Abstract
A common sight in life is seeing other people walk, and our visual systems specialize in processing such actions. Notably, we are not only quick to recognize actions, but also quick to judge how elegantly people walk. What movements lead to an appealing impression, and why do we have such aesthetic experiences? Do aesthetic preferences for body movements arise from perceiving others’ positive emotions? To answer these questions, we showed 150 observers different point-light walkers who expressed neutral, happy, angry, or sad emotions through their movements. Three experiments were conducted to measure the observers’ impressions of aesthetic appeal, emotion positivity, and naturalness of the intact walkers and spatially scrambled point-light displays. We discovered three patterns: (a) When the emotion categories are rendered unrecognizable through spatial scrambling, observers preferred stimuli with faster joint motions. (b) For intact walkers, the more positive the walkers’ emotions appeared, the more aesthetically pleasing they were. (c) Intriguingly, despite the general aesthetic preference for positive emotions, observers gave higher aesthetic ratings for neutral walkers than walkers with other emotions both before and after regressing out the influences of emotion positivity. The aesthetic preference for neutral walkers can be explained by a computational model that captures movement prototypicality. The model used a dynamic time warping algorithm to assess trajectory dissimilarity among walkers, and showed that an aesthetic preference for prototype accounted for the neutral walker preference. The model also predicted both the perceived typicality of walkers (measured by their naturalness ratings) and the aesthetic experiences from different walkers in general. These findings imply possible functions for action aesthetics beyond preferring happy conspecifics: Atypical actions may signal sickness or ill intentions, and thus, liking prototypical agents (or disliking atypical agents) may aid us in avoidance of potential dangers.