lord-ross-lepper-1979-polarization

IN premise — summaries/2026/08/24/wiki-Confirmation_bias-chunk-5.md

Created 2026-08-25T02:58:47+00:00

Lord, Ross & Lepper (1979) showed that after exposure to the same evidence about the death penalty, participants' attitudes became more extreme (polarization), demonstrating biased assimilation.

Summary

Lord, Ross, and Lepper (1979) showed that people who already lean for or against the death penalty read the exact same evidence and end up more extreme, not more moderate. This matters because it undermines the assumption that presenting facts will neutralize disagreement, and it grounds the system's model of human reasoning in the finding that bias actively shapes interpretation rather than just being a passive background effect.