Female health,attractiveness, and desirability for relationships: Role of breast asymmetry and waist-to-hip ratio

Fluctuating asymmetry (FA) of ordinarily bilaterally symmetrical traits in humans has been proposed to indicate developmental anomaly. Recent research has shown that individuals with minimal FA are judged to be attractive, and preferred as sexual partners (Thornhill and Gangestad 1993). Waist-to-hip ratios (WHR) have been also shown to reflect health and reproductive capability of woman and those with low WHRs are judged more attractive and healthy (Singh 1993a,b). The present study examines the relative roles of WHR and FA in female breasts in judgments of female attractiveness, health, and desirability for short-term and long-term relationships. Male college students were asked to judge attractiveness of female figures that differed in WHR (high and low) and breast symmetry (none, low, or high). In the first test, paired comparison method was used in which each figure was paired one at a time with all other figures. In the second test, subjects examined all figures simultaneously, estimated their age, and rated each figure for attractiveness, feminine looks, health, overall degree of body symmetry, and willingness to engage in short- and long-term relationship. Results from both tests show that figures with low WHRs were judged to be more attractive than figures with high WHRs, regardless of their degree of breast asymmetry. The figure with low WHR and symmetrical breasts was judged to be most attractive and youngest of all other figures. It appears that men use both WHR and breast asymmetry in judging attractiveness and being willing to develop romantic relationships. It is proposed that WHR and breast asymmetry may signal different aspects of overall female mate quality.     

Ethnic and gender consensus for the effect of waist-to-hip ratio on judgment of women’s attractiveness

The western consensus is that obese women are considered attractive by Afro-Americans and by many societies from nonwestern developing countries. This belief rests mainly on results of nonstandardized surveys dealing only with body weight and size, ignoring body fat distribution. The anatomical distribution of female body fat as measured by the ratio of waist to hip circumference (WHR) is related to reproductive age, fertility, and risk for various major diseases and thus might play a role in judgment of attractiveness. Previous research (Singh 1993a, 1993b) has shown that in the United States Caucasian men and women judge female figures with feminine WHRs as attractive and healthy. To investigate whether young Indonesian and Afro-American men and women rate such figures similarly, female figures representing three body sizes (underweight, normal weight, and overweight) and four WHRs (two feminine and two masculine) were used. Results show that neither Indonesian nor Afro-American subjects judge overweight figures as attractive and healthy regardless of the size of WHR. They judged normal weight figures with feminine WHRs as most attractive, healthy, and youthful. The consensus on women’s attractiveness among Indonesian, Afro-American, and U.S. Caucasian male and female subjects suggests that various cultural groups have similar criteria for judging the ideal woman’s shape.     

Maternal waist-to-hip ratio does not predict child gender

It has been suggested that a high pre-conceptual waist-to-hip ratio (WHR) is a good predictor of male offspring and, thus, in cultures that value male children, an androgenous body shape may be judged as most attractive. The predictive value of WHRs is based on studies measuring women who already have children and correlating their WHRs with the proportion of existing male offspring. However, carrying a male child may alter WHRs in a different way to carrying a female child, and a high WHR may be an effect rather than a cause of male offspring. In order to test the predictive power of a pre-conceptual WHR and offspring gender, we took WHR measures from 458 women who intended to become pregnant and then correlated this with the genders of their subsequent children. We found no significant correlation. It is therefore not clear why a high WHR is preferred in some cultures. We suggest that differences in attractiveness preferences between different ethic groups are actually based on weight scaled for height (the body mass index or BMI) rather than the WHR since although there will be a preferred optimal BMI for each ethnic group, which will balance environmental and health factors, this optimal BMI may differ between groups and environments.     

Female waist-to-hip ratio,body mass index and sexual attractiveness in China

Men and women at Northwest University (n=751), Xi'an, China were asked to judge the attractiveness of photographs of female patients who had undergone micrograft surgery to reduce their waist-to-hip ratios (WHR). Micrograft surgery involves harvesting adipose tissue from the waist and reshaping the buttocks to produce a low WHR and an 'hourglass' female figure. This gynoid distribution of female body fat has been shown to correlate with measures of fertility and health. Significantly larger numbers of subjects, of both sexes, chose post-operative photographs, with lower WHRs, as more attractive than pre-operative photographs of the same women. Some patients had gained, and some had lost weight, post-operatively, with resultant changes in body mass index (BMI). However, these changes in BMI were not related to judgments of attractiveness. These results show that the hourglass female figure is rated as attractive in China, and that WHR, rather than BMI, plays a crucial role in such attractiveness judgments.     

Male preferences for female waist‐to‐hip ratio and body mass index in the highlands of Papua New Guinea

One hundred men, living in three villages in a remote region of the Eastern Highlands of Papua New Guinea were asked to judge the attractiveness of photographs of women who had undergone micrograft surgery to reduce their waist‐to‐hip ratios (WHRs). Micrograft surgery involves harvesting adipose tissue from the waist and reshaping the buttocks to produce a low WHR and an “hourglass” female figure. Men consistently chose postoperative photographs as being more attractive than preoperative photographs of the same women. Some women gained, and some lost weight, postoperatively, with resultant changes in body mass index (BMI). However, changes in BMI were not related to men's judgments of attractiveness. These results show that the hourglass female figure is rated as attractive by men living in a remote, indigenous community, and that when controlling for BMI, WHR plays a crucial role in their attractiveness judgments. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.     

"You are so beautiful"*: Behind women's attractiveness towards the biology of reproduction: a narrative review

Female beauty has always attracted human beings. In particular, beauty has been interpreted in terms of reproductive potential and advantage in selection of mates. We have reviewed the recent literature on female facial and physical beauty with the objective of defining which parameters could influence female attractiveness. Symmetry, averageness, and sexual dimorphism with regards to facial beauty, as well as waist-to-hip ratio (WHR), breast size, and body mass index (BMI) for physical beauty, have been assessed. In current societies, it appears that facial attractiveness results from a mixture of symmetry and averageness of traits, high forehead and cheekbones, small nose and chin, full lips, thin eyebrows, and thick hair. A low WHR reliably characterized physical attractiveness, whereas inconsistencies have been observed in the evaluation of breast size and BMI. The importance of breast size appears to vary with time and sex of evaluators, whereas the impact of BMI is related to socio-economic conditions. The various hypotheses behind beauty and the role of attractiveness in mate choice and sexual selection are here described in terms of continuation of human species. Intriguing associations are emerging between features of attractiveness and some reproductive disorders, as both are substantially influenced by sex steroid hormones.     

Visual perception of female physical attractiveness

On the basis of visual assessment of figure drawings and front/profile images, past researchers believed that the waist-hip ratio (WHR) and the body mass index (BMI) were two putative cues to female physical attractiveness. However, this view was not tested on three-dimensional (3D) female images. In the present study, 3D images of 31 Caucasian females having varying body weights (BMI ranged from 16 to 35) were shown to 29 male and 25 female viewers, who were asked to rate the physical attractiveness. The results showed that the body volume divided by the square of the height, defined as volume height index (VHI), is the most important and direct visual determinant of female physical attractiveness. In determining the female attractiveness, human observers may first use VHI as a visual cue, which is also a key indicator of health and fertility owing to its strong linear relation to BMI. To fine-tune the judgement, observers may then use body proportions, the most important of which are the ratio of waist height over the chin height (WHC) (a measure of the length of legs over total tallness) and the deviation of WHR from the ideal ratio. It also appears that the effect of the body's physical parameters on the perception of female physical attractiveness conforms to Stevens' power law of psychophysics.     

The role of body fat in female attractiveness

The purpose of the present study was to investigate the role of body fat percentage (BF%) on female attractiveness. To this end, a series of female body images were selected from a collection of dual-energy X-ray absorptiometry scans. Images were stratified by three levels (low, mid, and high) of waist-to-hip ratio (WHR) and seven levels (15%–50%) of BF%. These 21 images were presented in a random order and rated for attractiveness. Results indicate that WHR, BMI, and BF% are all significant predictors of female attractiveness when regressed separately (R²= 0.19, 0.70, and 0.76, respectively). When regressed simultaneously, all three variables accounted for 87% of the variance in image attractiveness, with only BF% and WHR being significant predictors. Further analysis revealed that body fat might disrupt the negative linear relationship between WHR and attractiveness. Men and women differed significantly in most categories of WHR and BF%, with men generally rating images as less attractive than women. These data indicate that BF% appears to be a strong cue for attractiveness and that the impact of WHR and BMI on attractiveness is dependent, in part, on BF%. The appearance of body fat may provide disruption in the visual cues of both shape and size of the female body, potentially impacting behavior.     

Patterns of eye movements when male and female observers judge female attractiveness, body fat and waist-to-hip ratio

Behavioural studies of the perceptual cues for female physical attractiveness have suggested two potentially important features: body fat distribution [the waist-to-hip ratio (WHR)] and overall body fat [often estimated by the body mass index (BMI)]. However, none of these studies tell us directly which regions of the stimulus images inform observers' judgments. Therefore, we recorded the eye movements of three groups of 10 male observers and three groups of 10 female observers, when they rated a set of 46 photographs of female bodies. The first sets of observers rated the images for attractiveness, the second sets rated for body fat and the third sets for WHR. If either WHR and/or body fat is used to judge attractiveness, then observers rating attractiveness should look at those areas of the body which allow assessment of these features, and they should look in the same areas when they are directly asked to estimate WHR and body fat. So we are able to compare the fixation patterns for the explicit judgments with those for attractiveness judgments and infer which features were used for attractiveness. Prior to group analysis of the eye-movement data, the locations of individual eye fixations were transformed into a common reference space to permit comparisons of fixation density at high resolution across all stimuli. This manipulation allowed us to use spatial statistical analysis techniques to show the following: (1) Observers' fixations for attractiveness and body fat clustered in the central and upper abdomen and chest, but not the pelvic or hip areas, consistent with the finding that WHR had little influence over attractiveness judgments. (2) The pattern of fixations for attractiveness ratings was very similar to the fixation patterns for body fat judgments. (3) The fixations for WHR ratings were significantly different from those for attractiveness and body fat.     

Patterns of subcutaneous fat deposition and the relationship between body mass index and waist-to-hip ratio: Implications for models of physical attractiveness

Body mass index (BMI) and waist-to-hip ratio (WHR) are two widely used anthropometric indices of body shape argued to convey different information about health and fertility. Both indices have also been shown to affect attractiveness ratings of female bodies. However, BMI and WHR are naturally positively correlated, complicating studies designed to identify their relative importance in predicting health and attractiveness outcomes. We show that the correlation between BMI and WHR depends on the assumed model of subcutaneous fat deposition. An additive model, whereby fat is added to the waist and hips at a constant rate, predicts a correlation between BMI and WHR because with increasing fat, the difference between the waist and hips becomes smaller relative to total width. This model is supported by longitudinal and cross-sectional data. We parameterised the function relating WHR to BMI for white UK females of reproductive age, and used this function to statistically decompose body shape into two independent components. We show that judgements of the attractiveness of female bodies are well explained by the component of curvaceousness related to BMI but not by residual curvaceousness. Our findings resolve a long-standing dispute in the attractiveness literature by confirming that although WHR appears to be an important predictor of attractiveness, this is largely explained by the direct effect of total body fat on WHR, thus reinforcing the conclusion that total body fat is the primary determinant of female body shape attractiveness.     

BMI not WHR modulates BOLD fMRI responses in a sub-cortical reward network when participants judge the attractiveness of human female bodies

In perceptual terms, the human body is a complex 3d shape which has to be interpreted by the observer to judge its attractiveness. Both body mass and shape have been suggested as strong predictors of female attractiveness. Normally body mass and shape co-vary, and it is difficult to differentiate their separate effects. A recent study suggested that altering body mass does not modulate activity in the reward mechanisms of the brain, but shape does. However, using computer generated female body-shaped greyscale images, based on a Principal Component Analysis of female bodies, we were able to construct images which covary with real female body mass (indexed with BMI) and not with body shape (indexed with WHR), and vice versa. Twelve observers (6 male and 6 female) rated these images for attractiveness during an fMRI study. The attractiveness ratings were correlated with changes in BMI and not WHR. Our primary fMRI results demonstrated that in addition to activation in higher visual areas (such as the extrastriate body area), changing BMI also modulated activity in the caudate nucleus, and other parts of the brain reward system. This shows that BMI, not WHR, modulates reward mechanisms in the brain and we infer that this may have important implications for judgements of ideal body size in eating disordered individuals.     

Body Shape Preferences: Associations with Rater Body Shape and Sociosexuality

There is accumulating evidence of condition-dependent mate choice in many species, that is, individual preferences varying in strength according to the condition of the chooser. In humans, for example, people with more attractive faces/bodies, and who are higher in sociosexuality, exhibit stronger preferences for attractive traits in opposite-sex faces/bodies. However, previous studies have tended to use only relatively simple, isolated measures of rater attractiveness. Here we use 3D body scanning technology to examine associations between strength of rater preferences for attractive traits in opposite-sex bodies, and raters’ body shape, self-perceived attractiveness, and sociosexuality. For 118 raters and 80 stimuli models, we used a 3D scanner to extract body measurements associated with attractiveness (male waist-chest ratio [WCR], female waist-hip ratio [WHR], and volume-height index [VHI] in both sexes) and also measured rater self-perceived attractiveness and sociosexuality. As expected, WHR and VHI were important predictors of female body attractiveness, while WCR and VHI were important predictors of male body attractiveness. Results indicated that male rater sociosexuality scores were positively associated with strength of preference for attractive (low) VHI and attractive (low) WHR in female bodies. Moreover, male rater self-perceived attractiveness was positively associated with strength of preference for low VHI in female bodies. The only evidence of condition-dependent preferences in females was a positive association between attractive VHI in female raters and preferences for attractive (low) WCR in male bodies. No other significant associations were observed in either sex between aspects of rater body shape and strength of preferences for attractive opposite-sex body traits. These results suggest that among male raters, rater self-perceived attractiveness and sociosexuality are important predictors of preference strength for attractive opposite-sex body shapes, and that rater body traits –with the exception of VHI in female raters– may not be good predictors of these preferences in either sex.     

Visual perception of male body attractiveness

Based on 69 scanned Chinese male subjects and 25 Caucasian male subjects, the present study showed that the volume height index (VHI) is the most important visual cue to male body attractiveness of young Chinese viewers among the many body parameters examined in the study. VHI alone can explain ca. 73% of the variance of male body attractiveness ratings. The effect of VHI can be fitted with two half bell-shaped exponential curves with an optimal VHI at 17.6 l m(-2) and 18.0 l m(-2) for female raters and male raters, respectively. In addition to VHI, other body parameters or ratios can have small, but significant effects on male body attractiveness. Body proportions associated with fitness will enhance male body attractiveness. It was also found that there is an optimal waist-to-hip ratio (WHR) at 0.8 and deviations from this optimal WHR reduce male body attractiveness.     

Body shape and women’s attractiveness

This paper examines the role of body fat distribution as measured by waist-to-hip ratio (WHR) on the judgment of women’s physical attractiveness. It presents evidence that WHR is correlated with a woman’s reproductive endocrinological status and long-term health risk. Three studies were conducted to investigate whether humans have perceptual and cognitive mechanisms to utilize the WHR to infer attributes of women’s health, youthfulness, attractiveness, and reproductive capacity. College-age as well as older subjects of both sexes rank female figures with normal weight and low WHR as attractive and assign to them higher reproductive capability. The study concludes that WHR is a reliable and honest signal of a woman’s reproductive potential. The adaptive significance of body fat distribution and its role in mate selection is also discussed.     

Hormonal and morphological predictors of women’s body attractiveness

Does women’s body attractiveness predict indices of reproductive capacity? Prior research has provided evidence that large breast size and low waist-to-hip ratio (WHR) are positively associated with women’s estrogen and progesterone concentrations, but no previous studies appear to have directly tested whether ratings of women's body attractiveness are predicted by higher concentrations of ovarian hormones measured across broad regions of the menstrual cycle. Here, we collected daily saliva samples across 1–2 menstrual cycles from a sample of young women; assayed the samples for estradiol, progesterone, and testosterone; obtained anthropometric measurements of the women’s bodies; and also obtained attractiveness ratings of the women’s bodies from photographs of them taken in standardized clothing with faces obscured. Contrary to previous research, mean hormone concentrations were uncorrelated with breast size and WHR. Body mass index (BMI) was a very strong negative predictor of body attractiveness ratings, similar to previous findings. Zero-order associations between women’s mean hormone concentrations and mean attractiveness ratings were not significant; however, after controlling for BMI, attractiveness ratings were independently and positively associated with both estradiol and testosterone concentrations. Discussion focuses on the implications of these findings for whether attractiveness assessment mechanisms are specialized for the detection of cues of differential fecundity in young women’s bodies.     

Visual cues to female physical attractiveness

Evolutionary psychology suggests that a woman's sexual attractiveness is based on cues of health and reproductive potential. In recent years, research has focused on the ratio of the width of the waist to the width of the hips (the waist-to-hip ratio (WHR). A low WHR (i.e. a curvaceous body) is believed to correspond to the optimal fat distribution for high fertility, and so this shape should be highly attractive. In this paper we present evidence that weight scaled for height (the body mass index (BMI)) is the primary determinant of sexual attractiveness rather than WHR. BMI is also strongly linked to health and reproductive potential. Furthermore, we show how covariation of apparent BMI and WHR in previous studies led to the overestimation of the importance of WHR in the perception of female attractiveness. Finally, we show how visual cues, such as the perimeter-area ratio (PAR), can provide an accurate and reliable index of an individual's BMI and could be used by an observer to differentiate between potential partners.     

The Impact of Psychological Stress on Men's Judgements of Female Body Size

Background

Previous work has suggested that the experience of psychological stress may influence physical attractiveness ideals, but most evidence in favour of this hypothesis remains archival. The objective of this study was to experimentally investigate the impact of stress on men''s judgements of female body size.

Methods

Men were randomly assigned to either an experimental group, in which they took part in a task that heightened stress (experimental group, n = 41) or in which they did not take part in such a task (control group, n = 40). Both groups rated the attractiveness of female bodies varying in size from emaciated to obese, completed a measure of appetite sensation, and had their body mass indices (BMIs) measured.

Results

Between-groups analyses showed that the experimental group was matched with the control group in terms of mean age, BMI, and appetite sensation. Further analyses showed that men in the experimental group rated a significantly heavier female body size as maximally attractive than the control group. Men in the experimental group also rated heavier female bodies as more attractive and idealised a wider range of female figures than did the control group.

Conclusion

This study found that the experience of stress was associated with a preference among men for heavier female body sizes. These results indicate that human attractiveness judgements are sensitive to variations in local ecologies and reflect adaptive strategies for dealing with changing environmental conditions.     

Female mate value at a glance: relationship of waist-to-hip ratio to health,fecundity and attractiveness

A fundamental assumption of adaptive explanations of female attractiveness is that bodily features that males judge as attractive reliably signal youthfulness, healthiness, and fertility or female mate value. One of the bodily features, waist-to-hip ratio (WHR), is a reliable indicator of a female's reproductive age, sex hormone profile, parity and risk for various diseases. Systematic variation in the size of WHR also systematically affects the judgment of female attractiveness, healthiness, and youthfulness. This article summarizes recent findings about the relationship between female's WHR and various factors affecting reproductive capability and risk for diseases. Research on the relationship between attractiveness and WHR is discussed in light of some methodological objections to previous research. Finally, cross-cultural and historical data are presented that suggest that the relationship between WHR and female attractiveness is not culture-specific and not inculcated by modern Western fashion dictates or media.