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. Citations marked [verify] are ones whose exact author list, year, or venue should be confirmed before publication.

Page ranges and title punctuation have been normalized to this manuscript's punctuation standard; exact bibliographic metadata must be checked during that pass. Descriptive notes are editorial 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. Editorial note: examine whether the study supports claims about shared attention, and preserve its task and population limits.
• A systematic review and meta-analysis of interpersonal autonomic-nervous-system synchrony and its association with relationship and performance outcomes. Physiology & Behavior (2021). [verify authors] Synchrony is greater between friends than strangers in positive conditions; effects are real but heterogeneous. Editorial note: verify all subgroup claims.
• Palumbo, R. V., et al. (2017). Interpersonal autonomic physiology: A systematic review of the literature. Personality and Social Psychology Review. [verify] Foundational review of physiological "linkage" across relationships.
• "Seeing each other matters: Visual contact enhances heart-rate-variability synchrony between interaction partners" (2026 preprint). [verify title, authors, venue, and preprint status] Mutual visual contact strengthens HRV synchrony. Editorial note: do not treat a preprint as settled evidence.
• Cardiac synchrony in parent-infant dyads during shared reading or play. SHER project, bioRxiv preprint. [verify title, authors, and version] Early relational synchrony and its enhancement through shared attention. Editorial note: determine what shared attention adds beyond 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. Editorial note: distinguish measured findings from theory-specific interpretation.
• Shaffer, F., & Ginsberg, J. P. (2017). An overview of heart rate variability metrics and norms. Frontiers in Public Health. [verify volume, article number, and exact scope] Summary of HRV measures and the major interpreting theories.

• 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. [verify volume and pages]
• Greenwood, B. M., & Garfinkel, S. N. (2024). Interoceptive mechanisms and emotional processing. Annual Review of Psychology. [verify title, authors, year, and venue]
• Damasio, A. R. (1994). Descartes' Error: Emotion, Reason, and the Human Brain. The somatic-marker hypothesis: bodily signals guide decision-making. Editorial note: do not treat it as direct validation of 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). Editorial note: verify the manuscript's summary of implicated regions and avoid translating neural activation into a universal human need without further support.
• Reis, H. T., Lemay, E. P., & Finkenauer, C. (2017). Toward understanding understanding: The importance of feeling understood in relationships. Social and Personality Psychology Compass. [verify volume, issue, and article details]

• 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. Editorial note: supports design principles for 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. Editorial note: verify how directly they challenge the specific claims made in the chapter.

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

• Research associated with Rollin McCraty and the HeartMath Institute on cardiac coherence and interpersonal synchrony. [verify exact primary studies, methods, independent replication, and appropriate terminology] Editorial note: this work has been used to support strong claims about heart rhythms during genuine presence. No such claim should stand until the sources and limits are established.
• A Scientific Reports article from 2025 described as showing concentration-dependent cardiovascular effects of oxytocin. [verify authors, exact title, design, population, and what was measured] Editorial note: 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. [verify primary studies, device conditions, accuracy, and real-world readiness]
• Research attributed to groups including the Chinese Academy of Sciences on pulse-wave biomarkers correlated with stress, cognitive load, and emotional state. [verify investigators, exact papers, features, effect sizes, and populations]
• Foundational literature on pulsatile hormone secretion. [identify and cite the specific reviews or primary sources] Editorial note: pulsatile secretion does not by itself make an endocrine state inferable from peripheral cardiovascular data.

The epilogue also depends on Aldo Leopold's "The Land Ethic." [verify composition date, publication history, edition, and exact account of the land community before publication]

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.