[1] Fowler J H, Christakis N A. Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart
[2] Study BMJ 2008; 337 :a2338 doi:10.1136/bmj.a2338
https://www./doi/full/10.1056/nejmsa066082
[3] Holt-Lunstad J, Smith TB, Layton JB (2010) Social Relationships and Mortality Risk: A Meta-analytic Review. PLoS Med 7(7): e1000316. https:///10.1371/journal.pmed.1000316
[4] Yang, Y. C., Boen, C., Gerken, K., Li, T., Schorpp, K., & Harris, K. M. (2016). Social relationships and physiological determinants of longevity across the human life span. Proceedings of the National Academy of Sciences, 113(3), 578-583.
[5] Adler, N. E., & Newman, K. (2002). Socioeconomic disparities in health: pathways and policies. Health affairs, 21(2), 60-76.
[6] Taylor, S.E., Klein, L.C., Lewis, B.P., Gruenewald, T.L., Gurung, R.A., & Updegraff, J.A. (2000). Biobehavioral responses to stress in females: tend-and-befriend, not fight-or-flight. Psychological review, 107 3, 411-29 .
[7] Wright, P. H. (1982). Men's friendships, women's friendships and the alleged inferiority of the latter. Sex Roles: A Journal of Research, 8(1), 1–20. https:///10.1007/BF00287670