Concept · Cognitive Bias: Persuasion and influence biases
Barnum effect (Forer effect)
Origin: Forer, 1949
Biological Parallel
Aposematic signals (warning coloration) work because they're generic—bright colors mean 'danger' across thousands of toxic species. The effectiveness lies in vagueness: predators learn one pattern and apply it broadly. Mimicry exploits this: harmless species display generic warning signals and gain protection. The Barnum effect is pattern-matching bias: accept generic signals as specific when the cost of discrimination exceeds the benefit. Evolution favored fast categorization over nuanced analysis.