Sensitivity to Weight Changes of Others Depends on Personal Body Size

Previous research has suggested that own body size estimates are biased towards an average reference body (Cornelissen, Bester, Cairns, Tove´e Cornelissen, 2015). The role of personal body size in body size perception of others is still unclear. In this study, we tested healthy females varying in body mass index (BMI) to investigate whether personal body size influenced accuracy of body size estimation and sensitivity to weight changes of others. We generated four biometric female avatars with BMIs of 15, 25, 35, and 45 and altered the weight of the avatars (5, 10, 15, and 20 BMI change) based on a statistical body model. In several psychophysical experiments, we presented the stimuli on a stereoscopic, large-screen immersive display. For each avatar series, participants memorized what the original body looked like and then responded for each of the presented bodies whether it was the same as the one memorized. Our results show that there was no influence of personal BMI on the accuracy of body size estimation of the avatars. Interestingly however, participants were more sensitive to weight changes of an avatar close in BMI to their own, suggesting that own body size influences perception of others’ weight