When the Ends Justify the Mean: The Endpoint Leverage Effect in Distribution Perception

Previous research described different cognitive processes on how individuals process distributional information. Based on these processes, the current research uncovered a novel phenomenon in distribution perception: the Endpoint Leverage Effect. Subjective endpoints influence distribution estimations not only locally around the endpoint but also influence estimations across the whole value range of the distribution. The influence is largest close to the respective endpoint and decreases in size toward the opposite end of the value range. Three experiments investigate this phenomenon: Experiment 1 provides correlational evidence for the Endpoint Leverage Effect after presenting participants with a numerical distribution. Experiment 2 demonstrates the Endpoint Leverage Effect by manipulating the subjective endpoints of a numerical distribution directly. Experiment 3 generalizes the phenomenon by investigating a general population sample and estimations regarding a real-world income distribution. In addition, quantitative model analysis examines the cognitive processes underlying the effect. Overall, the novel Endpoint Leverage Effect is found in all three experiments, inspiring further research in a wide area of contexts.