Moses Illusion

The Moses illusion is a semantic illusion in which people fail to notice a factual error embedded in a question because the erroneous word is closely related in meaning and sound to the correct one, first documented by researchers Thomas Erickson and Mark Mattson in 1981. In the classic example, when asked how many animals of each kind did Moses take on the ark, roughly half of respondents answer two without noticing that it was Noah, not Moses, who built the ark, an error that persists even when people are warned in advance to watch for anomalies and are given unlimited time to answer. Researchers attribute the illusion to the semantic and phonological closeness of the substituted name, since less similar substitutions are caught far more often.