سطح هورمون زنانه برجستگی انگیزشی از جذابیت صورت و تفاوت جنسی را تعدیل می کند

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.

Facial attractiveness is a particularly salient social cue that influences many important social outcomes. For example, people prefer to mate with, date, associate with, hire, and vote for attractive individuals (see Langlois et al., 2000 for a meta-analytic review). Several lines of evidence also demonstrate that physically attractive faces have motivational salience. For example, the extent to which people will key press to increase the length of time for which they can view faces is correlated with the physical attractiveness of the faces (Aharon et al., 2001, Levy et al., 2008 and Hahn et al., 2013). Additionally, compared to viewing physically unattractive faces, viewing physically attractive faces elicits greater activation in brain regions implicated in motivation and the processing of rewards, such as the nucleus accumbens and medial orbitofrontal cortex (see Bzdok et al., 2011 and Mende-Siedlecki et al., 2013 for meta-analytic reviews). Moreover, behavioral measures of motivational salience predict neural measures of faces’ reward value better than do perceptions of attractiveness measured by ratings (Aharon et al., 2001). Several lines of evidence suggest that changes in women's hormone levels during the menstrual cycle may affect their perceptions of others’ facial attractiveness (see Gildersleeve et al., 2014 for a meta-analytic review). For example, studies have reported that women's preferences for masculine men are positively correlated with their estradiol (e.g., Roney and Simmons, 2008 and Roney et al., 2011) or testosterone (e.g., Welling et al., 2007 and Bobst et al., 2014) levels. By contrast with the relatively large number of studies investigating how women's perceptions of others’ attractiveness covary with changes in women's hormone levels, no previous studies have tested for effects of women's hormone levels on the motivational salience of facial attractiveness. This is surprising, given the importance of attractiveness for social interaction ( Langlois et al., 2000) and research suggesting that women's testosterone ( Hermans et al., 2010) or estradiol ( Dreher et al., 2007) modulates the extent to which financial incentives activate brain regions involved in motivation and the processing of reward. In light of the above, we investigated the hormonal correlates of within-woman changes in the motivational salience of male and female facial attractiveness. Women (none of whom were using any form of hormonal supplement, such as hormonal contraceptives) were each tested once a week for five weeks (i.e., each woman completed five weekly test sessions). In each of these test sessions, the motivational salience of male and female facial attractiveness was assessed and a saliva sample was collected. The motivational salience of faces was measured using a standard key-press task that has previously been shown to be a particularly good predictor of neural measures of the reward value of faces (Aharon et al., 2001). Saliva samples were analyzed for estradiol, progesterone, and testosterone levels. Many previous studies of hormone-mediated responses to faces have emphasized the potential importance of sexually dimorphic facial characteristics, particularly in men's faces (reviewed in Gildersleeve et al., 2014). Since the relationship between men's facial attractiveness and sexual dimorphism is complex (reviewed in Roney et al., 2011), with many studies finding no correlation between sexual dimorphism and attractiveness, we also tested for possible effects of hormone levels on the motivational salience of sexual dimorphism in faces. Given that sexual dimorphism and attractiveness are more reliably and highly correlated in female than male faces (see Rhodes, 2006 for a meta-analytic review), the effects of hormone levels on responses to attractiveness and sexual dimorphism in female faces may be more similar than the corresponding effects for male faces.