In psychology, a fluency heuristic is a mental heuristic and cognitive bias in which, if one object is processed more fluently, faster, or more smoothly than another, the mind infers that this object has the higher value with respect to the question being considered. In other words, the more skillfully or elegantly an idea is communicated, the more likely it is to be considered seriously, whether or not it is logical.

Jacoby and Dallas (1981) found that if an object "jumps out" at a person and is readily perceived, then they have likely seen it before even if they do not consciously remember seeing it.

As a proxy for real-world quantities:

Hertwig et al. (2008) investigated whether retrieval fluency, like recognition, is a proxy for real-world quantities across five different reference classes in which they expected retrieval fluency to be effective.

a) cities in the U.S with more than 100,000 inhabitants

b) the 100 German companies with the highest revenue in 2003

c) the top 106 music artists in the U.S. in terms of cumulative sales of recordings from 1958 to 2003

d) the highest paid athletes of 2004