Intervening Variables

Abstract

Abstract The term “intervening variable,” as used by behavioral theorists such as Clark Hull and Edward Tolman, describes a variable that mediates the relationship between a stimulus and response (Hilgard, 1958). Behavioral theorists were not consistent in their use of the term intervening variable and often disagreed about what even constituted an intervening variable. At the heart of the controversy was whether intervening variables that were hypothetical entities could be considered scientific or whether allowing hypothetical entities threatened the rigor and objectivity of behavioral science. During this time American behavioral scientists wanted psychology to be a natural science and thus aligned themselves (often in name only) with the logical positivists (Smith, 1986). Consequently, ideas that smacked of subjectivity or that allowed for the positing of hypothetical entities that could not be empirically verified were met with resistance and skepticism.