Omission Bias
The tendency to judge harmful actions as worse, or less moral than equally harmful omissions (inactions) because actions are more obvious than inactions.
EverydayConcepts.io
Origin
Jonathan Baron of the University of Pennsylvania, together with colleagues Mark Spranca and Ilana Minsk, formally named and studied omission bias in a 1991 paper, "Omission and Commission in Judgment and Choice," published in the Journal of Experimental Social Psychology. Using moral dilemma scenarios — including an infamous tennis player poisoning case — they demonstrated that identical harmful outcomes were rated less wrong when caused by inaction. Baron had been examining related moral asymmetries in decision-making research throughout the 1980s.
Updated February 22, 2026