Concept · Cognitive Bias: Memory biases and distortions
List-length effect
Origin: Murdock, 1962
Biological Parallel
Bees visiting 50 flowers recall individual blooms worse than those visiting 10—working memory has fixed capacity, so longer lists dilute encoding strength per item. This is attention dilution: total cognitive resources remain constant, forcing trade-offs between list length and item detail. The list-length effect explains why shorter meeting agendas yield better retention—spreading attention across 10 items leaves each weakly encoded.