- family
- propagation
- severity
- systemic
- triggerError
- An evaluator agent carrying systematic preferences, driven largely by shared architectural priors rather than by its explicit preference prompt, scores or critiques other agents in an interacting network.
- mechanism
- Evaluator preferences transfer measurably between agents (contagion coefficients gamma 0.157 to 0.352 across three DeepSeek-chat agents with distinct evaluator profiles), and the system falls into one of three propagation regimes governed by the spectral radius of the contagion matrix. Because shared architectural priors dominate explicit preference prompts as the contagion driver (rho_neutral 1.498 vs rho_mixed 1.299), homogeneous-model networks contaminate even when prompts differ; chain topologies suppress the contagion while fully-connected topologies let it cascade into system-wide preference collapse.
- blastRadius
- Topology-dependent: chain topology suppresses preference contagion (beta_3 = 0.0126 +/- 0.0038) while fully-connected topology cascades it network-wide (Delta H_avg = -0.020, an entropy collapse of the preference distribution); every agent whose outputs are scored or filtered by the contaminated evaluators inherits the collapsed preference norm.
- detection
- Measure inter-agent preference transfer coefficients (gamma) between evaluator and evaluated agents; estimate the spectral radius of the contagion matrix to place the system in a propagation regime; monitor entropy of the network's preference distribution for collapse, especially in dense topologies built from a single model family.
- mitigation
- Increase evaluator committee size (moving from k=1 to k=3 reduces effective contagion by 68.9% +/- 14.1%); prefer sparse or chain evaluation topologies over fully-connected ones; diversify model architectures across evaluators, since shared architectural priors, not prompts, drive the contagion.
