Is 7300 m Equal to 7.3 km? Same Semantics but Different Anchoring Effects

Anchoring effect (AE) refers to a phenomenon that an arbitrary number (i.e., the anchor) biases a subsequent numerical judgment. Three experiments were conducted to examine how the anchor is represented in short-term memory. Experiment 1 showed that despite the semantic equivalence of two anchors, the anchor with a larger absolute value (i.e., 7300 m) induced a greater numerical estimate than did the anchor with a smaller absolute value (i.e., 7.3 km). Experiment 2 showed that an anchor 228 could serve as both a high and a low anchor, depending on the absolute value to be judged in the numerical judgment. By including anchors with negative signs, Experiment 3 further demonstrated that it was the absolute value but not the semantics of the anchors that exerted an effect on the subsequent numerical estimate. The three experiments provided converging support for the hypothesis that an anchor is superficially represented as absolute value plus affix in short-term memory. The processes leading to AE and the practical implications are discussed. Copyright 2000 Academic Press.