The thighs have it: evidence for the importance of lower body regions in female body size judgments.

backgroundThis study investigated the body features underpinning accurate size judgments of female bodies, and whether judgment accuracy varies with body size. Previous research indicates several body features can influence size judgments; however, there is uncertainty around which specific parts are important, if those vary with size, and whether body perception involves holistic processing (i.e., the whole body) or relies on specific cues (i.e., certain body parts). To examine these questions, we used the bodyline task, which measures two underlying sources of perceptual error in body size judgments: regression to the mean and serial dependence.

resultsIn Experiment 1 (N = 99), we compared judgments of whole bodies to those made viewing the top-half or bottom-half only. Viewing the bottom-half only produced judgments as accurate as those for the whole body, suggesting holistic processing of the whole body is not required for body size judgments. Experiment 2 (N = 116) built on that result by comparing judgments when only the inner or outer thigh region were visible, compared to the whole body. Both isolated thigh regions led to significantly poorer accuracy in judgments compared to whole-body stimuli, indicating that accurate size judgments require more body features than those alone.

conclusionsOur findings demonstrate that accurate judgment of female body size does not require holistic processing but does involve integration of multiple features within the lower body region. These results have implications for understanding the perceptual processes involved in body size estimation with potential for broader considerations of body image disorders.