Sex ratio influences the motivational salience of facial attractiveness

The sex ratio of the local population influences mating-related behaviours in many species. Recent experiments show that male-biased sex ratios increase the amount of financial resources men will invest in potential mates, suggesting that sex ratios influence allocation of mating effort in humans. To investigate this issue further, we tested for effects of cues to the sex ratio of the local population on the motivational salience of attractiveness in own-sex and opposite-sex faces. We did this using an effort-based key-press task, in which the motivational salience of facial attractiveness was assessed in samples of faces in which the ratio of male to female images was manipulated. The motivational salience of attractive opposite-sex, but not own-sex, faces was greater in the own-sex-biased (high competition for mates) than in the opposite-sex-biased (low competition for mates) condition. Moreover, this effect was not modulated by participant sex. These results present new evidence that sex ratio influences human mating-related behaviours. They also present the first evidence that the perceived sex ratio of the local population may modulate allocation of mating effort in women, as well as men

The reward value of infant facial cuteness tracks within-subject changes in women’s salivary testosterone

“Baby schema” refers to infant characteristics, such as facial cues, that positively influence cuteness perceptions and trigger caregiving and protective behaviors in adults. Current models of hormonal regulation of parenting behaviors address how hormones may modulate protective behaviors and nurturance, but not how hormones may modulate responses to infant cuteness. To explore this issue, we investigated possible relationships between the reward value of infant facial cuteness and within-woman changes in testosterone, estradiol, and progesterone levels. Multilevel modeling of these data showed that infant cuteness was more rewarding when women’s salivary testosterone levels were high. Moreover, this within-woman effect of testosterone was independent of the possible effects of estradiol and progesterone and was not simply a consequence of changes in women’s cuteness perceptions. These results suggest that testosterone may modulate differential responses to infant facial cuteness, potentially revealing a new route through which testosterone shapes selective allocation of parental resources

Women's hormone levels modulate the motivational salience of facial attractiveness and sexual dimorphism

The physical attractiveness of faces is positively correlated with both behavioral and neural measures of their motivational salience. Although previous work suggests that hormone levels modulate women's perceptions of others’ facial attractiveness, studies have not yet investigated whether hormone levels also modulate the motivational salience of facial characteristics. To address this issue, we investigated the relationships between within-subject changes in women's salivary hormone levels (estradiol, progesterone, testosterone, and estradiol-to-progesterone ratio) and within-subject changes in the motivational salience of attractiveness and sexual dimorphism in male and female faces. The motivational salience of physically attractive faces in general and feminine female faces, but not masculine male faces, was greater in test sessions where women had high testosterone levels. Additionally, the reward value of sexually dimorphic faces in general and attractive female faces, but not attractive male faces, was greater in test sessions where women had high estradiol-to-progesterone ratios. These results provide the first evidence that the motivational salience of facial attractiveness and sexual dimorphism is modulated by within-woman changes in hormone levels

Women’s facial attractiveness is related to their body mass index, but not their salivary cortisol

Objectives: Although many theories of human facial attractiveness propose positive correlations between facial attractiveness and measures of actual health, evidence for such correlations is somewhat mixed. Here we sought to replicate a recent study reporting that women’s facial attractiveness is independently related to both their adiposity and cortisol. Methods: Ninety-six women provided saliva samples, which were analyzed for cortisol level, and their height and weight, which were used to calculate their body mass index (BMI). A digital face image of each woman was also taken under standardized photographic conditions and rated for attractiveness. Results: There was a significant negative correlation between women’s facial attractiveness and BMI. By contrast, salivary cortisol and facial attractiveness were not significantly correlated. Conclusions: Our results suggest that the types of health information reflected in women's faces include qualities that are indexed by BMI, but do not necessarily include qualities that are indexed by cortisol

Testing the utility of a data-driven approach for assessing BMI from face images

Several lines of evidence suggest that facial cues of adiposity may be important for human social interaction. However, tests for quantifiable cues of body mass index (BMI) in the face have examined only a small number of facial proportions and these proportions were found to have relatively low predictive power. Here we employed a data-driven approach in which statistical models were built using principal components (PCs) derived from objectively defined shape and color characteristics in face images. The predictive power of these models was then compared with models based on previously studied facial proportions (perimeter-to-area ratio, width-to-height ratio, and cheek-to-jaw width). Models based on 2D shape-only PCs, color-only PCs, and 2D shape and color PCs combined each performed significantly and substantially better than models based on one or more of the previously studied facial proportions. A non-linear PC model considering both 2D shape and color PCs was the best predictor of BMI. These results highlight the utility of a “bottom-up”, data-driven approach for assessing BMI from face images

Does the interaction between cortisol and testosterone predict men's facial attractiveness?

Although some researchers have suggested that the interaction between cortisol and testosterone predicts ratings of men’s facial attractiveness, evidence for this pattern of results is equivocal. Consequently, the current study tested for a correlation between men’s facial attractiveness and the interaction between their cortisol and testosterone levels. We also tested for corresponding relationships between the interaction between cortisol and testosterone and ratings of men’s facial health and dominance (perceived traits that are correlated with facial attractiveness in men). We found no evidence that ratings of either facial attractiveness or health were correlated with the interaction between cortisol and testosterone. Some analyses suggested that the interaction between cortisol and testosterone levels may predict ratings of men’s facial dominance, however, with testosterone being more closely related to facial dominance ratings among men with higher cortisol. Our results suggest that the relationship between men’s facial attractiveness and the interaction between cortisol and testosterone is not robust

General sexual desire, but not desire for uncommitted sexual relationships, tracks changes in women's hormonal status

Several recent longitudinal studies have investigated the hormonal correlates of both young adult women's general sexual desire and, more specifically, their desire for uncommitted sexual relationships. Findings across these studies have been mixed, potentially because each study tested only small samples of women (Ns = 43, 33, and 14). Here we report results from a much larger (N = 375) longitudinal study of hormonal correlates of young adult women's general sexual desire and their desire for uncommitted sexual relationships. Our analyses suggest that within-woman changes in general sexual desire are negatively related to progesterone, but are not related to testosterone or cortisol. We observed some positive relationships for estradiol, but these were generally only significant for solitary sexual desire. By contrast with our results for general sexual desire, analyses showed no evidence that changes in women’s desire for uncommitted sexual relationships are related to their hormonal status. Together, these results suggest that changes in hormonal status contribute to changes in women's general sexual desire, but do not influence women's desire for uncommitted sexual relationships

Are physiological and behavioral immune responses negatively correlated? Evidence from hormone-linked differences in men's face preferences

Behaviors that minimize exposure to sources of pathogens can carry opportunity costs. Consequently, how individuals resolve the tradeoff between the benefits and costs of behavioral immune responses should be sensitive to the extent to which they are vulnerable to infectious diseases. However, although it is a strong prediction of this functional flexibility principle, there is little compelling evidence that individuals with stronger physiological immune responses show weaker behavioral immune responses. Here we show that men with the combination of high testosterone and low cortisol levels, a hormonal profile recently found to be associated with particularly strong physiological immune responses, show weaker preferences for color cues associated with carotenoid pigmentation. Since carotenoid cues are thought to index vulnerability to infectious illnesses, our results are consistent with the functional flexibility principle's prediction that individuals with stronger physiological immune responses show weaker behavioral immune responses

Mate choice, mate preference, and biological markets : the relationship between partner choice and health preference is modulated by women's own attractiveness

Although much of the research on human mate preference assumes that mate preference and partner choice will be related to some extent, evidence for correlations between mate preference and mate choice is mixed. Inspired by biological market theories of mate choice, which propose that individuals with greater market value will be better placed to translate their preference into choice, we investigated whether participants' own attractiveness modulated the relationship between their preference and choice. Multilevel modeling showed that experimentally assessed preferences for healthy-looking other-sex faces predicted third-party ratings of partner's facial health better among women whose faces were rated as more attractive by third parties. This pattern of results was not seen for men. These results suggest that the relationship between mate preference and mate choice may be more complex than was assumed in previous research, at least among women. Our results also highlight the utility of biological market theories for understanding the links between mate preference and partner choice

http://wrap.warwick.ac.uk Original citation

Previous research suggests that people who score higher on measures of pathogen disgust demonstrate (1) stronger preferences for healthy individuals when assessing their facial attractiveness and (2) stronger negative attitudes about obese individuals. The relationship between pathogen disgust and attractiveness judgments of faces differing in cues of weight has yet to be investigated, however. Here we found that men's, but not women's, pathogen disgust was positively correlated with their preference for facial cues of lower weight. Moreover, this effect of pathogen disgust was independent of the possible effects of moral and sexual disgust. These data implicate pathogen disgust in individual differences in preferences for facial cues of weight, at least among men, and suggest that the sex-specific effects of pathogen disgust on preferences for facial cues of weight may be different to those previously reported for general negative attitudes about obese individuals