Revealing an Unattractivity Bias in Mental Reconstruction of Occluded Faces using Generative Image Models
Frederik Riedmann, Bernhard Egger, Tim Rohe
TL;DR
The study investigates why partial occlusion increases perceived facial attractiveness by testing whether mental reconstruction during occlusion biases toward attractiveness. It combines a diffusion-based inpainting approach with a delayed matching-to-sample task to isolate reconstruction from perception. Results show that while standard attractiveness ratings exhibit an attractivity bias for occluded faces, the reconstruction task reveals an unattractivity bias, challenging the reconstruction-with-attractive-template hypothesis. This suggests that global image cues, not mental reconstruction toward attractiveness, underlie the observed FAR bias, with implications for how face perception and reconstruction processes are experimentally assessed.
Abstract
Previous studies have shown that faces are rated as more attractive when they are partially occluded. The cause of this observation remains unclear. One explanation is a mental reconstruction of the occluded face parts which is biased towards a more attractive percept as shown in face-attractiveness rating tasks. We aimed to test for this hypothesis by using a delayed matching-to-sample task, which directly requires mental reconstruction. In two online experiments, we presented observers with unattractive, neutral or attractive synthetic reconstructions of the occluded face parts using a state-of-the-art diffusion-based image generator. Our experiments do not support the initial hypothesis and reveal an unattractiveness bias for occluded faces instead. This suggests that facial attractiveness rating tasks do not prompt reconstructions. Rather, the attractivity bias may arise from global image features, and faces may actually be reconstructed with unattractive properties when mental reconstruction is applied.