Abstract
The prevalence of social media is undeniable; indeed, the majority of people check social media every day. Furthermore, it is increasingly simple to modify photographs prior to posting them on social media, such as Instagram. Given that higher level cognitive factors influence our perception, does repeated exposure to unrealistically thin, idealised pictures of women influence our ability to detect digitally altered images? Across 3 experiments (total N=378), female participants viewed an unaltered image, followed by a noise mask, then an image of the same female model that had been modified (in increments of 5%) to be either larger or smaller than the original. Body shape dissatisfaction, ideal body size, Instagram usage, self-esteem and BMI were also measured. In Experiments 1 and 2, participants indicated, via visual analogue scale, perceived change between images (−30% to +30%). In Experiment 3, participants made a same/different judgment, which allowed for psychophysical curve fitting. Participants underestimated change levels for thin models (Experiment 1: t(105)=3.737, p< .001, d=.729; Experiment 2: t(137)=8.474, p< .001, d=1.448), and overestimated change levels for plus-size models (t(137)=6.129, p< .001, d=1.047). Although participants were accurate in determining whether two images of plus-size models were the same or different (t(133)=1.784, p=.077, d=.309), the second image of thin models had to be significantly smaller than the first for participants to report they were the same (t(133)=4.408, p< .001, d=.764). Overall, participants believed photographs had been modified to a lesser degree than they actually had been, particularly for thin models. We suggest that regular exposure to unrealistically thin, idealised images on social media has changed our perception of “normal”, leading to the belief that the average body is larger than it truly is. These findings have implications for our understanding of the roles of social media and social comparisons in relation to body image dissatisfaction.