Microbes and masculinity: Does exposure to pathogenic cues alter women's preferences for male facial masculinity and beardedness?

Women’s preferences for men’s androgen dependent secondary sexual traits are proposed to be phenotypically plastic in response to exposure to pathogens and pathogen disgust. While previous studies report that masculinity in facial shape is more attractive to women who have recently been exposed to pathogenic cues and who are high in self-reported pathogen disgust, facial hair may reduce male attractiveness under conditions of high pathogens as beards are a possible breeding ground for disease carrying ectoparasites. In the present study, we test whether women’s preferences for beardedness and facial masculinity vary due to exposure to different pathogenic cues. Participants (N = 688, mean age + 1SD = 31.94 years, SD = 6.69, range = 18–67) rated the attractiveness of facial composite stimuli of men when they were clean-shaven or fully bearded. These stimuli were also manipulated in order to vary sexual dimorphism by ±50%. Ratings were conducted before and after exposure to one of four experimental treatments in which participants were primed to either high pathogens (e.g. infected cuts), ectoparasites (e.g. body lice), a mixture of pathogens and ectoparasites, or a control condition (e.g. innocuous liquids). Participants then completed the three-domain disgust scale measuring attitudes to moral, sexual and pathogen disgust. We predicted that women would prefer facial masculinity following exposure to pathogenic cues, but would show reduced preferences for facial hair following exposure to ectoparasites. Women preferred full beards over clean-shaven faces and masculinised over feminised faces. However, none of the experimental treatments influenced the direction of preferences for facial masculinity or beardedness. We also found no association between women’s self-reported pathogen disgust and their preferences for facial masculinity. However, there was a weak positive association between moral disgust scores and preferences for facial masculinity, which might reflect conservatism and preferences for gender typicality in faces. Women’s preferences for beards were positively associated with their pathogen disgust, which runs contrary to our predictions and may reflect preferences for high quality individuals who can withstand any costs of beardedness, although further replications are necessary before firm conclusions can be made. We conclude that there is little support for pathogenic exposure being a mechanism that underpins women’s directional preferences for masculine traits

Mating strategies and the masculinity paradox: How relationship context, relationship status, and sociosexuality shape women's preferences for facial masculinity and beardedness

According to the dual mating strategy model, in short-term mating contexts women should forego paternal investment qualities in favor of mates with well-developed secondary sexual characteristics and dominant behavioral displays. We tested whether this model explains variation in women’s preferences for facial masculinity and beardedness in male faces. Computer-generated composites that had been morphed to appear +/-50% masculine were rated by 671 heterosexual women (M age = 31.72 years, SD = 6.43) for attractiveness when considering them as a short-term partner, long-term partner, a co-parent or a friend. They then completed the Revised Sociosexual Inventory (SOI-R) to determine their sexual openness on dimensions of desire, behavior, and attitudes. Results showed that women’s preferences were strongest for average facial masculinity, followed by masculinized faces, with feminized faces being least attractive. In contrast to past research, facial masculinity preferences were stronger when judging for co-parenting partners than for short-term mates. Facial masculinity preferences were also positively associated with behavioral SOI, negatively with desire, and were unrelated to global or attitudinal SOI. Women gave higher ratings for full beards than clean-shaven faces. Preferences for beards were higher for co-parenting and long-term relationships than short-term relationships, although these differences were not statistically significant. Preferences for facial hair were positively associated with global and attitudinal SOI, but were unrelated to behavioral SOI and desire. Although further replication is necessary, our findings indicate that sexual openness is associated with women’s preferences for men’s facial hair and suggest variation in the association between sociosexuality and women’s facial masculinity preferences

Toward understanding and exploiting tumor heterogeneity

The extent of tumor heterogeneity is an emerging theme that researchers are only beginning to understand. How genetic and epigenetic heterogeneity affects tumor evolution and clinical progression is unknown. The precise nature of the environmental factors that influence this heterogeneity is also yet to be characterized. Nature Medicine, Nature Biotechnology and the Volkswagen Foundation organized a meeting focused on identifying the obstacles that need to be overcome to advance translational research in and tumor heterogeneity. Once these key questions were established, the attendees devised potential solutions. Their ideas are presented here

The fixed effects coefficients (and standard errors) and associated 95% confidence intervals for the influence of moral disgust, sexual disgust, pathogen disgust, as well as sexual dimorphism and beardedness on attractiveness ratings.

<p>The fixed effects coefficients (and standard errors) and associated 95% confidence intervals for the influence of moral disgust, sexual disgust, pathogen disgust, as well as sexual dimorphism and beardedness on attractiveness ratings.</p

The role of facial masculinity and beardedness in women’s judgments of men’s attractiveness.

<p>Data are the mean attractiveness ratings (± 1 SEM) of feminized and masculinized face, split by clean-shaven (open bars) and fully bearded faces (grey bars). *** = p < 0.001. The images at the top of the figure are computer-generated and do not represent the true identities of any individual.</p

The effect of treatment on women’s preferences for men’s facial masculinity.

<p>Data are the mean attractiveness ratings (± 1 SEM) of feminised (open bars) and masculinised faces (grey bars) for judgments pre and post exposure to ectoparasites (<b>A.</b>), pathogens (<b>B.</b>), mixed (<b>C.</b>) and control (<b>D.</b>) treatments. N.S = Not statistically significant.</p

The associations between the three domains of disgust and women’s preferences for men’s facial masculinity and beardedness.

<p>Data show the effects of low (-1SD) and high (+1SD) pathogen (A.), sexual (B.), and moral (C.) disgust sensitivity on women’s preference for facial masculinity (left) and facial masculinity (right). *** = 95% confidence interval does not contain 0, indicating statistical significance. N.S = Not statistically significant.</p

Repeated-measures ANOVA testing the effect of beardedness (clean-shaven, full beard), masculinity (+50%, -50%), time (pre, post) and pathogen treatment (ectoparasites, pathogens, mixed, and control) on women’s attractiveness ratings of male faces.

<p>Repeated-measures ANOVA testing the effect of beardedness (clean-shaven, full beard), masculinity (+50%, -50%), time (pre, post) and pathogen treatment (ectoparasites, pathogens, mixed, and control) on women’s attractiveness ratings of male faces.</p

Examples of the male stimuli used in this study.

<p>Images depict composites of the same five individuals with full beards (upper images) and when clean-shaven (lower images), as well as when manipulated to appear 50% more masculinized (right images) or 50% less masculinized (i.e. feminized; left images). These images are computer-generated and do not represent the true identities of any individual.</p

The effect of treatment on women’s preferences for men’s beardedness.

<p>Data are the mean attractiveness ratings (± 1 SEM) of clean-shaven (open bars) and fully bearded faces (grey bars) pre and post exposure to ectoparasites (<b>A.</b>), pathogens (<b>B.</b>), mixed (<b>C.</b>) and control (<b>D.</b>) treatments. N.S = Not statistically significant.</p