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Body size and shape seem to have been sexually selected in a variety of species, including humans, but little is known about what attractive bodies signal about underlying genotypic or phenotypic quality. A widely used indicator of phenotypic quality in evolutionary analyses is degree of symmetry (i.e., fluctuating asymmetry, FA) because it is a marker of developmental stability, which is defined as an organism's ability to develop toward an adaptive end-point despite perturbations during its ontogeny. Here we sought to establish whether attractive bodies signal low FA to observers, and, if so, which aspects of attractive bodies are most predictive of lower FA. We used a 3D optical body scanner to measure FA and to isolate size and shape characteristics in a sample of 77 individuals (40 males and 37 females). From the 3D body scan data, 360°videos were created that separated body shape from other aspects of visual appearance (e.g., skin color and facial features). These videos then were presented to 87 evaluators for attractiveness ratings. We found strong negative correlations between FA and bodily attractiveness in both sexes. Further, sextypical body size and shape characteristics were rated as attractive and correlated negatively with FA. Finally, geometric morphometric analysis of joint configurations revealed that sex-typical joint configurations were associated with both perceived attractiveness and lower FA for male but not for female bodies. In sum, body size and shape seem to show evidence of sexual selection and indicate important information about the phenotypic quality of individuals.3D morphometrics ͉ body shape ͉ developmental stability ͉ sexual dimorphism ͉ sexual selection I n humans, as in other species, sex differences in size and shape are attributed to divergent effects of morphology on the survival or reproductive success of each sex (1-10). For human females, smaller waist relative to hips (WHR), larger breasts, and longer legs relative to height have been attributed to fecundity selection and are perceived as attractive by males (8,11,12). In human males, greater height, larger size, and shorter legs relative to height are believed to have arisen through sexual selection by enhancing success in male-male rivalry (6, 7) and by being more attractive to females (6, 12). In addition, pronounced secondary sex characteristics may be preferred because they are signals of a pathogen-resistant genotype (13). However, recent theoretical models suggest that high-quality signalers may be more resistant, equally resistant, or less resistant to pathogens, depending on life history trade-offs between reproductive effort, survival, and fecundity (14, 15). For example, high-quality males that produce costly signals may compromise their future survival but nonetheless be more fit than their low-quality competitors.If sex-typicality of body size and shape are attractive to the opposite sex because they indicate phenotypic quality, then these conspicuous sex-specific signals are expected to correlate negativ...

The recalibrational theory of human anger predicts positive correlations between aggressive 3 formidability and anger levels in males, and between physical attractiveness and anger levels 4 in females. We tested these predictions by using a three dimensional body scanner to collect 5 anthropometric data about male aggressive formidability (measures of upper body 6 muscularity and leg-body ratio) and female bodily attractiveness (waist-hip ratio, body mass 7 index, overall body shape femininity, and several other measures). Predictions were partially 8 supported: in males, two of three anger measures correlated significantly positively with 9 several muscularity measures; in females, self-perceived attractiveness correlated 10 significantly positively with two anger measures. However, most of these significant results 11were observed only after excluding from the sample 27 participants who were older than

Abstract:The final finishing process of advanced ceramic balls used in hybrid precision bearings constitutes two thirds of the total manufacturing cost, hence the effective and economic finishing methods and processes are critical to their widespread application. A novel eccentric lapping machine is designed and manufactured, Hot Isostatically Pressed (HIPed) silicon nitride ball blanks (diameter 13.25 mm) are used to investigate the feasibility of accelerating the ball finishing process while maintaining high surface quality. Taguchi Methods are used during the first step of finishing to optimise lapping parameters, the L9 (3 4 ) Four-Parameter, Three-Level Orthogonal Array is used to design the experiment. Experimental results reveal that this novel eccentric lapping method is very promising, a material removal rate of 40 µm/hour is achievable. The optimum lapping condition is found to be high speed, high load and high paste concentration with 60 µm diamond particles. The analysis of variance (ANOVA) shows that the most significant lapping parameter is lapping load, which accounts for 50% of the total, followed by lapping speed (31%), the particle size and paste concentration parameters only account for 12% and 7% respectively. A comparison with previous lapping experiments and the mechanism of material removal are also discussed briefly.

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.