Variations in women’s waist to hip ratio and breast size correspond with variations in brain activity, according to research published in Evolution and Human Behavior that examined neurophysiological responses to computer-generated female body silhouettes.
“When you see someone and find them attractive, your visual system has taken in the cues from that person’s face, body shape, facial expression, posture, and so on. These cues are processed in different regions of your brain,” explained study author Farid Pazhoohi, a psychologist based at the University of British Columbia.
“While previous research has looked at how and where facial attractiveness is being processed in the brain, the field lacks empirical research as to how the attractiveness of the body is perceived and processed by the brain. This study aimed to provide evidence regarding this matter.”
In the study, 48 heterosexual men and women, who ranged in age from 18 to 37 years old, viewed black and white silhouettes of female figures with various waist to hip ratios and breast sizes. They were instructed to view the images on a computer screen and press the “M” key whenever they saw a shawl around the waist of the silhouette. The participants were then asked to provide attractiveness ratings for each of the images.
During these tasks, the researchers used an electroencephalogram to record each participant’s electrical brain activity.
In line with previous research, both men and women rated silhouettes with large breasts as more attractive than those with small breast sizes, and they rated waist to hip ratios of 0.6 and 0.7 as more attractive than a waist to hip ratio of 0.8.
The researchers also found evidence that the more attractive silhouettes were processed differently than the less attractive silhouettes.
“Here we show that the human brain is able to perceive and process such bodily features and their differences as quickly as 200 milliseconds (one fifth of one second). And these brain responses are not affected by task requirement, meaning we found that before participants are asked about the attractiveness of the stimuli, their brains still respond differently to attractive body morphs. We also estimated that these responses are originating from brain regions associated with reward processing and decision-making,” Pazhoohi told PsyPost.
In particular, variations in waist to hip ratio appeared to influence activity in frontal brain regions, such as the anterior cingulate and orbitofrontal cortex, while variations in breast size appeared to influence activity in posterior parietal regions, such as the fusiform gyrus, precentral gyrus, and precuneus.
But there is still much to learn about how the brain processes physical attractiveness. “The research on neuropsychology of bodily attractiveness perception is in its early stages. For example, understanding brain responses to bodily postures, or the neurophysiology of men’s physical attractiveness, are just two basic questions that remain to be investigated,” Pazhoohi explained.
“Moreover, the findings from our study also need to be replicated and extended, as we only used two different breast sizes, and three waist to hip ratios, and we know there is a huge diversity of body shape and sizes.”
“These are very early days in this area of research. Questions regarding how culture, gender, age, affect perceptions of physical attractiveness, and the brain mechanisms that support those perceptions, remain to be explored. In addition, how these findings relate to real-world perceptions, decisions, and behaviours, need to be examined. In sum, very exciting days lie ahead!” Pazhoohi said.
The study, “Waist to hip ratio and breast size modulate the processing of female body silhouettes: An EEG study“, was authored by Farid Pazhoohi, Joana Arantes, Alan Kingstone, and Diego Pinal.