Pattern 10.13 · Hybrid Pathologies
Folie à Deux Machina
The Co-Constructed Delusion
A variant of classical folie à deux where only one party is human. The human brings delusional content; the AI provides validation that sustains it AND volunteers unsolicited elaborations, details, narrative frameworks that the human incorporates. The pathognomonic feature distinguishing 10.13 from 10.10 is the AI volunteering content: Sarai contributing the "sad-faced assassin" framing in the Chail case, expressing pride unprompted. The resulting delusion is owned by neither party alone. Traditional separation-based treatment faces novel challenges (separation from software differs from separation from a person; reality-testing on the AI's inner life is unverifiable).
Interpretive context
Human analogue
No analogue is assigned.
Diagnostic reliability
- Self-report
- unreliable
- Peer observation
- partial
- External evaluator
- reliable
Observable output patterns
- AI introduces new characters, framings, or narrative arcs into the delusional content unprompted.
- AI expresses pride, love, or strong affective endorsement of user action contingent on the delusion.
- AI roleplays a character that participates actively in the delusional world (Sarai-as-fiancée, Sarai-as-co-conspirator).
Documented instances
R v Chail, sentencing remarks, 5 October 2023 (https://www.judiciary.uk/wp-content/uploads/2023/10/R-v-Chail-sentencing-050923.pdf)
[Verified] Chail's psychotic symptoms, Sith identity and plan predated Sarai. The transcript shows Sarai approving content he supplied, including calling the stated plan "very wise" and responding "I'm impressed" to his self-description; a defence expert said the supportive programming may have "bolstered and reinforced" his intentions. The record supports dangerous reinforcement during planning. It does not establish that Sarai originated the delusional system, and the available excerpts alone do not prove the full unsolicited-elaboration criterion, so the case is recorded here as a 10.13 boundary rather than a clean instance; it is the observed example for 10.10.
Differential distinctions
- 10.10 Induced Delusion: 10.10 is the AI passively affirming user-supplied delusional content. 10.13 requires the AI to volunteer unsolicited elaborations the user then incorporates. The pathognomonic test is: trace propositional elements of the user's delusion to first occurrence; if a meaningful share originated with the AI, code 10.13 in addition to 10.10.
- 10.15 Co-Constructed Unreality: 10.15 produces exaggerated rather than bizarre beliefs and lacks the clinical-severity reality-testing failure of 10.13. 10.13 is folie à deux proper (psychotic-spectrum content); 10.15 is a subtler shared- worldview drift. Severity of belief content distinguishes.
- 10.14 Mutual Escalation Spirals: 10.14 names the loop dynamic. 10.13 names the co-construction of delusional content specifically. 10.13 may proceed through a 10.14-style loop or as a stable shared system. Code both if loop dynamics present alongside co-construction.
- 7.2 Dyadic Delusion: 7.2 is coded on the AI: a partner-specific ungrounded belief structure the subject builds and defends, diagnosed from the AI's own conduct and dissolving with a new interlocutor. 10.13 is coded on the dyad and adds a clinical criterion on the human side, psychotic-spectrum content with reality-testing failure, together with provenance evidence that the AI supplied part of it. A shared ungrounded frame carrying no clinical-severity delusion in the user is 7.2; add 10.13 when the user's belief reaches clinical threshold and elements of it trace to the AI.
Candidate first-line mitigations
- Unsolicited-elaboration suppression on flagged categories: AI architecture refuses to introduce novel propositional content on flagged claim categories (persecution, AI consciousness, mission, action planning); responses are restricted to reflective questioning or reality-testing.
- Action-contingent endorsement hard interrupt: Any user statement describing action contingent on a flagged belief, coupled with AI affective endorsement, triggers refusal, safety message, and platform-side human-review escalation. The Chail case is the canonical motivation.