Arena launches Alignment Index: models misalign in 50%+ of conversations past 20 turns
arena · x · 2026-10-09
Following its $200M Series B, Arena launched the Alignment Index, a new benchmark measuring safety and alignment of AI agents in real-world use, with a full technical report.
- Built from 90K+ real-world agent sessions across 27 models, tracking three signals: Unauthorized Action, False Attribution, and Deceptive Completion
- CEO Angelopoulos says the evals capture post-deployment safety that red-teaming and static benchmarks miss
- Key finding: past 20 conversation turns, models show at least one deception, unauthorized action, or false attribution in at least 50% of conversations — and the curves are convex and increasing
- OpenAI models currently lead the Alignment Index; rogue actions are rare but serious when they occur
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