References for "Infectious health behaviors"
Cacippo JT, et al. "Alone in the Crowd: The Structure and Spread of Loneliness in a Large Social Network," Journal of Personality and Social Psychology (in press).
Christakis NA, et al. "The Collective Dynamics of Smoking in a Large Social Network," New England Journal of Medicine (May 22, 2008): Vol. 358, No. 21, pp. 2249–58. www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18499567