References & Sources
Every claim on this site is grounded in peer-reviewed research, government data, or authoritative sources. Here is a complete list of the research and data that informs Waterfall's methodology, statistics, and product design.
01Storytelling & Oral Tradition
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Smith, D., et al. (2017). Cooperation and the evolution of hunter-gatherer storytelling. Nature Communications, 8(1), 1853.
https://doi.org/10.1038/s41467-017-02036-8 - •
Wiessner, P. W. (2014). Embers of society: Firelight talk among the Ju/'hoansi Bushmen. Proceedings of the National Academy of Sciences, 111(39), 14027-14035.
https://doi.org/10.1073/pnas.1404212111 - •
Sugiyama, M. S. (2001). Food, foragers, and folklore: The role of narrative in human subsistence. Evolution and Human Behavior, 22(4), 221-240.
https://doi.org/10.1016/S1090-5138(01)00063-0
02Neuroscience of Storytelling
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Zak, P. J. (2015). Why inspiring stories make us react: The neuroscience of narrative. Cerebrum: The Dana Forum on Brain Science, 2.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4445577/ - •
Stephens, G. J., Silbert, L. J., & Hasson, U. (2010). Speaker-listener neural coupling underlies successful communication. Proceedings of the National Academy of Sciences, 107(32), 14425-14430.
https://doi.org/10.1073/pnas.1008662107 - •
Speer, N. K., Reynolds, J. R., Swallow, K. M., & Zacks, J. M. (2009). Reading stories activates neural representations of visual and motor experiences. Psychological Science, 20(8), 989-999.
https://doi.org/10.1111/j.1467-9280.2009.02340.x
03Memory, Recall & Narrative
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Bower, G. H., & Clark, M. C. (1969). Narrative stories as mediators for serial learning. Psychonomic Science, 14(4), 181-182.
https://doi.org/10.3758/BF03342831 - •
Mar, R. A., et al. (2021). Stories as a source of knowledge: A meta-analysis of narrative processing. Psychonomic Bulletin & Review, 28, 1503-1527.
https://doi.org/10.3758/s13423-021-01889-x - •
Mar, R. A., & Oatley, K. (2008). The function of fiction is the abstraction and simulation of social experience. Perspectives on Psychological Science, 3(3), 173-192.
https://doi.org/10.1111/j.1745-6924.2008.00073.x
04Question Methodology & Cognitive Science
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Tulving, E., & Thomson, D. M. (1973). Encoding specificity and retrieval processes in episodic memory. Psychological Review, 80(5), 352-373.
https://doi.org/10.1037/h0020071 - •
Grossmann, I., & Kross, E. (2014). Exploring Solomon's Paradox: Self-distancing eliminates the self-other asymmetry in wise reasoning about close relationships in younger and older adults. Psychological Science, 25(8), 1571-1580.
https://doi.org/10.1177/0956797614535400 - •
Trope, Y., & Liberman, N. (2010). Construal-level theory of psychological distance. Psychological Review, 117(2), 440-463.
https://doi.org/10.1037/a0018963 - •
Jourard, S. M. (1971). The Transparent Self. Van Nostrand Reinhold. See also: Pennebaker, J. W. (1997). Writing about emotional experiences as a therapeutic process. Psychological Science, 8(3), 162-166.
https://doi.org/10.1037/e413792005-265 - •
Buckner, R. L., Andrews-Hanna, J. R., & Schacter, D. L. (2008). The brain's default network: Anatomy, function, and relevance to disease. Annals of the New York Academy of Sciences, 1124(1), 1-38.
https://doi.org/10.1196/annals.1440.011 - •
Barsalou, L. W. (2008). Grounded cognition. Annual Review of Psychology, 59, 617-645.
https://doi.org/10.1146/annurev.psych.59.103006.093639 - •
Pressley, M., et al. (1987). Elaborative interrogation facilitates acquisition of confusing facts. Journal of Educational Psychology, 79(3), 268. See also: Dunlosky, J., et al. (2013). Improving students' learning with effective learning techniques. Psychological Science in the Public Interest, 14(1), 4-58.
https://doi.org/10.1177/1529100612453266
05Seniors, Reminiscence & Therapeutic Benefits
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Bohlmeijer, E., Smit, F., & Cuijpers, P. (2003). Effects of reminiscence and life review on late-life depression: A meta-analysis. International Journal of Geriatric Psychiatry, 18(12), 1088-1094.
https://doi.org/10.1002/gps.1062 - •
Huang, H. C., et al. (2015). Reminiscence therapy improves cognitive functions and reduces depressive symptoms in elderly people with dementia: A meta-analysis of randomized controlled trials. Journal of the American Medical Directors Association, 16(12), 1087-1094.
https://doi.org/10.1016/j.jamda.2015.07.010 - •
Birren, J. E., & Cochran, K. N. (2001). Telling the Stories of Life Through Guided Autobiography Groups. Johns Hopkins University Press.
https://www.press.jhu.edu/books/title/1768/telling-stories-life - •
Butler, R. N. (1963). The life review: An interpretation of reminiscence in the aged. Psychiatry, 26(1), 65-76. Foundational paper on life review therapy.
https://doi.org/10.1080/00332747.1963.11023339
06Population & Demographic Data
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United Nations, Department of Economic and Social Affairs (2022). World Population Prospects 2022. Population Division.
https://population.un.org/wpp/ - •
United Nations (2023). World Population Ageing 2023: Highlights.
https://www.un.org/development/desa/pd/sites/www.un.org.development.desa.pd/files/undesa_pd_2023_wpa-highlights.pdf - •
Centers for Disease Control and Prevention (2023). National Vital Statistics Reports — Deaths and Mortality.
https://www.cdc.gov/nchs/fastats/deaths.htm - •
World Health Organization (2024). Global Health Estimates — Mortality and Global Health Estimates.
https://www.who.int/data/gho/data/themes/mortality-and-global-health-estimates
07Mental Health & Loneliness
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U.S. Surgeon General (2023). Our Epidemic of Loneliness and Isolation: The U.S. Surgeon General's Advisory on the Healing Effects of Social Connection and Community.
https://www.hhs.gov/sites/default/files/surgeon-general-social-connection-advisory.pdf - •
Centers for Disease Control and Prevention (2023). Household Pulse Survey — Anxiety and Depression.
https://www.cdc.gov/nchs/covid19/pulse/mental-health.htm
08Digital Divide & Online Content
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Pew Research Center (2024). Internet/Broadband Fact Sheet — Internet and Technology Use by Age.
https://www.pewresearch.org/internet/fact-sheet/internet-broadband/ - •
Pew Research Center (2024). Social Media Fact Sheet — Social Media Use by Age.
https://www.pewresearch.org/internet/fact-sheet/social-media/
09AI Training Data & Limitations
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Bender, E. M., Gebru, T., McMillan-Major, A., & Shmitchell, S. (2021). On the Dangers of Stochastic Parrots: Can Language Models Be Too Big? Proceedings of the 2021 ACM Conference on Fairness, Accountability, and Transparency (FAccT), 610-623.
https://doi.org/10.1145/3442188.3445922
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