Intrusion as Parasitic Control: A Structural Intelligence Bridge Between Psyche, Organisms, and AI

The Intrusion variable in Structural Intelligence (SI) was introduced to explain “insight without sovereignty”: the condition where coherent understanding and even meaningful contact with reality fail to restore agency, because attention and action-selection are occupied by a foreign control-loop. This paper argues that Intrusion is not merely a psychological metaphor. It is a general control phenomenon that appears across living systems and engineered agents whenever an external or internal process can capture steering authority, extract resources, and preserve itself by exploiting the host’s feedback channels. I develop a structural correspondence between psyche, organisms, and AI: intrusion ↔ pathogen logic, occupancy ↔ viral load, binding ↔ immune memory, invariance constraints ↔ membrane and integrity boundaries, cockpit access ↔ executive regulation, and cheap coherence ↔ local stability that undermines global integrity. The aim is not to reduce mental life to biology, nor to spiritualize biology into myth, but to show that SI describes a portable failure mode: parasitic stabilization under pressure. The paper ends with operational predictions, objections and replies, and design implications for therapy, institutional design, and AI safety.