Concept · Cognitive Bias: Memory biases and distortions
Illusory truth effect
Origin: Hasher, Goldstein & Toppino, 1977
Biological Parallel
Social animals treat frequently heard alarm calls as more credible—repetition signals importance through multiple independent observations. The brain uses processing fluency (how easily information comes to mind) as a proxy for truth because familiar patterns usually reflect environmental regularities. The illusory truth effect is frequency-as-validity heuristic: what you hear repeatedly probably matters, even when the source is identical.