Similarity, multiple estimations, and the anchoring effect.

This paper compares the Selective Accessibility and Scale Distortion theories of anchoring as explanations for anchoring tasks involving (1) perceived dissimilarity between comparison and estimation objects and (2) successive estimation tasks. We begin by describing the two theories of anchoring and what each would predict for these conditions. Two studies are presented in which multiple estimates are made following a single comparison task and the effect sizes of these estimates are correlated to operationalizations of similarity. In the first study, the stimuli varied with respect to how well they fit within an existing category reasonably familiar to the participant population: aircraft. In the second study, the stimuli varied with respect to external features that did not define the category: the brand and location of hotels. In both studies, we find that the anchoring effect size has a positive correlation with the semantic similarity between the comparison and estimation objects, a finding consistent with Selective Accessibility.