The Miranda Hypothesis: How Hamilton Poisoned Persona Evals - Jacob E. Thomas, Results Gen
Jun 25, 2026 · 58:17
Jacob E. Thomas argues that persona-eval benchmarks like InCharacter, which report 80.7% personality fidelity for Hamilton, structurally miss anachronistic compositing because they measure fluency and personality consistency—exactly the features the dominant cultural composite optimizes. The Miranda Hypothesis posits that training data saturated with works like the 2015 Hamilton musical (outnumbering the 175,000-word Federalist Papers by orders of magnitude) causes models to produce smoothed, morally legible composites rather than historically faithful personas. Thomas explains that RLHF amplifies this distortion because human raters share the same cultural frame. He proposes a paradigm shift to epistemic simulation: corpus-bounded, temporally-anchored systems evaluated by domain experts, with the model as a swappable component in a configurable role-playing language system. The pre-registered Prism Experiment instantiates Abraham Lincoln at four documented moments (1847, 1858, 1860, 1862–65) under three seeding conditions—bare model, biography, or primary sources—scored on a weighted three-axis rubric that prioritizes anachronism detection (40%) over voice. Thomas concludes that…
