Abstract: Compatibility exists between positive/negative stimuli and approach/avoidance behaviors. Existing studies disagree on the definition of approach-avoidance behaviors, sometimes confusing them with other types of behaviors. Using “representational distance change” as a critical criterion can help settle the controversy. Motivation orientation theory is by far the best theoretical framework in explaining the compatibility effect of approaching the positive and avoiding the negative, whereas event coding theory and specific muscle activation account are not as suitable. A new paradigm, exploring compatibility effect with mouse trajectory, may combine the merits of different previous paradigms, and thus has its unique advantages.

Key words: compatibility effect, approach-avoidance behavior, motivation orientation theory, event coding theory, mouse trajectory