.  In the meantime the video below features Doctor Fowler talking about their work - it's well worth viewing. 

Regards Graham