Three of learning science's most robust traditions, cognitive load theory, desirable difficulties, and psychological safety, are each empirically excellent and mechanically thin. This paper argues they are local consequences of one substrate-universal constraint, bounded-capacity race-architecture, and translates that mechanics to human learning, teaching, and communication for audiences in education research, instructional design, and organisational psychology. Abstract. Three traditions of learning science — cognitive load theory and multimedia learning (Sweller, Mayer); desirable difficulties and retrieval practice (Bjork, Roediger, Karpicke); psychological safety and need-prepotency (Maslow, Edmondson) — are each empirically excellent and mechanically thin. They terminate at cognitive-architecture-as-given, representational-properties-as-given, and behavioural-information-flow-as-given. This paper proposes that the three are local consequences of the same substrate-universal physical constraints: bounded-capacity race-architecture, friction as the cost of unresolved competing routes, hysteresis as encoding-through-loading, and the Net Friction Rule as integrated-friction optimisation. The substrate-level account is empirically anchored by language-model substrates where the mechanism is mechanically visible, and the same constraints derive, rather than postulate, working-memory limits, the testing effect, the spacing effect, expertise reversal, and prepotency of safety-field activity over substantive-content processing. Implications for curriculum design, moment-by-moment classroom diagnosis, technical and organisational communication, and change management are developed. Four falsification conditions are specified. v4 changelog (June 2026). v4 adds two elements, each through external dual hostile peer-review on the addition. First, a third line of language-model evidence (§3.4): an installed low-competence disposition collapses a model's realised performance across a capacity ladder while its latent capability, measured under forced response, is unchanged — locating self-efficacy as an effort-allocation give-up threshold that gates how much of a fixed capacity is realised (the latent-versus-realised distinction; Bandura, Dweck; the expected-value-of-control account of mental effort). Second, a substrate-level reading of Piagetian constructivism (§1.3b, §2.8): assimilation, accommodation, and equilibration are given a candidate physical content as, respectively, low-friction resolution on an existing route, a contested race against the committed schema that lays new hysteresis, and the commit-pressure that discharges an open race — with falsifiable differential predictions distinguishing the two operations on both substrates, and explicit scope-conditions (operations not stage-theory; minor not major equilibration). New prior-art engagement includes Piaget (1952, 1985), Ausubel (1968), Carey (1985), Siegler (1996), Vosniadou (1994), Eccles Paper 1 (Friction Theory substrate): 10.5281/zenodo.20012654; Paper 4 (LLM calibration): 10.5281/zenodo.20059859; Paper 4B (Substrates encode experience): 10.5281/zenodo.20059861; Paper 6 (Matched friction under hysteresis): 10.5281/zenodo.20059863; Paper 7 (Forward-modelling in bounded race substrates): 10.5281/zenodo.20449154; Paper 8 (Pressure, Hysteresis, and Experience): 10.5281/zenodo.20059865; Paper 13 (Operational Friction Theory): 10.5281/zenodo.20059876; the measurement cluster — Paper 2D: 10.5281/zenodo.20562084; Paper 4C: 10.5281/zenodo.20562086; Paper 4D: 10.5281/zenodo.20562088; Paper 2E: 10.5281/zenodo.20562090; Paper 21 (measurement model of bounded-decision cognition): 10.5281/zenodo.20562415; and Paper 30 (Nature and nurture in a language model: installable value fields, intrinsic capacity), the source of the §3.4 self-efficacy result: 10.5281/zenodo.20732529. Series position. Paper 16 in the Friction Theory paper-series. Target venue: Mind, Brain, and Education (Wiley/IMBES; primary) / Educational Psychology Review (secondary) / Educational Theory (tertiary).
Tomas Pødenphant Lund (Sat,) studied this question.