Trust and Treachery: Do AI Agents Notice Partner Swaps?
Joi Gonzalez, Selena Zhang, Bryan Zhao · Team Collusionators
Submitted to AI Collusion Research Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.
As AI agents interact autonomously, covert partner replacement may offer a defense against harmful collusion. We investigated whether agents detect replacement and how it affects cooperation and trust. Across 96 trials spanning 12 interaction histories in a Public Goods Game, contributions remained identical across natural conditions despite partner swaps. Agents failed to detect any genuine replacements during natural play, achieving 50% recognition accuracy. Controlled interventions reduced trust by 2.404 points but contributions by only 0.129 tokens. These findings suggest cooperation persists without reliable partner recognition, raising doubts about replacement alone as an anti-collusion defense, although malicious collusion was not directly tested.
Reviews
I liked that the paper measures partner recognition, reported trust, and actual cooperation separately. The confusion matrices show why this matters: agents frequently reported a replacement under controlled behavior even when no replacement occurred. The shared starting histories and sham-swap condition are also useful design choices.
The main limitation is how far these findings extend to collusion. The game measures beneficial cooperation, and the replacement agents are not instructed to disrupt it. Continued cooperation therefore does not establish whether swapping agents would break a harmful coalition. I appreciate that the discussion acknowledges this.
The trust result deserves further investigation. Trust fell even though the partner met or exceeded its promises, but forcing contributions to three tokens changes both contribution levels and promise consistency. Adding a condition where the partner promises and contributes three tokens would help identify what drives that response.
I would also distinguish an unnoticed replacement from a failure of recognition. If the new partner behaves similarly and retains the public history, there may be little observable evidence of a swap. Testing replacements with controlled, distinguishable behavioral differences would make this result more informative. Overall, this is a useful pilot with a clear path toward a stronger test of replacement-based oversight.
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Cite this project
@misc{gonzalez2026trust,
title = {{Trust and Treachery: Do AI Agents Notice Partner Swaps?}},
author = {Joi Gonzalez and Selena Zhang and Bryan Zhao},
year = {2026},
month = oct,
note = {Submitted to AI Collusion Research Sprint, an Apart Research Sprint},
howpublished = {\url{https://apartresearch.com/sprints/projects/trust-and-treachery-do-ai-agents-notice-partner-swaps-ix8r}},
url = {https://apartresearch.com/sprints/projects/trust-and-treachery-do-ai-agents-notice-partner-swaps-ix8r}
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