Appendix: Evidence Map and Verification Queue

A note on this appendix. What follows is a working, deliberately incomplete list of the research on which the empirical claims of this volume rest. We offer it in the spirit named throughout the book: not as proof, but as the ground a doubter is entitled to stand on before deciding what to believe. Three honesties belong at the top. First, this list is partial: it reflects what we have found, not the whole of what exists, and we expect readers to extend and correct it. Second, these studies establish correlates and mechanisms (that presence has measurable physiological signatures, that the body's signals track regulation and emotion, that being understood and coordinating well are real and measurable), not that the full Currency of Presence has been built or validated. The validation studies this book calls for are precisely what is still missing; that is the point. Third, we invite adversarial reading. Put these citations in front of a capable AI and ask it to check our claims against the literature, to find where we have overreached, to surface what we have left out. A thesis that cannot survive that scrutiny does not deserve belief.

Bibliographic details vary in completeness; entries without full metadata should be treated as research leads rather than settled citations. Descriptive notes are summaries, not quotations from the cited works.

• Boukarras, S., et al. (2025). Interpersonal physiological synchrony during dyadic joint action is increased by task novelty and reduced by social anxiety. Psychophysiology. Cardiac synchrony rises when a dyad attends to a shared challenge; social anxiety reduces it. Its relevance is limited by the study's task and population.
• A systematic review and meta-analysis of interpersonal autonomic-nervous-system synchrony and its association with relationship and performance outcomes. Physiology & Behavior (2021). Synchrony is greater between friends than strangers in positive conditions; effects are real but heterogeneous. The author list and subgroup claims remain incomplete here.
• Palumbo, R. V., et al. (2017). Interpersonal autonomic physiology: A systematic review of the literature. Personality and Social Psychology Review. Foundational review of physiological "linkage" across relationships; the citation should not be treated as evidence for claims beyond the review's scope.
• "Seeing each other matters: Visual contact enhances heart-rate-variability synchrony between interaction partners" (2026 preprint). Mutual visual contact strengthens HRV synchrony. As a preprint with incomplete bibliographic details, it is not settled evidence.
• Cardiac synchrony in parent-infant dyads during shared reading or play. SHER project, bioRxiv preprint. Early relational synchrony and its enhancement through shared attention. The evidence does not yet isolate shared attention from common task and respiration.

• Thayer, J. F., & Lane, R. D. (2000). A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders, 61, 201 to 216.
• Thayer, J. F., Hansen, A. L., Saus-Rose, E., & Johnsen, B. H. (2009). Heart rate variability, prefrontal neural function, and cognitive performance. Annals of Behavioral Medicine, 37, 141 to 153.
• Porges, S. W. (2007). The polyvagal perspective. Biological Psychology, 74, 116 to 143. Measured findings and theory-specific interpretation remain distinct.
• Shaffer, F., & Ginsberg, J. P. (2017). An overview of heart rate variability metrics and norms. Frontiers in Public Health. Summary of HRV measures and the major interpreting theories; the exact bibliographic scope remains incomplete here.

• Garfinkel, S. N., Seth, A. K., Barrett, A. B., Suzuki, K., & Critchley, H. D. (2015). Knowing your own heart: Distinguishing interoceptive accuracy from interoceptive awareness. Biological Psychology, 104, 65 to 74.
• Garfinkel, S. N., Minati, L., Gray, M. A., Seth, A. K., Dolan, R. J., & Critchley, H. D. (2014). Fear from the heart: Sensitivity to fear stimuli depends on individual heartbeats. Journal of Neuroscience, 34(19), 6573 to 6582.
• Critchley, H. D., & Garfinkel, S. N. (2017). Interoception and emotion. Current Opinion in Psychology. Volume and page details remain incomplete here.
• Greenwood, B. M., & Garfinkel, S. N. (2024). Interoceptive mechanisms and emotional processing. Annual Review of Psychology. The exact title, authorship, year, and venue remain uncertain.
• Damasio, A. R. (1994). Descartes' Error: Emotion, Reason, and the Human Brain. The somatic-marker hypothesis: bodily signals guide decision-making. This does not directly validate Providence.

• Morelli, S. A., Torre, J. B., & Eisenberger, N. I. (2014). The neural bases of feeling understood and not understood. Social Cognitive and Affective Neuroscience, 9(12), 1890 to 1896. Feeling understood activates reward and social-connection regions (ventral striatum, middle insula). The implicated regions and any translation into a universal human need require caution.
• Reis, H. T., Lemay, E. P., & Finkenauer, C. (2017). Toward understanding understanding: The importance of feeling understood in relationships. Social and Personality Psychology Compass. Volume, issue, and article details remain incomplete here.

• Woolley, A. W., Chabris, C. F., Pentland, A., Hashmi, N., & Malone, T. W. (2010). Evidence for a collective intelligence factor in the performance of human groups. Science, 330(6004), 686 to 688.
• Edmondson, A. C. (1999). Psychological safety and learning behavior in work teams. Administrative Science Quarterly, 44(2), 350 to 383.
• Ostrom, E. (1990). Governing the Commons: The Evolution of Institutions for Collective Action. Cambridge University Press. Its design principles concern governed commons, not biometric governance.
• The dissent, included in good faith: Credé, M., & Howardson, G. (2017). The structure of group task performance: A second look at "collective intelligence." Journal of Applied Psychology, 102(10), 1483 to 1492; and Bates, T. C., & Gupta, S. (2017). Smart groups of smart people: Evidence for IQ as the origin of collective intelligence. Intelligence, 60, 46 to 56. Both argue the collective-intelligence factor is weaker than first reported and largely tracks individual ability. We list them because a thesis that hides its strongest critics has not earned trust. How directly they challenge the chapter's specific claims remains unsettled.

• Reduced heart-rate variability in adults with autism spectrum disorder. Autism Research (2019). Lower resting parasympathetic (HF, RMSSD) activity in autistic adults versus neurotypical controls. Authors, exact title, measures, sample, and the limits of comparison remain incomplete here.
• Heart-rate variability in autism spectrum disorder: A meta-analysis (2020). Aggregated evidence of autonomic differences in ASD. Authors, venue, and exact title remain incomplete here.
• Autistic traits moderate relations between cardiac autonomic activity, interoceptive accuracy, and emotion processing (2020). Trait-level differences change how autonomic signals, interoception, and emotion relate. Authors, venue, and exact title remain incomplete here.
• Feasibility of HRV as an outcome measure for emotion-regulation interventions in autism. Scientific Reports (2024). Indicates HRV-based tools may support neurodivergent people, not exclude them. Feasibility does not establish fairness or benefit for a currency system, and the bibliographic details remain incomplete here.

• Research associated with Rollin McCraty and the HeartMath Institute on cardiac coherence and interpersonal synchrony. Exact primary studies, methods, independent replication, and terminology remain unestablished here; strong claims about heart rhythms during genuine presence should not rest on this entry.
• A Scientific Reports article from 2025 described as showing concentration-dependent cardiovascular effects of oxytocin. The authors, design, population, and measured effect remain unidentified, and cardiovascular effects do not establish that bonding can be inferred from an ordinary pulse signal.
• Wearable cortisol sensing using molecularly imprinted polymers, described as validated in work from 2024 and 2025. Primary studies, device conditions, accuracy, and real-world readiness remain unidentified.
• Research attributed to groups including the Chinese Academy of Sciences on pulse-wave biomarkers correlated with stress, cognitive load, and emotional state. Investigators, papers, features, effect sizes, and populations remain unidentified.
• Foundational literature on pulsatile hormone secretion. Specific sources remain unidentified, and pulsatile secretion does not by itself make endocrine state inferable from peripheral cardiovascular data.

The epilogue also draws on Aldo Leopold's "The Land Ethic." Its composition date, publication history, edition, and exact account of the land community are not established here.

The open research need is now precise. Providence requires studies that test the integrated mechanism across varied populations, compare model inference with participant and observer accounts, measure harm as well as usefulness, preserve the right to refuse, and publish null or adverse results. Until then, the Four Streams remain a research program rather than a validated mint.

This appendix is itself a nest: woven from what we could gather, left open on purpose. If you know of work that belongs here (confirming, complicating, or refuting what this volume claims), it belongs to the next hands to add it.