ArendtHannah Arendt, a 20th-century political philosopher who tied widespread loneliness to the rise of totalitarian politics., H. (1951). The Origins of Totalitarianism.
Harcourt, Brace & Co.. Open source ↗
BlanchflowerDavid Blanchflower, an economist who found that well-being by age has flipped, with the young now the least content., D. G., Bryson, A. & Xu, X. (2025). The declining mental health of the young and the global disappearance of the unhappiness hump-shape in age.
PLOS ONE, 20. Open source ↗
Bureau of Labor Statistics (2024). American Time Use Survey — Time Spent in Social Activities.
Synthesized with Sarah Cowan & Daniel A. Cox analyses (Georgetown / Survey Center on American Life). Open source ↗
Bureau of Labor Statistics (2024). American Time Use Survey — 2024 Results (Table 1; socializing & communicating).
BLS news release USDL-25-1162. Open source ↗
CacioppoJohn Cacioppo, the psychologist who built much of the modern science of loneliness., J. T. & Hawkley, L. C. (2009). Perceived Social Isolation and Cognition.
Trends in Cognitive Sciences, 13(10), 447–454. Open source ↗
CacioppoJohn Cacioppo, the psychologist who built much of the modern science of loneliness., J. T., Fowler, J. H. & Christakis, N. A. (2009). Alone in the Crowd: The Structure and Spread of Loneliness in a Large Social Network.
Journal of Personality and Social Psychology, 97(6), 977–991. Open source ↗
Centers for Disease Control and Prevention (2024). Youth Risk Behavior Survey — High school students reporting persistent feelings of sadness or hopelessness in the past year, 2005–2023.
CDC YRBS Data Summary & Trends Report (biennial). Open source ↗
Cohen-Cole, E. & Fletcher, J. M. (2008). Detecting implausible social network effects in acne, height, and headaches: longitudinal analysis.
BMJ, 337, a2533. Open source ↗
Cox, D. A. (Survey Center on American Life) (2021). The State of American Friendship: Change, Challenges, and Loss.
Survey Center on American Life — May 2021 American Perspectives Survey. Open source ↗
Crowe, C. L., Domingue, B. W., Graf, G. H., et al. (2021). Associations of Loneliness and Social Isolation with Health Span and Life Span in the U.S. Health and Retirement Study.
Journals of Gerontology Series A, 76(11), 1997–2006. Open source ↗
Curtin, S. C., Garnett, M. F. & Hedegaard, H. (2024). Changes in Suicide Rates in the United States, 2002–2023 — Age-Adjusted Death Rates per 100,000.
CDC NCHS Data Briefs No. 509 (2024) and No. 541 (2025). Open source ↗
Evans, A. (Stanford University / King's College London) (2025). The Great Gender Divergence — young men and women moving into separate social worlds.
The Great Gender Divergence project; cf. Burn-Murdoch, Financial Times (26 Jan 2024). Open source ↗
Fry, R. & Parker, K. (2025). Rising Share of U.S. Adults Are Living Without a Spouse or Partner (2021) and Share of U.S. Adults Living Without a Romantic Partner Has Ticked Down in Recent Years (2025).
Pew Research Center Social & Demographic Trends — analyses of U.S. Census Bureau decennial census and American Community Survey 1-year estimates. Open source ↗
Greenland, S., Pearl, J. & Robins, J. M. (1999). Causal Diagrams for Epidemiologic Research.
Epidemiology, 10(1), 37–48. Open source ↗
Holt-LunstadJulianne Holt-Lunstad, a researcher whose large reviews showed that weak social ties raise the risk of dying early., J., Smith, T. B. & Layton, J. B. (2010). Social Relationships and Mortality Risk: A Meta-analytic Review.
PLOS Medicine, 7(7), e1000316. Open source ↗
Holt-LunstadJulianne Holt-Lunstad, a researcher whose large reviews showed that weak social ties raise the risk of dying early., J., Smith, T. B., Baker, M., Harris, T. & Stephenson, D. (2015). Loneliness and Social Isolation as Risk Factors for Mortality: A Meta-Analytic Review.
Perspectives on Psychological Science, 10(2), 227–237. Open source ↗
Hughes, M. E., Waite, L. J., Hawkley, L. C. & CacioppoJohn Cacioppo, the psychologist who built much of the modern science of loneliness., J. T. (2004). A Short Scale for Measuring Loneliness in Large Surveys.
Research on Aging, 26(6), 655–672 — UCLA 3-Item. Open source ↗
Hunt, M. G., Marx, R., Lipson, C. & Young, J. (2018). No More FOMO: Limiting Social Media Decreases Loneliness and Depression.
Journal of Social and Clinical Psychology, 37(10), 751–768. Open source ↗
Kannan, V. D. & Veazie, P. J. (2023). US trends in social isolation, social engagement, and companionship — nationally and by age, sex, race/ethnicity, family income, and work hours, 2003–2020.
SSM — Population Health, 21 (PMC9811250). Open source ↗
KlinenbergEric Klinenberg, the sociologist who named “social infrastructure,” the shared places that hold communities together., E. (2018). Palaces for the People: How Social Infrastructure Can Help Fight Inequality, Polarization, and the Decline of Civic Life.
Crown. Open source ↗
Lyons, R. (2011). The Spread of Evidence-Poor Medicine via Flawed Social-Network Analysis.
Statistics, Politics & Policy, 2(1), Article 2. Open source ↗
National Opinion Research Center (NORC) (2024). 1972–2024 General Social Survey Cumulative File (variable: TRUST).
GSS Data Explorer / SDA Berkeley archive. Open source ↗
PutnamRobert Putnam, the political scientist who charted the fraying of American community in “Bowling Alone.”, R. D. (2000). Bowling Alone: The Collapse and Revival of American Community.
Simon & Schuster. Open source ↗
Schwartz, B. (2004). The Paradox of Choice: Why More Is Less.
Ecco / HarperCollins — choice overload and satisfaction. Open source ↗
Silver, L., Keeter, S., Kramer, S., Lippert, J., et al. (Pew Research Center) (2025). Americans' Trust in One Another (and Why It's Declining): The share answering 'most people can be trusted' fell from 46% in 1972 to 34% in 2018.
Pew Research Center, 8 May 2025. Open source ↗
Steptoe, A., Shankar, A., Demakakos, P. & Wardle, J. (2013). Social isolation, loneliness, and all-cause mortality in older men and women.
PNAS, 110(15), 5797–5801. Open source ↗
The Cigna Group / Morning Consult (2025). The 2025 Loneliness in America Report — generational breakdown showing the youngest adults most lonely and Boomers least.
Cigna Group, Loneliness in America Report (2025 release). Open source ↗
Thompson, D. (2025). The Anti-Social Century.
The Atlantic — February 2025 cover story. Open source ↗
TwengeJean Twenge, a psychologist who studies how each generation differs, including teenagers socializing less., J. M. & Park, H. (2019). The Decline in Adult Activities Among U.S. Adolescents, 1976–2016.
Child Development, 90(2), 638–654 — Monitoring the Future, N ≈ 8.4 million. Open source ↗
U.S. Census Bureau (2024). America's Families and Living Arrangements: 2024.
U.S. Census Bureau Current Population Survey. Open source ↗
U.S. Census Bureau (2024). Historical Households Tables — HH-1 (Households by Type) & HH-4 (Households by Size), 1940–2024.
U.S. Census Bureau, Current Population Survey. Open source ↗
U.S. Surgeon GeneralThe top public-health official in the U.S.; the 2023 advisory called loneliness a health emergency. (Vivek Murthy) (2023). Our Epidemic of Loneliness and Isolation.
U.S. Department of Health & Human Services advisory. Open source ↗
VanderWeele, T. J. (2011). Sensitivity Analysis for Contagion Effects in Social Networks.
Sociological Methods & Research, 40(2), 240–255. Open source ↗
VanderWeele, T. J. & Ding, P. (2017). Sensitivity Analysis in Observational Research: Introducing the E-Value.
Annals of Internal Medicine, 167(4), 268–274. Open source ↗
World Health Organization (2025). From Loneliness to Social Connection: Charting a Path to Healthier Societies.
WHO Commission on Social Connection — flagship report. Open source ↗
World Health Organization (2025). Social connection linked to improved health and reduced risk of early death.
WHO press release, 30 June 2025. Open source ↗