High Trust as a Compositional Regime

We study high trust not as a psychological or moral property, but as a system-level regime: a configuration in which coordination, verification, and enforcement costs are reduced by assumption rather than continuously incurred.

The systems of interest—human societies and autonomous systems alike—are modeled as collections of interacting components evolving over time. Interactions occur locally, under partial information, and must compose into consistent global behavior. The central question is:

Under what conditions can locally trusting interactions compose into global system behavior without correlated failure?

A high trust regime is one in which such composition holds.

Core Object

A system operates in a high trust regime if it satisfies the following property:

Local trust assumptions compose into global behavior, and violations remain contained.

This property concerns interaction structure, not participant intent.

Governing Invariant

The governing invariant of a high trust regime is:

Trust assumptions do not introduce coupling whose violation propagates beyond the scope of the assumption.

This requires three conditions on trust assumptions:

1. Scoped: each assumption specifies which components, interfaces, and failure modes it covers.
2. Compositional: if assumptions $A$ and $B$ are independently safe, their conjunction $A \land B$ does not introduce new propagation paths.
3. Failure-bounded: violation of an assumption triggers response within a defined cost and scope; no assumption failure requires global rollback.

Consequences

From this invariant follow structural consequences:

1. Cost shift: ongoing coordination cost decreases; sensitivity to assumption violation increases.
2. Enforcement locus: continuous verification is replaced by interface constraints with explicit recovery procedures.
3. Noninterference: private state cannot influence behavior outside its interface boundary. (This is the information-flow property that parametric and capability-based designs enforce by construction.)
4. Signal hygiene: trust signals (reputation, attestation, adjudication outcomes) compose additively and decay—they neither inflate without bound nor persist without refresh.

Collapse Dynamics

High trust regimes fail by threshold, not erosion. The mechanism:

1. Latent assumption debt: unverified assumptions accumulate as the system operates successfully under benign conditions.
2. Trigger: a local violation occurs that the assumption ruled out.
3. Correlated failure: because assumptions were scoped implicitly or shared hidden dependencies, the violation propagates.
4. Regime shift: the system reverts to high-verification operation, incurring the coordination costs that trust had deferred.

Recovery depends on whether the system was designed for violations to be detectable, attributable, and reversible.

Design Implication

High trust cannot be directly mandated. It emerges from systems designed so that:

• cooperation incurs lower cost than defection (incentive alignment),
• defection is detectable before propagation (observability),
• detected violations are containable and repairable (recovery design).

Design determines whether trust assumptions are warranted—whether granting them yields the efficiency benefit without the tail risk.

Scope

This framework applies to systems where:

• efficiency benefits from reduced verification under non-adversarial base rates,
• interactions are repeated or reputation-carrying,
• failure modes are designable (not exogenous shocks).

It does not apply to:

• single-shot interactions (no reputation, no iteration),
• fully adversarial environments (trust assumptions are false by construction),
• systems requiring continuous global consistency (trust offers no efficiency gain).