Attribute substitution is a psychological process thought to underlie a number of
cognitive biases and
perceptual illusions. It occurs when an individual has to make a judgment (of a
target attribute) that is computationally complex, and instead substitutes a more easily calculated
heuristic attribute. This substitution is thought of as taking place in the automatic
intuitive judgment system, rather than the more self-aware
reflective system. Hence, when someone tries to answer a difficult question, they may actually answer a related but different question, without realizing that a substitution has taken place. This explains why individuals can be unaware of their own biases, and why biases persist even when the subject is made aware of them. It also explains why human judgments often fail to show
regression toward the mean.