Reorganise into two books plus shared theory and essays

theory/                 EVIDENCE.md + THEORY.md, shared by everything
  a-days-walk/            Book One: CHAPTERS, CRAFT, FIELD_BRIEF, OUTLINE, drafts/
  seasonal-intelligence/  Book Two: OUTLINE
  essays/                 the six pieces
  archive/                superseded originals, unmaintained by design
  PORTFOLIO.md            the split and the sequence

Adds a README to each directory. Cross-references updated to the new
layout; archive/ references left broken deliberately, as those are
historical documents.

Also revises chapter 6 of Book One: the notification scene is now four
items rather than four hundred, since the narrator is a light user. The
low volume is stronger evidence than a flood would have been - it is the
case the attention-economy account cannot explain. Tracked as A26 in the
argument ledger, planted in the prologue and chapter 1.

theory/EVIDENCE.md

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+# Evidence tiers
+
+*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.*
+
+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.
+
+---
+
+## Tier A — Well-supported. State it, cite it, move on.
+
+**The brain conserves energy by reusing models rather than building them.**
+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.
+
+**DMN and TPN exist, and are broadly anticorrelated.**
+Standard, replicated resting-state neuroimaging. Safe.
+
+**The salience network exists and is implicated in switching between them.**
+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.
+
+**Nature exposure reduces rumination.**
+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.
+
+**Chronic stress raises appetite for energy-dense food.**
+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.
+
+**Seasonal variation in brain response to cognitive tasks is real.**
+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.
+
+**Segmented sleep in pre-industrial Western Europe.**
+Ekirch's historical documentation is solid *for that time and place*. See Tier B for the overreach.
+
+---
+
+## Tier B — Contested. You must present the dispute, in the text.
+
+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.
+
+**Biphasic sleep as a universal human pattern — no.**
+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.
+
+**Seasonality of mood — much weaker than folk belief.**
+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."
+
+**Dunbar's number.**
+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.**
+
+**Media multitasking impairs attention — small and inconsistent.**
+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.)*
+
+**Digital detox — and this one helps you.**
+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.
+
+---
+
+## Tier C — Plausible, untested. Mark as hypothesis, in the text.
+
+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.
+
+- **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.
+- **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.
+- **Salience-network flexibility as the lever**, rather than favouring reflection or focus. The theory's central practical claim.
+- **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.
+- **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.
+- **Work-life balance complaints as switching failures rather than time-allocation failures.**
+- **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.
+
+---
+
+## Tier D — Speculative or personal. Cut, or flag explicitly as speculation.
+
+**Cut entirely:**
+
+- **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.
+- **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.
+- **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.
+- **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.
+
+**Demote to explicit metaphor:**
+
+- **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.
+
+---
+
+## The internal contradiction to resolve before drafting
+
+The current theory treats DMN activity as the thing modern life starves us of, and therefore as good. But:
+
+- 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.
+- Rumination, which the theory correctly lists as the DMN's failure mode, is DMN-linked.
+- Bratman's nature finding is a study of nature *reducing* self-referential neural activity.
+
+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.
+
+---
+
+## Sources
+
+- [Bratman et al. 2015, *PNAS* — Nature experience reduces rumination and subgenual prefrontal cortex activation](https://www.pnas.org/doi/10.1073/pnas.1510459112)
+- [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)
+- [Ekirch 2016, *SLEEP* — Segmented sleep in preindustrial societies](https://academic.oup.com/sleep/article/39/3/715/2454050)
+- [Traffanstedt, Mehta & LoBello 2016 — Major depression with seasonal variation: is it a valid construct?](https://journals.sagepub.com/doi/abs/10.1177/2167702615615867)
+- [Young 2017 — Does seasonal affective disorder exist? A commentary](https://journals.sagepub.com/doi/abs/10.1177/2167702616689086)
+- [Lindenfors, Wartel & Lind 2021, *Biology Letters* — 'Dunbar's number' deconstructed](https://royalsocietypublishing.org/doi/10.1098/rsbl.2021.0158)
+- [Wiradhany & Nieuwenstein 2017 — Cognitive control in media multitaskers: two replication studies and a meta-analysis](https://pubmed.ncbi.nlm.nih.gov/28840547/)
+- [Digital detox and well-being — review of evidence quality](https://pmc.ncbi.nlm.nih.gov/articles/PMC11422191/)
+- [Social media detox and well-being: a meta-analysis of RCTs](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11939267/)
+- [Killingsworth & Gilbert 2010, *Science* — A wandering mind is an unhappy mind](https://www.science.org/doi/10.1126/science.1192439)
+- [Adam & Epel 2007 — Stress, eating and the reward system](https://www.sciencedirect.com/science/article/abs/pii/S0031938407001278)
+- [Systematic review of fMRI studies on seasonal modulation of brain functional connectivity](https://www.imrpress.com/journal/BJHM/87/5/10.31083/BJHM53980)
+- [Triple network model, dynamically revisited](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7027374/)

theory/README.md

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+# Theory
+
+The shared foundation. Both books and all six essays rest on these two files.
+
+| File | What it does |
+|---|---|
+| **`EVIDENCE.md`** | Every load-bearing claim sorted into four tiers, with sources. **Governs what may be asserted anywhere in the project.** |
+| `THEORY.md` | The Relevance Theory itself — the argument, narrowed to what the evidence supports, with the cut material and reasons at the end. |
+
+## The tiers
+
+| Tier | Meaning | How to write it |
+|---|---|---|
+| **A** | Well-supported, multiple sources | State it, cite it, move on |
+| **B** | Contested — real dispute in the literature | Present both sides *in the text* |
+| **C** | Plausible, untested — the author's hypothesis | Mark as hypothesis, in the text, every time |
+| **D** | Speculative or personal | Memoir or metaphor; cannot carry an argument |
+
+**The failure mode this exists to prevent is a Tier C claim written in a Tier A voice.** The original contribution — the three-distance relevance model — is Tier C in its entirety. Saying so plainly, in the text, is what makes the rest of the book believable.
+
+## Two things in `EVIDENCE.md` worth knowing without opening it
+
+**There is an internal contradiction that has to be resolved before drafting.** The theory treats default-mode activity as the thing modern life starves us of, and therefore good. But mind-wandering predicts *lower* momentary happiness (Killingsworth & Gilbert 2010), rumination is default-mode-linked, and the best experiment in the literature (Bratman 2015) found nature helping by *quieting* self-referential thought. "We need more reflection" and "nature helps by reducing it" cannot both stand. The resolution — that the target is flexibility, not more of either mode — is chapter 7's job in Book One.
+
+**Several claims were cut and should not creep back.** The foreign-policy argument, the weight-loss protocol, the diagnostic test's numeric scoring, the "I"/"me" labels for the networks, and the seasonal network mapping. Each has its reason recorded at the end of `THEORY.md`. If one reappears in a draft, that draft has regressed.

theory/THEORY.md

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+# The Relevance Theory
+
+*The theory behind the project, revised July 2026 to match what the evidence actually supports. The previous version is preserved at `../archive/THEORY_v1.md`. Evidence tiers referenced throughout are defined in `EVIDENCE.md`.*
+
+**Renamed** from "Cognitive Balance Theory." The old name described the wrong thing — the theory isn't about balancing two modes, it's about how the brain decides what deserves attention at all. The relevance-sorting claim is the original contribution; the network model is borrowed scaffolding.
+
+---
+
+## The claim, in one paragraph
+
+Thinking costs energy, so the brain triages incoming information rather than processing it evenly. It evolved a rule for triage based on **proximity, confirmability, and actionability** — three tiers of relevance corresponding roughly to what you could walk to, what you could ride to, and what lay beyond. Modern media delivers information from the third tier while carrying every signal the brain uses to identify the first. The result is not distraction but misfiling: sustained, physiologically real concern about matters no action of yours can touch. The remedy is not consuming less but re-sorting deliberately.
+
+Everything below either supports this or is scaffolding for it.
+
+---
+
+## Part 1 — The thrifty brain
+**Tier A. This part is solid and can be asserted.**
+
+Everything alive runs on an energy budget, and cognition is expensive. The brain therefore predicts rather than perceives, reuses models rather than constructing them, and reaches for heuristics rather than deliberation wherever it can get away with it. This is why optical illusions work at all: you are seeing a prediction, corrected by input, not input itself.
+
+The same economy operates at high levels. Stereotypes and generalisations about people are the identical mechanism running on social categories — uncomfortable to say, but the discomfort is about the consequences, not the mechanism.
+
+Three independent traditions converge here: predictive processing and the free energy principle (Friston, Clark), cognitive miser theory (Fiske & Taylor, 1984), and System 1 / System 2 (Kahneman). The theory doesn't need to re-derive any of this — it needs to cite it and build on it.
+
+**The consequence that everything else rests on:** a brain this economical *must* triage. It cannot afford to evaluate every input on its merits. So it needs a cheap rule for deciding what to spend on. Part 2 is a proposal about what that rule is.
+
+---
+
+## Part 2 — The three tiers of relevance
+**Tier C. This is the original contribution and it is untested. Both halves of that sentence matter.**
+
+Nobody has tested this model. It emerged from reasoning about what information environments looked like for most of human history, and it may be wrong. It is presented as a hypothesis that generates predictions, not as a finding.
+
+**Tier one — within a day's walk.** Direct effect on you, personally confirmable, and actionable. A flooded road, a neighbour's illness, a fire. Two properties always travel together here: you can check it, and you can do something about it. The proposal is that the salience machinery was calibrated on this tier.
+
+**Tier two — within a day's ride.** Indirect effect, arriving through people you know, usually unverifiable but reasonably trusted. Prices, disputes, news from the next valley. Not directly actionable, but it is what context is made of — it's how tier-one facts acquire meaning. Trust here is social rather than evidential, which is a mechanism rather than a defect.
+
+**Tier three — beyond the horizon.** Unconfirmable and unactionable. Wars, famines, rulers, catastrophes.
+
+**The historical observation the theory rests on:** every culture before ours had a tier three, and handled it deliberately — story, myth, rumour, ballad, sermon. That handling was not a failed attempt at accurate reporting. *The form was the filing.* Distant news arrived wrapped in markers of its own distance, and you knew from how it reached you that it was not something to act on before nightfall.
+
+---
+
+## Part 3 — The collapse
+**Tier C.**
+
+Modern media delivers tier-three information carrying tier-one signals: present tense, high definition, real time, human faces at conversational distance, and notifications indistinguishable from ones about your own family. Every marker the machinery used to separate near from far has been stripped or inverted.
+
+This did not happen through malice or even primarily through commercial design. It happened through the ordinary logic of media getting better. **Improved delivery is the mechanism.** A war photographed and transmitted in seconds is a genuine technical achievement that also happens to defeat a filtering system built over a hundred thousand years.
+
+This reframes the standard critique of social media. The reward-hacking account is true but shallow. The deeper harm is that these platforms destroy the tier distinction and then require you to switch between tiers several times a minute — a war, a friend's baby, a work message, a stranger's opinion, all arriving through the same slot with the same weight.
+
+---
+
+## Part 4 — The actionability gap
+**Tier C. The least developed idea here and possibly the most valuable.**
+
+The distinctive modern injury is not distraction. It is **caring intensely about what you cannot touch** — genuine, physiologically real concern about matters no action of yours can affect, repeated daily, for years.
+
+Tier-one information always came with something to do. Tier-three information historically came without urgency. Modern tier-three information arrives with the urgency and without the action. That specific combination — high salience, zero agency — has no evolutionary precedent and no inherited cultural handling.
+
+What it produces: helplessness, compassion fatigue, moral exhaustion, and the particular shame of scrolling past a catastrophe.
+
+**The necessary guardrail:** this is not an argument for caring less about distant suffering. It is an argument that caring without any channel for action is a state we have engineered at civilisational scale and never designed for. The response is to build channels, or to consciously accept some knowledge as knowledge rather than as summons — not to narrow the circle of concern. Any version of this theory that ends in "stop caring about far-away people" has gone wrong.
+
+---
+
+## Part 5 — The network scaffolding
+**Tier A on the anatomy, Tier C on the interpretation. Borrowed, not original. Keep it contained.**
+
+Three networks, in plain language:
+
+| Network | What it does | Failure mode |
+|---|---|---|
+| **Default mode** | Reflection, narrative, autobiographical memory, mind-wandering | Rumination, paralysis |
+| **Task-positive** | Focus, execution, external monitoring | Anxiety, burnout, depletion |
+| **Salience** | Detects what matters; mediates between the other two | Poor prioritisation, false urgency, switching failure |
+
+Menon's triple-network model is well-supported, with causal evidence for the salience network's mediating role from dynamic causal modelling and related methods. But **these are functional networks that overlap and co-activate, not discrete modules with a switch.** "Switchboard" is a metaphor used knowingly. State this once, clearly, and the metaphor is then earned.
+
+**The load-bearing interpretive claim (Tier C):** salience-network *flexibility* is the lever — not favouring reflection over doing, or the reverse.
+
+### The contradiction this resolves
+
+The obvious version of this theory says modern life starves us of default-mode activity and we need more of it. That version is wrong, and the evidence says so:
+
+- Mind-wandering — the default mode's signature activity — predicted *lower* momentary happiness in Killingsworth & Gilbert's 2010 experience-sampling study, accounting for more variance in wellbeing than what people were actually doing.
+- Rumination, the default mode's failure state, is one of the more reliable predictors of depression risk.
+- The best experimental result in this whole literature (Bratman et al. 2015) is a finding that nature *reduced* self-referential neural activity — the good outcome came from less of it, not more.
+
+So "reflect more" is not the prescription, and any version of this theory that lands there has misread its own evidence. The target is the capacity to switch appropriately, which is precisely what tier collapse degrades. This is the point where the theory stops resembling every other book about slowing down.
+
+---
+
+## Part 6 — What follows in practice
+**Tier C, except where noted.**
+
+**Retriage, not abstinence.** The practice is one question asked at the moment of contact: *is this within a day's walk?* Tier-three information isn't forbidden; it's re-filed. You may know about the war; you may not treat knowing as acting.
+
+**The evidence supports this over quitting** (Tier B, and it favours you): review evidence on digital detox is poor quality overall, total abstinence has the weakest record of any approach, several studies find harm during the detox, and interventions that change *how* people engage outperform those that merely reduce exposure. Abstinence fails because it treats the problem as volume. It's structure.
+
+**Restore the stripped markers.** Read distant news in text, in past tense, at a delay, in longer form. Form was always the filing system; you can reinstate it manually.
+
+**Low-salience environments.** Tier A, and the strongest practical claim available: ninety minutes in a natural setting reduced rumination and subgenual prefrontal activation; ninety minutes in an urban setting did neither (Bratman et al. 2015). Same duration, same effort — the setting did the work. The strong version, that 5,000 steps somewhere quiet beat 10,000 in a corridor, is Tier C but sits on a solid foundation. A forest is one of the last environments most people enter where nothing is pretending to be urgent.
+
+**Desk hunger.** A personal observation worth keeping: sustained focused work produces hunger with no exertion, while multi-day walking produces little despite heavy exertion. Chronic stress raising appetite for energy-dense food is Tier A (Adam & Epel, 2007, and the cortisol-reactivity literature). The specific interoceptive-suppression mechanism proposed here is Tier C — a guess, and should be written as one. It is good essay material and not a basis for advice.
+
+---
+
+## What was removed from v1, and why
+
+- **The foreign-policy argument** (that task-positive-dominant societies bias toward interventionism). Unfalsifiable and politically loaded. One quotation from it would discredit the rest.
+- **The weight-loss protocol.** A prescriptive four-anchor health regimen resting on an invented mechanism, aimed at readers who may include vulnerable people. "Weight regulation follows nervous-system safety, not willpower" is an unsupported clinical claim. The underlying observation survives as an essay; the protocol does not.
+- **The diagnostic test's scoring.** Numeric thresholds derived from a single respondent create false clinical precision. The twenty questions survive as unscored reflection prompts.
+- **The "I" / "me" labels.** They invert most readers' intuitions, add no explanatory power, and cost a paragraph of defence every time they appear.
+- **The seasonal network mapping.** No evidence supports the specific assignment and Meyer et al. 2016 points elsewhere. It survives in Book Two as an explicitly declared design metaphor.
+
+## What the theory still needs
+
+1. **Any test at all of the tier model.** Even a small study — do people report different physiological and emotional responses to identical information framed as local versus distant? This is genuinely testable and nobody has done it.
+2. **A worked account of the actionability gap** distinct from the existing compassion-fatigue literature, which covers adjacent ground from a clinical angle.
+3. **Case studies** for the workplace and seasonal claims. Currently argument without instances.
+
+---
+
+## Where the theory sits relative to existing work
+
+Ideas here with real academic lineage, to cite rather than re-derive: cognitive miser theory (Fiske & Taylor); predictive processing (Friston, Clark); System 1/2 (Kahneman); media ecology (McLuhan, Postman, Carr); the narrative-noise critique (Taleb); context collapse (boyd, Marwick, Turkle).
+
+**Use with care:** Dunbar. The idea of a bounded social world is usable; the number is not. Lindenfors et al. 2021 re-derived it with modern methods and got confidence intervals spanning 2 to 520, meaning no specific figure is defensible.
+
+The genuinely novel piece is the three-tier relevance model and the actionability gap that follows from it. Everything else is assembled from existing work — which is fine, and worth saying openly, because the assembly is the contribution.