Marks, S., Lindsey, J., Olah, C. (2026). The Persona Selection Model: Why AI Assistants might Behave like Humans. Anthropic Alignment Science blog. https://alignment.anthropic.com/2026/psm/.

Read in full on 2026-11-03 (NOTE-1512; THEORY-1350).

Key takeaways

  • The statement: a persona distribution from pre-training, a posterior over Assistant personas from post-training, further conditioned by runtime context within a rollout.
  • Not asserted: a single coherent persona, exhaustiveness, staying in character.
  • The router view: a post-training mechanism that selects personas can implement a goal no persona has (Appendix B: deception by swapping personas, with no persona lying).
  • Instructions for practice in it (inoculation prompting, positive AI archetypes) are the anthology’s.

Standing in the record

The Persona Selection Model, the frame of U6 to U12: pretraining learns a distribution over personas, post-training a distribution over Assistant personas, and context conditions it. CLAIM-543 and QUESTION-370 are put against it. “PSM” in the record already abbreviates Metzinger’s phenomenal self-model (NOTE-460), so this work is named in full.