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

The Breast Size Rating Scale: Development and psychometric evaluation

Existing measures of breast size dissatisfaction have poor ecological validity or have not been fully evaluated in terms of psychometric properties. Here, we report on the development of the Breast Size Rating Scale (BSRS), a novel measure of breast size dissatisfaction consisting of 14 computer-generated images varying in breast size alone. Study 1 (N = 107) supported the scale’s construct validity, insofar as participants were able to correctly order the images in terms of breast size. Study 2 (N = 234) provided evidence of the test-retest reliability of BSRS-derived scores after 3 months. Studies 3 (N = 730) and 4 (N = 234) provided evidence of the convergent validity of BSRS-derived breast size dissatisfaction scores, which were significantly associated with a range of measures of body image. The BSRS provides a useful tool for researchers examining women’s breast size dissatisfaction

The representational capacity of the distributed encoding of information provided by populations of neurons in primate temporal visual cortex

It has been shown that it is possible to read, from the firing rates of just a small population of neurons, the code that is used in the macaque temporal lobe visual cortex to distinguish between different faces being looked at. To analyse the information provided by populations of single neurons in the primate temporal cortical visual areas, the responses of a population of 14 neurons to 20 visual stimuli were analysed in a macaque performing a visual fixation task. The population of neurons analysed responded primarily to faces, and the stimuli utilised were all human and monkey faces. Each neuron had its own response profile to the different members of the stimulus set. The mean response of each neuron to each stimulus in the set was calculated from a fraction of the ten trials of data available for every stimulus. From the remaining data, it was possible to calculate, for any population response vector, the relative likelihoods that it had been elicited by each of the stimuli in the set. By comparison with the stimuli actually shown, the mean percentage correct identification was computed and also the mean information about the stimuli, in bits, that the population of neurons carried on a single trial. When the decoding algorithm used for this calculation approximated an optimal, Bayesian estimate of the relative likelihoods, the percentage correct increased from 14 correct (chance was 5 correct) with one neuron to 67 with 14 neurons. The information conveyed by the population of neurons increased approximately linearly from 0.33 bits with one neuron to 2.77 bits with 14 neurons. This leads to the important conclusion that the number of stimuli that can be encoded by a population of neurons in this part of the visual system increases approximately exponentially as the number of cells in the sample increases (in that the log of the number of stimuli increases almost linearly). This is in contrast to a local encoding scheme (of 'grandmother' cells), in which the number of stimuli encoded increases linearly with the number of cells in the sample. Thus one of the potentially important properties of distributed representations, an exponential increase in the number of stimuli that can be represented, has been demonstrated in the brain with this population of neurons. When the algorithm used for estimating stimulus likelihood was as simple as could be easily implemented by neurons receiving the population's output (based on just the dot product between the population response vector and each mean response vector), it was still found that the 14-neuron population produced 66 correct guesses and conveyed 2.30 bits of information, or 83 of the information that could be extracted with the nearly optimal procedure. It was also shown that, although there was some redundancy in the representation (with each neuron contributing to the information carried by the whole population 60 of the information it carried alone, rather than 100), this is due to the fact that the number of stimuli in the set was limited (it was 20). The data are consistent with minimal redundancy for sufficiently large and diverse sets of stimuli. The implication for brain connectivity of the distributed encoding scheme, which was demonstrated here in the case of faces, is that a neuron can receive a great deal of information about what is encoded by a large population of neurons if it is able to receive its inputs from a random subset of these neurons, even of limited numbers (e.g. hundreds)

Are attitudinal and perceptual body image the same or different? Evidence from high-level adaptation

We used a high-level adaptation paradigm to distinguish between two hypotheses: i) perceptual and attitudinal body image measurements reflect conceptually different mechanisms which are statistically independent of each other; ii) attitudinal (e.g., questionnaire) and perceptual (e.g., visual yes-no) body image tasks represent two different ways of measuring exactly the same construct. Forty women, with no history of eating disorders, carried out the experiment. Each participant carried out five adaptation blocks, with adapting stimuli representing female bodies at: extreme-low body mass index (BMI), mid-low BMI, actual BMI of the observer, mid-high BMI and extreme-high BMI. Block order was randomized across participants. The main outcome variable was percentage error in participants’ self-estimates of body size, measured post-adaption. In regressions of this percentage error on the strength of the adapting stimuli together with observers’ attitudinal body image as a covariate, we found positive regression slopes and no evidence for any interaction between the fixed effects. Therefore, we conclude that perceptual and attitudinal body image mechanisms are indeed independent of each other. In the light of this evidence, we discuss how people with eating disorders, like anorexia nervosa, may come to over-estimate their body size

The muscular male: a comparison of the physical attractiveness preferences of gay and heterosexual men

This study examined the association between sexual orientation and the perception of men's physical attractiveness. Twenty-seven heterosexual men and 23 gay men were asked to rate, according to physical attractiveness, a series of images of real men with known body mass index (BMI) and waist-to-chest ratio (WCR). The results showed that the WCR was the primary component of attractiveness ratings for both heterosexual and gay men. However, gay men showed a stronger preference for lower WCRs, indicating a preference for a more developed upper-body build. There were small differences in terms of preference for overall body weight, with both groups preferring an image with a BMI of about 21kg/m2. The findings are discussed in terms of gay culture, which emphasises the importance of muscularity in physical attraction

A comparison of actual-ideal weight discrepancy, body appreciation, and media influence between street-dancers and non-dancers

Previous work on body image has tended to treat dancers as a relatively homogenous group, despite the existence of different dance styles and genres. In the current study, we examined body image among individuals involved in street-dancing (genres that typically evolved outside formal settings and are often improvisational in nature) and an age-matched comparison of non-dancers. A total of 83 street-dancers and 84 non-dancers completed scales measuring their actual-ideal weight discrepancy, body appreciation, sociocultural attitudes toward appearance, and demographics. Controlling for participant body mass index (BMI), results showed no significant between-group difference in actual-ideal weight discrepancy, although street-dancers had significantly higher body appreciation than non-dancers. In addition, media influences were implicated in body image concepts for both groups, although internalisation of athletic ideals was more important for street-dancers. These results are discussed in relation to the extant research on body image among dancers

Perceptions of female body weight and shape among indigenous and urban Europeans

Two important cues to female physical attractiveness are body mass index (BMI) and body shape as measured by the waist-to-hip ratio (WHR). This study examined the relative contribution of both cues in three culturally distinct populations. A total of 119 Finnish, Sámi and British male observers rated a set of un-edited photographs of women with known BMI and WHR. The results showed that there were significant differences in preferences for physical attractiveness, with the indigenous Sámi preferring figures with larger BMIs and more tolerant of heavyweight figures than either Finnish participants in Helsinki or Britons in London, who were indistinguishable in their preferences for slim figures. The findings are discussed in terms of evolutionary psychological explanations of mate selection, and sociocultural theories which emphasizes the learning of preferences for body sizes in social and cultural contexts

The relative contribution of profile body shape and weight to judgements of women's physical attractiveness in Britain and Malaysia

Ninety-six Malaysian and British men rated for physical attractiveness a set of photographs of real women in profile, with known body mass index (BMI) and waist-to-hip ratio (WHR). Results showed that BMI accounted for the greater amount of variance in all settings. There were also significant differences in preferences for body weight, with low resource, low socioeconomic status (SES) raters preferring a significantly heavier partner than high resource, high SES raters. The disparity with previous findings using line drawings of women in profile was discussed in terms of the weaknesses of line-drawn stimuli

An examination of ethnic differences in actual-ideal body weight discrepancy and its correlates in a sample of Malaysian women

The present study examined ethnic differences in actual-ideal body weight discrepancy and its correlates among a sample of Malaysian adult women. A total of 459 Malays, 307 Chinese and 150 Indians from Kuala Lumpur completed measures of their actual-ideal body weight discrepancy, sociocultural messages about appearance, self-reported body mass index (BMI) and demographics. Results showed that Chinese women had smaller actual-ideal body weight discrepancy scores than both Malay and Indian women, although the effect size of this difference was small ( =.01). There were also significant ethnic differences in the internalisation of media messages about appearance, although effect sizes were likewise small. Further analyses revealed that sociocultural messages about appearance and self-reported BMI explained between 28% and 47% of the variance in actual-ideal body weight discrepancy for the three ethnic groups, respectively. These results are discussed in relation to the extant literature on body image in the Malaysian context

A comparison of body size ideals, body dissatisfaction, and media influence between female track athletes, martial artists, and non-athletes

Objectives - In assessments of body image among athletes, there remains an important discrepancy between studies reporting, on one hand, increased body dissatisfaction among athletes and, on the other, lower body image concerns. In order to help resolve this contradiction, the present study examined body size ideals, body dissatisfaction, and media influence among female recreational athletes and non-athletes. Method - Forty-one track athletes (a judged sport in which leanness is actively promoted), 47 women involved in Taek Won Do (a martial art with little or no emphasis on leanness), and 44 non-athletes completed self-report measures of ideal body size, body dissatisfaction, and media influence, and provided their demographic details. Results - Results showed that, after controlling for participants' body mass index (BMI), there were no significant between-group differences in ideal body size. By contrast, track athletes reported the highest body dissatisfaction scores and the highest internalisation of athletic media messages. Results of a regression analysis showed that, for the total sample, participants' BMI and internalisation of athletic media messages predicted body dissatisfaction over-and-above involvement in the different sports. Conclusion - These results support the suggestion that women participating in leanness-promoting sports experience greater body dissatisfaction than women in other sports or non-athletes