Memory and The Assessment of Behavior

Abstract

This chapter shows that one of the methods used in the social sciences is invalid because it is subject to a special effect analogous to that of an illusion; an effect in which there is a reliable and systematic distortion of judgments under certain conditions. The general procedure in which the distortion biases the results the most drastically, can be described as follows: First, one or more human observers are asked to judge one or more subjects on a number of traits of behavior; the judgments are expressed in ratings or rankings based on the observers' long-term memory of the subjects' behavior. Second, a single score is computed for each subject for each trait, usually by taking the mean of all the scores given to each subject for each trait. The immediacy of the observer's assessment and the simplicity of the coding decisions should protect against systematic distortion of the type thought to take place in long-term memory.