Tom
e25b2c05d1
Theory revised and narrowed to what the evidence supports; renamed The
Relevance Theory. Project split into two books and six essays, with the
three-tier relevance model promoted to the flagship.
- EVIDENCE.md claims sorted into four tiers, governs what may be claimed
- CRAFT.md lyric/landscape register, governs how it may be said
- PORTFOLIO.md the two-book plus six-essay split, and what was cut
- BOOK_ONE_CHAPTERS.md walk spine on the Stezka Ceskou Kanadou,
beats for all 14 units, argument ledger
- FIELD_BRIEF.md what to capture on the trail
- drafts/ prologue, ch 3, ch 5 (register tests, specifics are placeholders)
- archive/ original theory and outline, unchanged
Cut: the foreign-policy argument, the weight-loss protocol, the diagnostic
scoring, the I/me labels, the seasonal network mapping (demoted to metaphor
in Book Two).
111 lines
11 KiB
Markdown
111 lines
11 KiB
Markdown
# Evidence tiers
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*Every load-bearing claim in this project, sorted by how much weight it can actually carry. This file governs the register each chapter may be written in. If a claim isn't in here, it hasn't been checked yet — don't build on it.*
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The rule: **a chapter can only be written in the voice its evidence tier permits.** Tier A can be stated. Tier B must present the dispute. Tier C must be marked as the author's hypothesis, in the text, not just in a footnote. Tier D is memoir or metaphor and cannot carry an argument.
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---
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## Tier A — Well-supported. State it, cite it, move on.
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**The brain conserves energy by reusing models rather than building them.**
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Predictive processing / free energy principle (Friston; Andy Clark), cognitive miser theory (Fiske & Taylor, 1984), System 1 / System 2 (Kahneman). Convergent from three independent traditions. The claim that heuristics and stereotyping are thrift rather than laziness is defensible as written.
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**DMN and TPN exist, and are broadly anticorrelated.**
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Standard, replicated resting-state neuroimaging. Safe.
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**The salience network exists and is implicated in switching between them.**
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Menon's triple-network model (2011); causal support from dynamic causal modelling and Granger analyses (Sridharan et al. 2008 and replications), with the right anterior insula governing executive-to-default transitions. *Caveat to keep visible:* "switchboard" is a functional simplification. The networks overlap, co-activate, and are not discrete modules. Say this once, early, and you've earned the metaphor for the rest of the book.
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**Nature exposure reduces rumination.**
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Bratman et al. 2015 (PNAS): 90 minutes in a natural setting reduced self-reported rumination *and* subgenual prefrontal cortex activation; 90 minutes in an urban setting did neither. This is the single best-evidenced practical claim in the whole project — it's a controlled comparison with both a self-report and a neural measure, and the urban walk is the right control. Build the nature chapter on this.
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**Chronic stress raises appetite for energy-dense food.**
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Adam & Epel (2007) and the surrounding cortisol-reactivity literature. Acute stress suppresses appetite; *chronic* elevation increases hunger and shifts preference toward sugar and fat. Note the acute/chronic distinction — it's the part popular writing gets wrong.
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**Seasonal variation in brain response to cognitive tasks is real.**
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Meyer et al. 2016 (PNAS): attention-related activity peaked near the summer solstice, working-memory activity near the autumn equinox. **Read this carefully — it supports "the brain varies across the year" and actively fails to support the DMN-winter / TPN-summer mapping.** Cite it honestly or not at all.
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**Segmented sleep in pre-industrial Western Europe.**
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Ekirch's historical documentation is solid *for that time and place*. See Tier B for the overreach.
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---
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## Tier B — Contested. You must present the dispute, in the text.
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These are the ones that will get the book attacked if handled as settled. Handled openly, several of them become more interesting than the tidy version would have been.
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**Biphasic sleep as a universal human pattern — no.**
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Ekirch documents it for pre-industrial Europe. Yetish et al. 2015 studied three equatorial pre-industrial societies without electric light and found no regular extended night waking, concluding the pattern probably post-dates migration into Western Europe. Ekirch has responded that he never claimed universality. **The honest version: segmented sleep is a documented Western European historical pattern, not a human default.** That's still a good chapter — it just becomes a story about cultural variation rather than about recovering our nature.
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**Seasonality of mood — much weaker than folk belief.**
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Traffanstedt, Mehta & LoBello (2016) found no relationship between depression severity and season, latitude, or sunlight exposure in a large US survey sample, and argued the seasonal modifier lacks validity. Young (2017) published a rebuttal. This is genuinely unresolved. **This is the most dangerous single fact for Book Two** and must be met head-on in its opening chapters rather than avoided — the book's argument has to become "seasonal structure is worth designing" rather than "your mood follows the seasons."
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**Dunbar's number.**
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Lindenfors et al. 2021 re-ran the underlying regression with modern methods and got estimates from 16 to 109 with 95% confidence intervals spanning 2–520 — meaning no specific number is derivable. **Use the idea of a bounded social world; never use the figure 150.**
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**Media multitasking impairs attention — small and inconsistent.**
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Ophir et al. 2009 is the famous study; it largely failed to replicate. Wiradhany & Nieuwenstein (2017) ran two replications and a meta-analysis of the subsequent literature, finding an effect in the same direction but much smaller — around d = 0.17 — with a substantial minority of individual results pointing the opposite way. The effect may be real but is nothing like the size popular writing implies. Don't lean on it. *(Check the exact study count against the paper before citing a number in print.)*
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**Digital detox — and this one helps you.**
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Review evidence is poor quality (roughly 96% of studies rated weak, small non-representative samples). Total abstinence has the *weakest* record of any approach; some studies find no change and several find harm during the detox. Social-media-specific breaks do better, and therapy-style interventions that change *how* people use platforms outperform both limiting and abstaining. **This is direct support for the book's central practical claim: retriage beats abstention.** Use it.
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---
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## Tier C — Plausible, untested. Mark as hypothesis, in the text.
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This is where the original contribution lives. Untested is not the same as weak — but it has to be labelled, every time, or the book is overclaiming.
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- **The three-tier relevance model** (day's walk / day's ride / beyond the horizon). Nobody has tested this. It's the best idea in the project and it is entirely yours and entirely unvalidated. Say both things.
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- **Tier collapse as the mechanism of information fatigue** — that distant information carrying local-urgency signals is what exhausts people, rather than volume or reward-hacking.
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- **Salience-network flexibility as the lever**, rather than favouring reflection or focus. The theory's central practical claim.
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- **The actionability gap** — that the specific harm of modern news is caring intensely about things you cannot affect. Currently the most under-developed idea in the project and possibly the most valuable.
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- **Salience environment over step count** — that 5,000 steps somewhere quiet beats 10,000 in a corridor. Bratman gives partial support (setting mattered, distance didn't) but the strong version is untested.
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- **Work-life balance complaints as switching failures rather than time-allocation failures.**
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- **Desk hunger as cognitive load misread as fuel demand.** The cortisol literature (Tier A) supports stress→appetite; your specific interoceptive-suppression mechanism is your own and unverified.
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---
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## Tier D — Speculative or personal. Cut, or flag explicitly as speculation.
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**Cut entirely:**
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- **The foreign-policy claim** (TPN-dominant societies bias toward interventionism). Unfalsifiable, politically loaded, and a single quotation from it discredits everything else in the book. Nothing is lost by removing it.
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- **The DMN-based weight-loss protocol.** A prescriptive four-anchor health regimen resting on an invented mechanism. "Weight regulation follows nervous-system safety, not willpower" is an unsupported clinical claim about a population that includes vulnerable readers. The underlying *observation* — hunger after desk work, none after trekking — survives as a personal essay. The protocol does not.
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- **The diagnostic test's numeric scoring.** Thresholds like "≥12 indicates imbalance" confer clinical precision derived from a single respondent. Keep the twenty questions as reflection prompts with no scoring, no cutoffs, and no diagnostic language.
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- **The "I" / "me" labels for DMN and TPN.** These invert what most readers intuit, add no explanatory power, and create an unnecessary defence burden. Drop them.
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**Demote to explicit metaphor:**
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- **The seasonal DMN/TPN/SN mapping.** No evidence supports the specific assignment, and Meyer 2016 points the other way. It survives — usefully — as a *design metaphor* for structuring a year, which is how Book Two should frame it from page one.
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---
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## The internal contradiction to resolve before drafting
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The current theory treats DMN activity as the thing modern life starves us of, and therefore as good. But:
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- Killingsworth & Gilbert (2010) found mind-wandering — the DMN's signature activity — predicted *lower* momentary happiness, and accounted for more variance in happiness than what people were actually doing.
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- Rumination, which the theory correctly lists as the DMN's failure mode, is DMN-linked.
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- Bratman's nature finding is a study of nature *reducing* self-referential neural activity.
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So "we don't get enough DMN" and "nature is restorative because it quiets self-referential thought" are pulling against each other. The resolution the theory already contains — that the target is *flexibility*, not more of either mode — is the right one, but it has to be stated explicitly and early rather than left implicit. **This is the argument chapter 7 of Book One exists to make.** Handled well, it's a strength: it's the point where the book stops being another "reflect more, scroll less" book.
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---
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## Sources
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- [Bratman et al. 2015, *PNAS* — Nature experience reduces rumination and subgenual prefrontal cortex activation](https://www.pnas.org/doi/10.1073/pnas.1510459112)
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- [Yetish et al. 2015 — Natural sleep and its seasonal variations in three pre-industrial societies](https://gurven.anth.ucsb.edu/sites/secure.lsit.ucsb.edu.anth.d7_gurven/files/sitefiles/papers/yetishetal2015.pdf)
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- [Ekirch 2016, *SLEEP* — Segmented sleep in preindustrial societies](https://academic.oup.com/sleep/article/39/3/715/2454050)
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- [Traffanstedt, Mehta & LoBello 2016 — Major depression with seasonal variation: is it a valid construct?](https://journals.sagepub.com/doi/abs/10.1177/2167702615615867)
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- [Young 2017 — Does seasonal affective disorder exist? A commentary](https://journals.sagepub.com/doi/abs/10.1177/2167702616689086)
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- [Lindenfors, Wartel & Lind 2021, *Biology Letters* — 'Dunbar's number' deconstructed](https://royalsocietypublishing.org/doi/10.1098/rsbl.2021.0158)
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- [Wiradhany & Nieuwenstein 2017 — Cognitive control in media multitaskers: two replication studies and a meta-analysis](https://pubmed.ncbi.nlm.nih.gov/28840547/)
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- [Digital detox and well-being — review of evidence quality](https://pmc.ncbi.nlm.nih.gov/articles/PMC11422191/)
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- [Social media detox and well-being: a meta-analysis of RCTs](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11939267/)
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- [Killingsworth & Gilbert 2010, *Science* — A wandering mind is an unhappy mind](https://www.science.org/doi/10.1126/science.1192439)
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- [Adam & Epel 2007 — Stress, eating and the reward system](https://www.sciencedirect.com/science/article/abs/pii/S0031938407001278)
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- [Systematic review of fMRI studies on seasonal modulation of brain functional connectivity](https://www.imrpress.com/journal/BJHM/87/5/10.31083/BJHM53980)
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- [Triple network model, dynamically revisited](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7027374/)
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