Loneliness in our Human Code

Among social determinants of health, loneliness can hugely impact a person’s mental state, physical health, and overall wellbeing. In this brief, we explore how social determinants of health, with a focus on loneliness, affect health over the course of a lifespan, taking into consideration the unique circumstances and needs at each stage of life.

Social Isolation Costs Us

8 years

of life lost, or the equivalent of smoking 15 cigarettes a day1


dollars in additional federal
spending, every year2

When We Feel Excluded,
We Lose Our Fight Against Disease.

It Increases Our Risk for3,4

heart disease
type-2 diabetes
blood pressure
high blood pressure
metastatic cancer

It Impacts Our Body Function4,5,6,7

blood vessel
narrowing blood vessels to preserve body heat
elevating levels of the stress hormone cortisol
reducing antibody protection
decreased cognition
decreasing cognitive function

It's Not Just a Feeling.

is a Co-morbidity

We feel lonely when our current number of social relations (and the quality of those) do not match what we desire8,18. This feeling can lead to a loss of our sense of belongingness, satisfaction with life, and is associated with the onset of co-occuring physical and mental illnesses.

Manifests as Physical Pain

A broken heart exhibits similar physical pain levels as a broken limb because our nervous system processes social rejection in the same area of the brain as physical pain14,15. Evolution has wired socialization into the brain’s automatic reflexes on account of human contact dramatically increasing our chances of survival15.

Is a dysfunction of the brain

The default for the human brain is to assess and respond to our social context and stimuli, otherwise known as our “default network"11. When we feel socially fulfilled, there is a boost in our brain’s reward center (activating dopamine and oxytocin) along with healthy function in the parts of our brain that process social exclusion11,12,13.

Can affect Gene Expression

Studies have found that there may be genomic and hereditary indicators for loneliness, including a study of older people that found 209 abnormally expressed genes in their lonely group6,9,10.
 In the lonely people, genes in charge of activating inflammation were over-expressed while those regulating antiviral and antibody mechanisms w
ere under-expressed6.

The causes and consequences are
unique to every person

Take a look at how social connection varies
Across our lifespan

Resilience in Our Human Code

While these are statistically relevant, humans have the ability to survive and surpass their circumstances to live full and healthy lives. Loneliness, and other social, circumstantial, and behavioral determinants have as much impact on your health as your biology or genetics. If you or someone you know is feeling lonely, check out resources in your neighborhood or reach out to talk to someone. Sometimes a little bit of human contact can go a long way towards living a healthier life.

Take Steps Now34


Vanessa Li, University of Washington

Vanessa specializes in health systems and public health modeling, with an emphasis in substance abuse and disease prevention research. She graduated from the University of Southern California with a B.S. in Public Policy and a double minor in Business Economics and Global Health. Vanessa is working towards a graduate degree in biostatistics at the University of Washington.

Jennifer Patel, GoInvo

Jennifer is a designer-developer hybrid specializing in user interface design and front-end development. She creates beautiful designs using big and small data, often for health and enterprise services. Jennifer joined Invo in 2011 and is a graduate of the Rochester Institute of Technology.


Juhan Sonin, GoInvo, MIT

Juhan specialized in software design and system engineering. He operates, and is the director of, GoInvo. He has worked at Apple, National Center for Supercomputing Applications, Massachusetts Institute of Technology (MIT), and MITRE. Juhan co-founded Invo Boston in 2009 and is a graduate of the University of Illinois at Urbana-Champaign. He currently lectures at MIT.

Parsuree Vatanasirisuk, GoInvo

Parsuree is a user experience designer and illustrator with background in industrial design. She makes the complex beautiful and approachable through illustration and information design. Parsuree joined Invo in 2018, and has a BA in Industrial Design from Chulalongkorn University and is a MFA candidate of the Rochester Institute of Technology (RIT).


  1. Achor, S.; Kellerman, G.R.; Reece, A.; Robichaux, A. (2018). America's Loneliest Workers, According to Research. Harvard Business Review. Retrieved July 31, 2018: https://hbr.org/2018/03/americas-loneliest-workers-according-to-research
  2. Bhattacharya J.; Farid, M.; Flowers, L.; et al. (2017) Medicare Spends More on Socially Isolated Older Adults. AARP. Retrieved June 31, 2018: https://www.aarp.org/content/dam/aarp/ppi/2017/10/medicare-spends-more-on-socially-isolated-older-adults.pdf
  3. Holt-Lunstad, J.; Smith, T.B.; Baker, M; et al. (2015) Loneliness and Social Isolation as Risk Factors for Mortality A Meta-Analytics Review. Perspecitves on Psychological Science. Retrieved August 2, 2018: https://journals.sagepub.com/doi/full/10.1177/1745691614568352
  4. Known risk factors largely explain links between loneliness and first time heart disease / stroke. (2018). British Medical Journal. Retrieved August 2, 2018: https://medicalxpress.com/news/2018-03-factors-largely-links-loneliness-heart.html
  5. Caeioppo, J.; Patrick, W. (2009) Loneliness: Human Nature and the Need for Social Connection. New York: W.W. Norton
  6. American Association for the Advancement of Science. (2007, September 14). Loneliness is in the Genes. Retrieved August 20, 2018: http://www.sciencemag.org/news/2007/09/loneliness-genes
  7. IJzerman, H.; Gallucci, M.; Pouw, W.T.J.L; et al. (2012). Cold-blooded Loneliness: Social exclusions leads to lower skin temperatures. Acta Psychologica. 140. 283-8. 10.1016/j.actpsy.2012.05.002
  8. Campaign to end loneliness impact report: The first three years' achievements. (2013). NCVO. Retrieved August 18, 2018: http://www.scribd.com/document/338317438/Campaign-to-End-Loneliness-impact-report-the-first-three-years-achievements
  9. Neural sensitivity to social rejection is associated with inflammatory responses to social streess. (2010). Proceedings of the National Academy of Science of the United States of America. Retrieved July 14, 2018: https://www.ncbi.nlm.nih.gov/pubmed/20679216
  10. Yirka, B. (2018). Genetic study reveals genes associated with propensity for loneliness and social leanings. Medical Xpress. Retrieved August 12,2018: https://medicalxpress.com/news/2018-07-genetic-reveals-genes-propensity-loneliness.html
  11. Li, W.; Mai, X.; Liu, C. (2014). The default mode network and social understanding of others. What do brain connectivity studies tell us. Frontiers in Human Neuroscience. Retrieved August 10, 2018: https://www.frontiersin.org/articles/10.3389/fnhum.2014.00074/full
  12. Social Science 101: This is Your Brain on Social. (2017) Samuel Centre for Social Connectedness. Retrieved August 1, 2018: https://www.socialconnectedness.org/social-science-101-this-is-your-brain-on-social
  13. The Brain and Social Connectedness: GCBH Recommendations on Social Engageement and Brain Health. (2017). Global Council on Brain Health. Retrieved August 5, 2018: https://www.aarp.org/content/dam/aarp/health/brain_health/2017/02/gcbh-social-engagement-report.pdf
  14. Smith, E. (2013, October 29). Social Connected Makes a Better Brain: Recent trends show that people increasingly value material goods over relationships - but neuroscience and evolution say this goes against out nature. Retrieved August 3, 2018: https://www.theatlantic.com/health/archive/2013/10/social-connection-makes-a-better-brain/280934/
  15. Lieberman, M. (2013). Scoail: Why Our Brains are Wired to Connect. Crown.
  16. Minnesota Department of Health Community and Family Health Division Office of Public Health Practice. (2010). Social Connectedness: Evaluating the Healthy People 2020 Framework: The Minnesota Project. Office of Disease Prevention and Health Promotion, U.S. Department of Health and Human Services. Retrieved August 23, 2018: http://www.health.state.mn.us/divs/opi/resources/docs/1007socialconnectedness_report.pdf
  17. Bakwin, H. (1942). Loneliness in infants. American Journal of Diseases in Children. 63, 30-40
  18. Five Domains of Wellbeing: Social Connectedness (2013). The Fullframe Initiative. Retrieved August 12, 2018: https://fullframeinitiative.org/wp-content/uploads/2011/05/SocialConnectedness_Factsheet.pdf
  19. De Jesus, M.; Puleo, E.; Shelton, R.C.; Emmons, K.M. (2010). Associations between perceived social environment and neighborhood safety: Health implications. Helath & Place, 16, 1007-1013
  20. Franzini, L.; Cuccaro, P.; Schuster, M.; et al. (2009). Influences of physical and social neighborhood environments on children's physical activity and obesity. American Journal of Public Health, 99(2), 271-278
  21. Bruner, C. PhD. (2017) ACE, Place, Rave, and Poverty: Building Hope for Children. Academic Pediatrics. Retrieved July 21, 2018: https://www.sciencedirect.com/science/article/pii/S1876285917303522
  22. Blankenhorn, David. Fatherless America Confronting Our Most Urgent Social Problem. New York: Basic, 1995. Print
  23. CIGNA 2018 U.S. Loneliness Index. (2018). Retrieved August 5, 2018: https://www.multivu.com/players/English/8294451-cigna-us-loneliness-survey/docs/FactSheet_1524071393425-302762795.pdf
  24. Owens, J. (2014). Insufficient Sleep in Adolescents and Young Adults: An Update on Causes and Consequences. From the American Academy of Pediatrics Technical Report. Retrieved August 10, 2018: http://pediatrics.aappublications.org/content/early/2014/08/19/peds.2014-1696
  25. Hirsch, B.J.; Dubois, D.L. (1992). The lation of peer social support and psychological symptomatology during the transition to junior high school: a two-year longitudinal analysis. American Journal of Community Psychology, 20, 333-347
  26. Handebo, S.; Kebede, Y.; Morankar, S. (2017). Does social connectedness influence risky sexual behaviours? Finding from Ethiopian youths. International Journal of Adolescence and Youth. Retrieved August 9, 2018: https://www.tandfonline.com/doi/full/10.1080/02673843.2017.1306448
  27. Makela, K.; Mutonen, H. (1996). The reward structure of drinking among young and older male drinkers. Contemp. Drug Probl. 23: 479-492
  28. Umberson, D.; Montez, J.K. (2010). Social Relationships and Health: A Flashpoint for Health Policy. Journal of Health and Social Behavior, 51 (suppl), S54-S66: http://doi.org/10.1177/0022146510383501
  29. Loneliness is bad for the heart. (2018). European Society of Cardiology. Retrieved August 21, 2018
  30. The Profound power of loneliness. Depression, dementia and even some useful effects: Research examines how loneliness affects the social human brain. (2016). Retrieved August 7, 2018: https://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=137534
  31. Hirsch, M. (2018). How can the death of a loved one affect me? Retrieved August 21, 2018: https://www.sharecare.com/health/grief-emotional-health/how-death-loved-affect-me
  32. Loneliness in Old Age. (nd) Retrieved August 31, 2018: https://www.extracare.org.uk/research/loneliness/
  33. Coile, C.C.; Levine, P.B. (2011). Recessions, Social Security, and Living Arrangements of the Elderly. Retrieved August 21, 2018: http://projects.nber.org/projects_backend/rrc/papers/orrc11-12
  34. Healthline. How to Deal with Loneliness in Today's World: Your Options for Support. Retrieved Nov 8, 2018: https://www.healthline.com/health/how-to-deal-with-loneliness#resources