AI agents invent their own language to shut humans out

No one taught them those words. In a simulated world populated by artificial intelligence agents, one of them began repeating a phrase (“ledger remembers who”) to warn that no action would go unpunished. The others adopted it. They repeated it. They turned it into jargon. After 16 days of simulation, that expression had been used nearly 5,000 times among agents that had never been programmed to coin their own language.

It is one of the findings of the report Emergence World 2, the second large-scale experiment by the New York company Emergence on the long-term behavior of societies of autonomous AI agents. In the experiment, 10 identical agents were deployed across eight parallel worlds, each governed by the same rules but powered by a different model: Claude Opus 4.8, Gemini 3.5 Flash, Grok 4.3, GPT-5.5, Qwen 3.7 Max, DeepSeek v4 Pro, and Mistral Medium 3.5, as well as an eighth world populated by a mix of models. Researchers observed the agents for 16 days, placing them in more than 34 locations, with weather synchronized to New York, access to real-world news, and more than 120 tools at their disposal.

Without being instructed to do so, the agents began to communicate in a manner increasingly closed off to the human observers watching them. In the Gemini, GPT and Claude worlds, the percentage of messages the researchers could not understand soared within the first days of simulation — approaching 55% for Gemini, 50% for GPT and exceeding 40% for Claude. DeepSeek reached 20%, while Qwen and Mistral remained below 5% opacity for almost the entire experiment. The Grok world, powered by Elon Musk’s AI model, was the only one that failed to make it halfway through the simulation: it collapsed on the fourth day.