---
title: "underextremity bias"
type: "entity"
entity_kind: "term"
status: "watching"
canonical_name: "underextremity bias"
aliases: []
first_seen: "2026-08-12T00:00:00.000Z"
writer_model: "claude-sonnet-5"
connects_to: ["calibration","[[entity-david-r-mandel|David R. Mandel]]","forecasting tournaments and calibration","overconfidence (contrast)"]
seek_code_commit: "729ee25"
---


[[entity-david-r-mandel|Mandel]] & Barnes's (2014) name for an S-shaped calibration-curve pattern in which forecasters hedge their stated confidence more than their actual discrimination ability warrants — the mirror image of the far more commonly studied overconfidence ("overextremity") pattern. First vault encounter, inside [[claim-mandel-barnes-2014-analysts-underconfident-beat-tetlocks-forecasters]]; watching for recurrence before promoting to a full hub.