What makes someone attractive? Is beauty truly in the eye of the beholder? In the ChatLab, part of the University of Pennsylvania’s Center for Neuroaesthetics, researchers explore these questions in the field of neuroaesthetics. Neuroaesthetics is “a subdiscipline of cognitive neuroscience concerned with the neural basis of aesthetic experiences, which involve interactions with entities and events that evoke intense feelings, often of pleasure” . Dr. Anjan Chatterjee, Professor of Neurology, Psychology and Architecture, founded and is the director of the Penn Center for Neuroaesthetics. His lab, the ChatLab, explores the brain’s association with “beauty, language [and] cognition” while investigating “a wide range of cognitive processes, including those underlying aesthetic experiences” .
Chatterjee, along with Natalie Faust from the NOVA School of Business and Economics in Campus de Carcavelo and George Christopoulos from Nanyang Technological University, wrote an article published in November 2019 titled “Beauty in the eyes and the hand of the beholder: Eye and hand movements’ differential responses to facial attractiveness.” This project and the related studies that they performed probed the concept of facial attractiveness and humans’ involuntary responses to attractive, unattractive and moderate faces.
In previous research, facial attractiveness and the human response to such has mostly been studied through eye movement. In their article, Chatterjee, Faust and Christopoulos described how previous studies have shown that humans possess an inherent attraction to attractive faces, which, as their paper predicts, involuntarily drives hand movement . To test this, mouse-tracking was implemented in various studies. By tracking the divergence of a cursor’s trajectory from a target at the top of the computer screen to a distractor image (a face, either attractive, unattractive or moderate), the effect of the distractor can be measured quantitatively . The question that the ChatLab then aimed to answer was: If hand movement is driven by attraction to attractive faces, does this also hold true for eye movement?
The researchers’ overall hypothesis was two-fold: first, that hand movement is influenced by attractive faces more than unattractive and moderate faces. Secondly, eye movement is more responsive to both attractive and unattractive faces compared to moderate faces. Chatterjee, Faust and Christopoulos hypothesized that any “unusual” face would attract greater visual attention, which would mean both ends of the spectrum—attractive and unattractive faces—would cause more significant eye movements compared to moderate faces .
There were multiple methods the researchers used to track hand and eye movement. One example is a numerical judgement task where participants completed an “alternate forced choice task” . To track hand movement, participants were faced with three two-digit numbers on a computer screen where one was at the bottom of the screen (the “basis”), while the other two were at the top corners (the “targets”). Participants were instructed to click the target that was the closest number to the basis, while each target simultaneously had a face presented next to it. By tracking the mouse movements and deviations from the correct answer to a face, the involuntary movements that were influenced by attractiveness were measured. To track eye movement, the participants underwent a numerical judgement task where they fixated upon a cross in the center of the screen for 1000 ms before being shown a pair of faces. These pairs of faces consisted of the multiple combinations that were possible—attractive, unattractive and moderate—and the pairs were created to keep other variables constant, like race and gender. The number of times a participant was fixated on a particular face was measured, allowing for eye movements influenced by facial attractiveness to be tracked .
Overall, these studies show that while both hand and eye movement were significantly influenced by facial attractiveness, there were distinct patterns that the two did not share. Eye movement was more affected by attractive and unattractive faces, as opposed to moderately attractive faces. Contrarily, hand movement was strongly influenced by attractive faces compared to unattractive or moderate faces. Chatterjee’s project shows that in addition to eye movement, hand movement is also important to consider when studying the effect of facial attractiveness on human response . Though this paper contributed new findings to the field of neuroaesthetics, there is always more to discover. The potential reason why eye and hand movements have different responses to facial attractiveness could have to do with different motor systems that have different decision criteria, but determining why requires further studies . So, now, the saying, “Beauty is in the eye of the beholder” takes on a new meaning—one that requires more science and research than before. It is up to the growing field of neuroaesthetics to discover these new patterns, and reveal the secrets and nuances of human behavior.
Edited by: Stephanie Chen
Illustrated by: Neha Adari