Facial masculinity

Facial masculinity refers to masculine facial features such as narrower eyes, a broader mandible, chin, forehead and nose, broader (but not necessarily more protruding) cheekbones,https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2022.0211 elongated lower face height below the nasal region, a more protruded and more robust brow ridge, facial hair, a darker complexion, and the overall maturity and robustness of the face.https://www.sciencedirect.com/science/article/abs/pii/S0018442X15000943
==In-depth explanation==
Facial masculinity appears primarily determined by the level of pre-natal testosterone exposure. A second spurt of testosterone during puberty also plays a role in masculinizing men's faces.https://royalsocietypublishing.org/doi/full/10.1098/rspb.2011.2351https://www.sciencedirect.com/science/article/abs/pii/S0018506X11002157
Although facial masculinity is commonly referred to in the incelosphere (especially among the blackpilled subset of that community) and elsewhere as a significant element of male looks, facial masculinity seems to be unrelated to male's facial attractiveness as rated by women when perceived height is controlled.https://www.nature.com/articles/s41598-021-85402-3.pdf
Therefore, studies that find that women prefer more facially masculine men are often confounded by the fact that both perceived and actual facial masculinity scales with height and body size,https://pubmed.ncbi.nlm.nih.gov/25638935/and thus women's preference for taller and perhaps also bulkier men likely drives some of this effect.
Other studies into this topic often show no effects or even an effect in the direction of more feminized male faces being preferred by women.https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0225549#pone.0225549.ref040
More ecologically valid studies examining the effects of male facial masculinity on female-evaluated male desirability find that objectively measured facial sexual dimorphism in males does promote higher attractiveness ratings for men. But this effect is non-significant among men when ethnicity is controlled for, suggesting that ethnic differences in levels of facial masculinity and preference for such may have skewed previous findings that only examined caucasians.https://www.sciencedirect.com/science/article/abs/pii/S109051382300051X p. 8 This study also found no evidence of assortative mating for facial masculinity,ibid which was supported by earlier findings that also presented a null result for relational assortment (positive and negative) in facial masculinity.https://pubmed.ncbi.nlm.nih.gov/21343440/
However, these mixed findings may not apply to the extremes and when considering cross-ethnic differences in average levels and preferences for the level of facial masculinity in a potential dating partner.
The link between facial masculinity and overall sexual and reproductive success also seems generally non-existent in modern societies. A meta-analysis of the relationship between various forms of observable masculinity found no significant relationship between facial masculinity and sexual success or the number of children fathered in modern developed societies.https://www.biorxiv.org/content/10.1101/2020.03.06.980896v1/ The lack of strong effects found for morphological facial masculinity despite people's incessant insistence that women are strongly drawn to facially masculine men may also be explained by the fact that rated facial masculinity only correlates weakly with objective facial masculinity (r = 0.3). It is possible that perceptions of masculinity are generally associated with desirable traits such as physical attractiveness in a sort of halo effect, but many of the desirable men that are perceived as masculine often do not have particularly sexually dimorphic faces when this is measured in more objective terms of the geometric landmarks of the face that tend to diverge between the sexes.https://pubmed.ncbi.nlm.nih.gov/15252993/
The extent to which a man's facial masculinity is desired by women or associated with dating outcomes is affected by contextual and ecological factors.
Specifically, research has indicated that individual characteristics such as a woman's mating strategy together with the woman's self-perceived mate value generally alter a woman's preference for the level of sexual dimorphism in a male partner's face. Environmental factors such as income inequality and harshness also seem to affect women's preferences for facial masculinity, with resource-abundant ecologies and higher levels of social inequality being associated with a more pronounced female preference for sexually dimorphic traits in male faces, at least in forced-choice tasks (choosing between masculinized and feminized faces.)https://www.nature.com/articles/s41598-021-90473-3#Sec8
==Evolution of facial masculinity==
Facial masculinity may have evolved to aid men in competing with and intimidating other men to gain access to females and resources in certain contexts. It enhances perceptions of aggressiveness and dominance.https://link.springer.com/article/10.1007%2Fs40750-020-00128-2 Partnered men generally perceive more facially masculine rivals as representing a greater threat to the stability of their relationships.
https://www.sciencedirect.com/science/article/abs/pii/S0191886911004910 If such links between physical intimidation and mating success in men exist, though, they seem largely limited to bodily cues of physical strength and size rather than facial structure, also suggesting higher historical levels of selection pressure on these traits.https://incels.wiki/w/Scientific_Blackpill#Among_male_university_students.2C_only_cues_of_physical_dominance_over_other_men_predicted_their_mating_success
Facial masculinity is also associated with the overall size and robustness of the skull.https://www.researchgate.net/publication/262941134_Face_of_a_fighter_Bizygomatic_width_as_a_cue_of_formidability Some of these masculine features may have developed due to historical natural selection pressure on these features among men.https://onlinelibrary.wiley.com/doi/abs/10.1111/brv.12112 In other words, high rates of violence in humanity's past may have selected for men with these traits. These men may have been more likely to survive violent incidents and pass on their genes. Ancestral men may have been historically at greater risk of dying from contact violence than women, as is found among certain highly-violent contemporary hunter-gatherer societies.https://www.pnas.org/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEyOiIyMzkvNDg0My85ODUiO3M6NDoiYXRvbSI7czoyMjoiL3BuYXMvMTA2LzIwLzgxMzQuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9https://books.google.com/books/about/Ethnographic_Essays_in_Cultural_Anthropo.html?id=r-cUAgAACAAJ In modern societies, men also make up the majority of homicide victims worldwide.http://www.unodc.org/documents/gsh/pdfs/2014_GLOBAL_HOMICIDE_BOOK_web.pdf
This is further supported the fact that even contentious and imperfect measures of facial robustness, such as facial width to height ratio, positively predict fighting success, even when controlling for body size thought facial robustness is positively associated with body size also.https://onlinelibrary.wiley.com/doi/full/10.1002/ab.22027
Thus, it is possible that facial masculinity served a more direct adaptive survival boosting function and/or an intersexual competition ability signalling function rather than an ornamental signalling (handicap hypothesis) related function throughout much of human history, which would explain why studies examining female attraction to facial masculinity produce inconsistent results, together with the existence of potential female mating tradeoffs between perceived threat and perceived social dominance/protection ability.
It is important to note, however that it is often difficult to disentangle sexually selected mediated intrasexual completion and direct survival benefits and this processes are linked. For example, physical violence has historically been, and still is, a form of intrasexual competition among men itself. Thus, it is certainly possible that facial masculinity serves a dual function here. Some evidence that supports the idea that intrasexual competition pressure selects for facial masculinity, whether mediated directly or indirectly by violence, is that African pastoralists are generally more facially masculine than farmers.https://www.researchsquare.com/article/rs-2802336/v1 These sorts of societies tend to be more violent than settled oneshttps://www.oecd-ilibrary.org/development/pastoralist-violence-in-north-and-west-africa_63dff519-en and tend to culturally co-evolve following polygynous marriage institutions.https://academic.oup.com/beheco/article/30/6/1567/5529775 Therefore, it is likely that violent societies where competition for female partners and the resources and esteem needed to obtain them are heightened select more for facial masculinity. This selection for facial masculinity could be mediated either by selection for intimidation or viability, or likely both.
==Partner investment-related trade-offs==
Part of the reason there appears to be no significant group-level associations between greater levels of facial masculinity and sexual and reproductive success is because there seems to be substantial variation in women's preferences for masculine faces. This variation appears to depend on a large variety of individual, societal and sociosexual factors, such as short-term vs. long-term mating context, personal preferences, and the resource abundance or scarcity of their environments.
The most common explanation for this is based on evolutionary psychology hypotheses that claim there exists a trade-off between investment potential when women are evaluating male partners and so-called 'good genes' benefits.
This hypothesis predicts that among more promiscuous women, and in short-term mating contexts, women will have a general preference for more masculine male faces. In long-term relationships, women will prefer more feminine looks, as masculine men are said to be both higher in sexual value and more likely to cheat on their partners.
There is some supporting evidence for the theory in that women are using facial masculinity as an indicator of their male partner's investment potential. There is some evidence that men's facial masculinity is indeed a valid cue of males' investment potential. Research has found that more masculine faces men are slightly more likely to engage in infidelity and mate poaching behaviors. However, this is barely detectable above chance, and facial masculinity is thus only a weak heuristic of men's faithfulness.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6502397/
Furthermore, if facial masculinity is generally attractive to women, but they sometimes select against it as it denotes that the man will be unlikely to invest in then, then more attractive women would be expected to be the most attracted to facially masculine men, because these women would both have higher standards and would be expected to attract more investment from males in general.
A meta-analysis of the relationship between own-attractiveness and preferences for sexually dimorphic traits in the opposite sex published in the journal Frontiers in Psychology (Chen et al., 2018) does provide some evidence for the trade-off hypothesis. This meta-analysis found that more attractive women seem to prefer more facially masculine men.
However, it is essential to note that this study conflated self-reported and observer-rated and other more objective measures of physical attractiveness. Further research has demonstrated a link only between female's conceptions of their attractiveness and their preferences for facially masculine males, not their objective attractiveness.https://www.sciencedirect.com/science/article/abs/pii/S1090513820300611
The authors found the positive association between higher levels of female attractiveness and preference for facial masculinity was weaker than these women's greater preference for masculine voices and bodies.https://pubmed.ncbi.nlm.nih.gov/30568615/
Buss & Shackleford (2008) did discover a weak positive correlation between a woman's third-party rated facial and body attractiveness and her preference for "masculinity." However, it was not specified if it was objectively sexually dimorphic male facial traits these women were desiring.https://journals.sagepub.com/doi/10.1177/147470490800600116
As it stands, if facial masculinity is taken as a significant signal of 'good genes' in itself, the trade-off theory seems to be on shaky ground in terms of empirical evidence, having only feeble evidence supporting it. 
Other research has cast some doubt on the investment trade-off hypothesis, as while male facial attractiveness predicted women's views of their potential to directly invest in their children with paternal care, facial masculinity did not.https://psyarxiv.com/7pj8w/ However, the potential for trade-offs still exists in terms of preferences for perceived dominance vs. care (for the woman) and the woman's tolerance for the man's level of direct physical threat.
Another study that may contradict the idea that more attractive women prefer more facially masculine men as they are confident in their ability to receive investment from them was presented by Welling et al. (2008), as they found that the relationship between female self-rated attractiveness and their masculinity preference was entirely mediated by their levels of extraversion.https://www.sciencedirect.com/science/article/abs/pii/S0191886909003055 As extraversion is associated with impulsivity and stimulus seeking, this may indicate that they prefer more masculine men because they are more short-term mating minded, and not because they believe they will receive investment due to their superior looks.
Studies generally find much stronger effects for masculinized bodies compared to faceshttps://link.springer.com/article/10.1007%2Fs10508-006-9029-3https://pubmed.ncbi.nlm.nih.gov/30568615/ and most that do see effects are focused on determining women's preferences when they are at their fertile peak during ovulation, only typically finding effects for hypothetical short-term mating contexts.https://www.sciencedirect.com/science/article/abs/pii/S109051380500019Xhttps://www.sciencedirect.com/science/article/abs/pii/S0306453011003374
However, this whole line of research into women's preferences in terms of masculinity of men's bodies and faces changing during their menstrual cycle has recently fallen under intense criticism from elements of the academic community, as will be discussed below.
==Ovulatory shift hypothesis and dual mating==
The ideal of female trade-offs related to receiving 'good genes' from masculine men and investment from less masculine men is related to the controversial ovulatory shift hypothesis. This hypothesis states that women's preferences for overall masculinity and other 'good genes' related traits in potential partners increase over their ovulatory cycle as they begin to ovulate), resulting in females adopting a strategy of dual mating. 
It follows from this that it may be evolutionarily advantageous for women to select agreeable and provident partners for long-term relationships to receive investment in their offspring. Since men that have both "good genes" and those personality traits would be in short supply, it follows that it may benefit women to opportunistically cuckold these highly supportive but "genetically inferior" partners by sleeping with more masculine men with "good genes" when they are fertile.
Masculine-faced men are claimed to have "good genes" as, in many animal species, testosterone is immunosuppressive, and thus being able to develop testosterone-derived traits can function as an honest signal of a robust immune system.
Thus, if women successfully pull off this strategy, they 'get their cake and eat it too', as they get investment from the beta and genes from the alpha. Not surprisingly, this hypothesis is quite popular in the redpill and blackpill communities, where it is commonly known as alphafuxx/betabuxx.
However, research that has attempted to produce evidence of women experiencing such ovulatory shifts regarding preferences for masculine traits in men has had mixed findings.
It has been suggested that any effects discovered in these studies may be simply a result of the forced-choice methodologies typically used in this kind of research. Women could be simply indicating an aversion towards highly feminized faces without necessarily having a strong preference for masculine ones. This type of research is further confounded by the fact that women have superior facial recognition capabilities in general during the peak fertility period of their menstrual cycle. Thus, women may be simply more attentive to men they already find attractive during peak fertility, without any actual shift in preferences occurring.https://www.sciencedirect.com/science/article/abs/pii/S0010027720300202
Many studies that posit the ovulatory shift hypothesis suffer from other major flaws, such as between-subject designs and the use of self-report questionnaires to measure ovulation.https://www.researchgate.net/publication/260376815_Do_Women%27s_Mate_Preferences_Change_Across_the_Ovulatory_Cycle_A_Meta-Analytic_Reviewhttps://www.researchgate.net/publication/282528474_How_Valid_are_Assessments_of_Conception_Probability_in_Ovulatory_Cycle_Research_Evaluations_Recommendations_and_Theoretical_Implicationshttps://www.researchgate.net/publication/301250987_Standardized_protocols_for_characterizing_women%27s_fertility_A_data-driven_approach
This is a highly problematic methodology, as self-report methods of assessing ovulation are notoriously inaccurate. This method only predicts ovulation with less than 30% accuracy when not combined with hormonal tests.https://www.sciencedirect.com/science/article/pii/S0018506X15300763
Subsequent research that utilized more robust methodologies such as measuring ovulation via hormones combined with correctly powered within-subject designs found no evidence for the ovulatory shift hypothesis with regards to facial masculinity,https://www.researchgate.net/publication/324617541_The_role_of_mating_context_and_fecundability_in_women%27s_preferences_for_men%27s_facial_masculinity_and_beardednesshttps://www.researchgate.net/publication/324854835_No_Compelling_Evidence_That_Preferences_for_Facial_Masculinity_Track_Changes_in_Women's_Hormonal_Statushttps://www.researchgate.net/publication/321079915_La_donna_e_mobile_Lack_of_cyclical_shifts_in_facial_symmetry_and_facial_and_body_masculinity_preferences-A_hormone_based_study in bodily attractivenesshttps://www.researchgate.net/publication/323950415_Fertile_women_evaluate_male_bodies_as_more_attractive_regardless_of_masculinityhttps://www.researchgate.net/publication/333343043_Ovulatory_Shifts_in_Sexual_Desire_But_Not_Mate_Preferences_An_LH-Test-Confirmed_Longitudinal_Study?_sg=UczPCoKjuMecGJSayoAbcd39LBXl-knef503IzdJInJw1hi4O3rvuvwhqGytNSM4CUCAXS1FAaiLY4s and in vocal attractiveness.https://www.researchgate.net/publication/328577575_Do_women%27s_preferences_for_masculine_voices_shift_across_the_ovulatory_cycle?_sg=92LmeqxaSrLGxP6y8rnJmq69Ct1dufMN3Z140XUNXk3W-U-Vs4oC4zcs2l1AGgeGISaQZQWMwbLpw2g
Despite the bulk of the evidence being against it, the jury seems to be still out on whether there exist shifts in female preferences for body masculinity across their menstrual cycle.https://www.sciencedirect.com/science/article/abs/pii/S1090513820300775https://www.sciencedirect.com/science/article/abs/pii/S0306453017308740
It may be that any greater female tendency to commit infidelity during the peak of their ovulatory cycle may be simply due to the surge in hormones that occurs during the menstrual cycle serving to boost their libido. As women seem to exhibit a near unipolar preference for more masculine bodies, if increased libido caused by menstrual hormones increases their openness towards casual sex in general, one would also naturally expect them to therefore select for men with more attractive bodies to pursue these sexual encounters with, and this has been suggested by the research.https://www.sciencedirect.com/science/article/abs/pii/S1090513820300775https://www.sciencedirect.com/science/article/abs/pii/S0306453017308740
However, female sociosexuality itself does not moderate any proposed relationships between ovulation and female facial masculinity preference, as studies that examine this in detail and across broad and large samples find null results.https://psyarxiv.com/qmhg2/<.ref>
/w/Scientific_Blackpill#Rated_strength_is_the_main_predictor_of_men.27s_bodily_attractiveness._No_women_prefer_weak_men
In contrast, as women do not seem to exhibit the same strong preference for greater objective male sexual dimorphism in terms of men's facial bone structure, this may explain the inconsistent and weak effects discovered for female preferences for facial masculinity shifting throughout their menstrual cycles.
Some particularly harsh critics of ovulatory shift research have gone even further, even going so far as to claim that academics whose studies find positive effects in terms of fecund women's preference for masculine faces may be engaged in outright scientific fraud. They state that papers that find positive effects for this phenomenon typically have closed data (meaning you have to take the paper's authors word for it that their results are valid), and papers that find no significant effects often have open data, meaning their data is released and can thus be double-checked and confirmed by interested peers and non-specialists.https://www.sciencedirect.com/science/article/abs/pii/S1090513819302648
To summarize, there is little evidence that women are primed to cuckold their partners with particularly masculine men while they are ovulating or that sociosexuality moderates this, such that more promiscuous women are more likely to employ this mating strategy. It may simply be that ovulation itself raises the female libido,https://journals.sagepub.com/doi/full/10.1177/14747049221148695 making women more open to casual, low investment sexual encounters in general. To the extent that 'dual mating' occurs, it is likely more indicative of general trade-offs between desirability and provision,https://link.springer.com/article/10.1007/s10508-006-9029-3https://www.sciencedirect.com/science/article/abs/pii/S109051382100012Xhttps://link.springer.com/article/10.1007/s40750-017-0070-3 and between perceived nurture and perceived dominance (including risk of aggression) in a male partner as opposed to ovulation consistently making women desire 'good genes' related traits in males as signaled by facial masculinity.
===Hormonal birth control===
In line with the dual-mating hypothesis's claim that a woman's menstrual cycle affects her preference for facial masculinity, some research indicates hormonal birth control does not appear to alter women's preferences regarding the desired level of facial masculinity of a male partner.
Little et al. (2013) examined the partners of women based on their hormonal birth control usage status when the relationships began. The facial masculinity of the partners was evaluated on several objective masculine facial dimorphic traits. Furthermore, a composite image was created for the two groups of men, those who had partners using hormonal birth control when their relationship had begun and those who had not. Both measures found that men partnered with women who reported using hormonal contraception when they had begun dating were more facially feminine compared to the men whose partners were not on hormonal birth control at the beginning of the relationships in question.https://pubmed.ncbi.nlm.nih.gov/23528282/
Another study by the authors found that initiating birth control shifted women's preferences towards masculine faces in laboratory, forced-choice conditions.
However, the cross-sectional design of the partner experiment did not allow the definitive proof of whether this experimental effect was responsible for the association between female hormonal birth control use and a revealed preference for more feminine men.
The author's explanation of this effect was that it suggested that the simulation of the hormonal milieu of pregnancy-induced by hormonal contraception moved women to prefer feminine men as they perceive them as being more likely to invest than masculine men. However, the authors offered an alternate explanation: masculine men find it easier to acquire more attractive female partners, i.e. women at peak fertility. 
Like the ovulatory shift hypothesis research, subsequent studies into the effects of hormonal birth control on female masculinity preference have sharply challenged this finding. Jones et al. (2018) conducted a longitudinal study of the effects of hormones on women's preferences for facial masculinity. They found that salivary hormone levels were not significantly associated with female preferences for facial masculinity, though, n.b, other research has found that salivary measures of hormonal status are generally unreliable, and this may be more salient in the case of the context of this particular research topic, as salivary concentrations of female hormones such as progesterone are generally quite unstable across the menstrual cycle.https://www.sciencedirect.com/science/article/pii/S2666497622000054
More importantly, Jones et al. found a contradictory result for the effects of hormonal birth control administration on female preferences for ideal facial masculinity in experimental conditions. In their study, women on birth control preferred more facially masculine men, contradicting the theoretical underpinning of the hypothesis that birth control will cause women to select more docile and agreeable males for investment-related reasons.https://journals.sagepub.com/doi/10.1177/0956797618760197 Moreover, the authors also found that women who were cycling on and off birth control did not exhibit changes in rated facial masculinity preference while they were taking a break from birth control. 
A later review by Arthur et al. (2022) concurred that the evidence was mixed on whether hormonal contraceptive use altered female preferences for male facial masculinity and other masculine traits. A look at the results collated suggests that length of birth control use, forced choice vs digital manipulation of target photo (the latter finding stronger effects), cycle phase, partnered status, and other confounds seem to have the potential to alter effects in this field of research.https://pubmed.ncbi.nlm.nih.gov/35835214/ p. 6 However, there were some more consistent results found concerning the effects hormonal birth control use has on female mating behaviour, with higher-quality designs suggesting that birth control suppresses women's mate-seeking behaviour. The course of the menstrual cycle seems to be associated with higher self-esteem and a greater self-perception of sexual desirability among women during the cycle's peak fertility phase. This effect is attenuated in hormonal birth control users.ibid, p. 7 Findings are mixed; however, when it comes to whether this alteration in perceptions leads women on birth control to engage less in actual mate-seeking behaviours such as self-beautification and dressing more provocatively.ibid
Findings were more consistent in determining whether birth control makes women more or less likely to engage in mate-guarding or retention behaviours. All studies examined by Arthur et al. found evidence that typically cycling women were likelier to engage in jealous cognitions, actions, and other forms of intrasexual competitive behaviours when in romantic relationships or related to experimental situations that primed such events. The authors asserted that the only null result here did not reliably measure inter-subject variability, nor did it separately examine intersexual and intra-sexual competitive behaviours, which is important as other research has suggested that birth control use may only suppress intrasexual competition among women.ibid, p. 9
Ergo, it is clear that research into the effects of hormonal birth control use suffers from some of the issues that plagued the ovulatory shift research, namely unreliable measures, interference of interaction effects, the use of potentially contradictory experimental paradigms, lack of data on which type of birth control is being used, as they have different mechanisms, low sample sizes, closed data, and issues with control groups. Furthermore, as birth control usage is associated with sociopolitical and demographic traits, selection effects may cause the finding that women on hormonal contraception have more feminine male partners. For example, religiosity (associated with political conservatism) seems to reduce the use of hormonal contraception among young women,https://link.springer.com/article/10.1007/s12119-022-09965-7 and it appears that more conservative women prefer men who exhibit more masculine looks.https://royalsocietypublishing.org/doi/full/10.1098/rsos.191209
This example demonstrates how factors that predict the adoption of hormonal birth control among women may drive any associations with birth control use and partner characteristics in such studies rather than explicit facial masculinity preferences.
Furthermore, some evidence suggests that women exposed to intimate partner violence are less likely to use birth control,https://www.sciencedirect.com/science/article/abs/pii/S0010782415000761M whilst women exposed to such abuse prefer less masculine men overallhttps://www.mdpi.com/1660-4601/17/18/6902https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6698270/ illustrating the kind of demographic confounding factors that could influence cross-sectional ideal preference studies.
In conclusion, the jury is out on whether hormonal control usage significantly alters women's ideal preferences for facial masculinity or their propensity to partner with facially masculine men. However, more consistent evidence suggests hormonal birth control can alter female mating-related behaviour and cognitions more generally.
==Facial hair and attractiveness==
A paper published in January 2020 set out to examine the effect facial morphology had on attractiveness.https://www.researchgate.net/publication/338601050_A_multivariate_analysis_of_women's_mating_strategies_and_sexual_selection_on_men's_facial_morphology
It found that facial masculinity was negatively correlated with attractiveness and that beards significantly increased attractiveness in both short-term and long-term scenarios. The authors produced evidence that found that moderately masculine faces were judged to be the most attractive, followed by intermediate faces, extremely masculine faces, moderately feminine faces (roughly the same between these two), and finally extremely feminine faces as the least attractive.
It should be noted that full-bearded faces significantly affected attractiveness; this was effect was so large that full-bearded, extremely feminine faces (least attractive) were rated as more attractive than clean-shaven moderately masculine faces (most attractive).
The differences in mean attractiveness between extremely feminine faces (least attractive) and moderately masculine faces (most attractive) were less pronounced with full beards than when clean-shaven; this is likely because the beards mask the more unattractive qualities of extremely feminine faces.
Interestingly, a preference for clean-shaven faces is positively associated with reproduction ambition (desire for pregnancy) in single women and negatively associated with reproductive ambition in partnered women. In contrast, a preference for beardedness was positively associated with reproductive ambition in both single and partnered women, which suggests that these women may be viewing beards as a sign of investment potential and maturity. To test for social imprinting of bearded preference during childhood, the authors questioned the women on their father's facial hair status when growing up. The authors found that it did not impact their preferences, indicating a possible biological aspect. They also found that preference for facial masculinity was weakest amongst younger women and it increased with age.
The authors note that their findings on the preference for beardedness in women confirm previous research on this matter (though some research indicates light facial hair is more attractive than full beards and being cleanly shaven).https://www.researchgate.net/publication/305887194_The_masculinity_paradox_Facial_masculinity_and_beardedness_interact_to_determine_women%27s_ratings_of_men%27s_facial_attractivenesshttps://www.researchgate.net/publication/222774518_The_effects_of_facial_hair_manipulation_on_female_perceptions_of_attractiveness_masculinity_and_dominance_in_male_faceshttps://www.researchgate.net/publication/257492193_The_role_of_facial_hair_in_women's_perceptions_of_men's_attractiveness_health_masculinity_and_parenting_abilitieshttps://www.researchgate.net/publication/334143070_Mothers_are_sensitive_to_men%27s_beards_as_a_potential_cue_of_paternal_investmenthttps://www.researchgate.net/publication/332595824_Mating_Strategies_and_the_Masculinity_Paradox_How_Relationship_Context_Relationship_Status_and_Sociosexuality_Shape_Women%27s_Preferences_for_Facial_Masculinity_and_Beardedness Females who scored high on disgust sensitivity (a purported, though unlikely indicator of political conservatism)https://www.researchgate.net/publication/258189644_Disgust_Sensitivity_Political_Conservatism_and_Voting?_sg=XgOMTIFVBNXLqXj1SKYXQCx5ZoUeAxySPikcKsci0LvUxZXBk3_f35B4-Jw4h9lt5D5TqL-vNfLx7kE rated beardedness as more attractive. 
Beardedness is more easily alterable than facial masculinity derived from facial bone structure for most men, at least among those who can grow full beards. There are also online looksmaxxing circles that have discussed the topical usage of drugs such as minoxidil (Rogaine) to support beard growth among men with sparse or otherwise inadequate facial hair coverage.https://articles.beardwiki.com/permanent-minox-beardhttps://arochahairrestoration.com/facial-hair-transplants/ten-things-to-know-before-using-minoxidil-for-facial-hair/https://www.healthline.com/health/minoxidil-beard#summary
One small scale clinical trial has indicated that topical minoxidil use may exhibit some efficiency for this purpose.https://onlinelibrary.wiley.com/doi/abs/10.1111/1346-8138.13312 Another small scale randomized clinical trial conducted on men suffering from Cooley's anemia (which is associated with hypogonadism and other reproductive disturbanceshttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC6179033/) found a large increase in the number of terminal facial hairs after 6 months of treatment with testosterone gel applied to the beard area daily among the treatment group.https://www.researchgate.net/publication/5987226_A_randomized_double-blind_controlled_trial_of_testosterone_gel_treatment_versus_vehicle_control_on_the_facial_hair_of_young_men_with_beta-thalassemia_major The long-term efficiency and safety of these kinds of treatments in the general population is currently unknown.
==Handicap hypothesis==
Despite the lack of strong evidence for a strong female preference for facial masculinity during short-term relationships or otherwise, there is (disputed) evidence that facial masculinity may indeed be weakly linked to overall health and immune system function. This link leads to the argument that women are attracted to testosterone-related traits in men as they 'honestly signal' his immune system's functionality. This feature would have been highly relevant in humanity's evolutionary past due to historically high death rates from diseases.
A longitudinal analysis of public health data found that several markers of immune system function at age 14 were associated with greater facial sexual dimorphism in both sexes in later life.https://www.sciencedirect.com/science/article/abs/pii/S1090513820300350?via%3Dihub
Other studies have also shown that testosterone is directly immunosuppressive, supporting the view that testosterone-related traits may honestly signal the quality of a man's immune system function to some degree.https://www.sciencedirect.com/science/article/pii/S0016648020303300
As it seems the only testosterone-related traits that women exhibit a strong revealed preference for (as measured by studies reporting the association between certain masculine features and lifetime partner count among men) are muscularity, vocal depth, and behavioral dominance, it remains to be seen what role facial masculinity itself plays in signaling good genes.
There appears to be no strong general female preference for this trait. Other purported 'good genes' related signals (like bodily masculinity) are preferred in both short and long-term partners among women (though to perhaps a greater or lesser degree depending on relationship context). This lack of preference shifts cast doubt on the predictions that women do not universally find more masculine faces attractive due to investment-related concerns.
==Other explanations for women's variability in preferences for facial masculinity==
===Not all masculine traits being attractive===
It could be that the lack of a strong female preference for facial masculinity could be partly due to other factors.
Studies have found that there is only a weak correlation between individual masculine features and total facial masculinity,https://royalsocietypublishing.org/doi/abs/10.1098/rspb.2001.1703 so it may be that certain masculine traits increase attractiveness and others decrease it. This heterogeneity among individual masculine features would explain why masculinity is strongly associated with men's physical attractiveness in the public imagination and why there are no strong effects on women's judgments of men's attractiveness on the group level. Some evidence of this hypothesis may be provided by the fact that prominent cheekbones, a trait widely considered to be highly attractive, are negatively correlated with global facial masculinity and is also not substantially sexually dimorphic.https://link.springer.com/article/10.1007/s40750-018-0105-4
Vertically narrow eyes, another masculine trait that is generally considered attractive, is also not correlated with global facial masculinity, despite being sexually dimorphic.https://link.springer.com/article/10.1007/s00265-020-02894-1
Thus, there is substantial evidence that individual male sexually dimorphic facial traits do not even correlate with each other highly, meaning the main source of global facial masculinity is likely just the sheer robustness and size of the face, which is likely largely unrelated to the aesthetic quality of the face.
It could also be that certain masculine features such as broad chins are generally beneficial to attractiveness, and some are beneficial or neutral, such as a pronounced brow ridge. In contrast, some masculine traits, such as a broad nose, may often be generally detrimental to attractiveness. It is also a fact that some traits that are generally considered attractive and popularly associated with masculinity, such as the angularity of the jaw, are only sexually dimorphic to a minor degree.https://www.sciencedirect.com/science/article/abs/pii/000294165490127X
Research into the individual components of facial attractiveness has found that the only aspect of objective masculine dimorphism that is consistently found to be attractive in men is darker coloring, that is, darker hair, brows, and an overall ruddy melanized skin complexion (within races).https://www.sciencedirect.com/science/article/abs/pii/S1090513815000859?via%3Dihub
This type of complexion is associated with higher testosterone levels in humans and many other mammals.
Thus, it seems clear that individual elements of facial masculinity affect women's perceptions of men's attractiveness distinctly and that these traits are often not highly correlated with each other. These two facts partially explain the contradictory findings in studies that examine women's preferences for this trait.
===Harsh vs. abundant ecologies===
Another explanation for the inconsistently regarding women's preferences for sexual dimorphism in male faces is that environmental contexts, such as disease load and resource abundance/scarcity, affect women's preferences for facial masculinity.
There are two main seemingly completely contradictory theories on how ecology could potentially influence women's preferences for facial masculinity.
The first states that women in harsh ecologies would be expected to prefer facially masculine men. These men would be more physically formidable, more aggressive, and more likely to prevail in male intrasexual competitions and achieve a high dominance rank and so forth.
The handicap theory of masculinity would also predict these men to have superior immune systems that women in areas with a high parasite load and disease burden would be expected to be particularly attracted to. In support of this theory, Penton-voak et al. (2004) found that women in a country with a high parasite load (Jamaica) generally preferred masculinized faces compared to a country with a low parasite load (Great Britain).https://www.sciencedirect.com/science/article/abs/pii/S1090513804000510
They also theorized that apart from parasite load, women in Jamaica may generally expect low levels of paternal investment from their men, and thus pay less attention to cues indicating a willingness to invest, essentially the nice-guy physiognomy associated with a more feminine face. Their finding may also indicate that women with an overall faster life history strategy may prefer facially masculine men.
However, this study did not consider the possibility that one's race may affect one's preference for masculinity/femininity in an opposite sex partner's face, as sexual dimorphism does differ by race/ethnicity.
The second theory, proposed by Scott et al. (2014) is that preferences for sexual dimorphism in human faces are evolutionary novel and largely contained to modern industrial societies.
Furthermore, Scott and her team produced evidence that directly contradicted the immunocompetence hypothesis of facial masculinity, finding that disease burden was related to lesser preference for masculine male faces, cross-culturally.https://www.pnas.org/content/111/40/14388#sec-1 This also means that women in countries with a higher human developmental index also have a stronger preference for facial masculinity, though in most cultures examined women had a stronger preference for neutral/feminine male faces for long-term relationships.
As the perceptions of facially masculine men (nastiness, aggressiveness etc) varied substantially by culture, the researchers speculated that this female preference for more facially masculine men in more developed societies could be driven by cultural exposure to more masculine faces, an association between HDI and facial masculinity itself in men, or the fact that greater social stratification could result in a preference for more masculine males (as more aggressive men may ascend such dominance hierarchies easier and be more ruthless in their pursuit of more unequally distributed resources.)
In support of the second hypothesis, Kleisner (2021) found that men from countries with a high HDI (Whites) did have more masculine faces than the women of their countries, perhaps partially explaining this effect.
Furthermore, a team of researchers in 2019 analyzing a cross-cultural sample of female raters replicated the finding that women in countries with higher human developmental indices had a stronger preference for facially masculine men, https://www.nature.com/articles/s41598-019-39350-8#Sec2 and other studies have found that facial sexual dimorphism (in both sexes) has no significant influence on attractiveness judgements among participants drawn from rural, underdeveloped areas.https://link.springer.com/article/10.1007/s40750-021-00173-5
They emphasized that their findings did not support certain predictions of the 'good genes' theory. The authors attributed some of this effect to increased mass media exposure and most of it to women in these more prosperous countries being more sexually liberated and economically secure, thus making them freer to make costly mate-choices.https://www.nature.com/articles/s41598-019-39350-8#Sec2
The evidence they cited that more masculine men are generally more sexually successful was very weak. However, it is flatly contradicted by meta-analyses into this subject, noted above in this article, which includes data from Western samples. This study does seem to provide further evidence that promiscuous women tend to prefer masculine men more, though even in the most developed countries, a substantial proportion of women preferred more feminized male faces in the 'forced-choice paradigm used in this study. There was no 'neutral' option for a man with an intermediate degree of facial masculinity, which may be ideal according to the goldilocks zones principle.
Some of the variability in women's attraction to masculinity may be explained by different genetic dispositions to preferring such features in males. For example, one study found a strongly significant effect for women and girls with a fast life history, i.e., with an earlier pubertal timing and an earlier onset of sexual activity, having a greater preference for masculinity,Batres, C., & Perrett, D. I. (2016). Early Menarche is Associated With Preference for Masculine Male Faces and Younger Preferred Age to Have a First Child. Evolutionary Psychology, 14(2), 147470491663787. doi:10.1177/1474704916637876 however, the link is weak. No other study has shown such a link.
===Halo effect===
Finally, it may be that beauty (which is mostly unrelated to facial masculinity) may moderate the effects of facial masculinity on facial attractiveness ratings.
Yang et al. (2015) found that there was a general preference for masculinized faces when comparing two attractive morphs. Still, the results were more mixed when comparing less attractive morphs, with women preferring the androgynous morphs during the low attractiveness condition, as measured by eye fixations and dwell time.https://www.sciencedirect.com/science/article/abs/pii/S0191886914007132
It may be that less attractive masculine men are more likely to be perceived as aggressive, arrogant, and several other undesirable traits, while more attractive masculine men are not, due to the halo effect. In other words, it could be that ugly and masculine men are seen as threatening, and attractive and masculine men are perceived as hot and dominant.
===Women perceive masculinity more holistically===
Pivonkova et al. (2011) conducted a principle component analysis (PCA) of several (15) anthropometric facial landmarks that have been found to differ by sex. They found no significant relationship between the principle components associated with facial masculinity and women's perceptions of the level of masculinity of the faces, suggesting that women evaluate a man's perceived masculinity in a more holistic way, while men rely more on objective features, such as jaw bone prominence and facial neoteny in making their judgements of the masculinity of faces.https://pubmed.ncbi.nlm.nih.gov/21901645/ This could explain why some studies find null effects for objective masculine and female rated attractiveness of men, as women seem to generally rely less on objective facial landmarks when making judgements of a face's level of masculinity.
==Male intrasexual competition==
Another factor that could have played a role in the evolutionary development of sexually dimorphic facially masculine traits is intrasexual competition or competition between ancestral males for access to women and resources. It could be that morphologically masculine facial features could have developed in men because they are indicative of greater physical prowess (so they are an honest signal of this) in these men, or they could merely serve to intimidate other males without contributing much to men's fighting ability (that is, this trait is a partially deceptive signal).
In the cultural milieu in which most modern dating occurs, especially in modern industrialized societies, many would find it doubtful that facial masculinity would play much of a role in mediating male success in dominance competitions. There seems to be limited scope for direct physical confrontations to play a prominent role in determining access to mates due to such factors as the relative efficiency of the modern legal system (at least among adults, where penalties for overtly violent acts are harsher) and the general social undesirability of such actions and the relatively low level of violence in industrialized societies. Other male competitive strategies, such as verbal derogation, displays of physical prowess, resource displays, self-enhancement, and bullying would seem to be more commonly utilized and effective intrasexual competition tactics by males.https://labs.la.utexas.edu/buss/files/2015/09/evolution_intrasexual_competition_1988_jpsp.pdfhttps://www.sciencedirect.com/science/article/abs/pii/0162309594900256
However, there does seem to be evidence that sheer physical intimidation can play a significant role in driving mating outcomes. This is caused either via indirect female choice for physical dominance, male coercion, women selecting for men of high position in male hierarchies (which is likely influenced by their physical dominance over other men) or male contests effectively limiting each other's access to women (probably a mix of all of these), at least in specific social contexts.
In light of the apparent importance of physical dominance in driving men's mating success, it is interesting that the role facial masculinity plays in determining the outcomes of these dominance contests and men's mating outcomes seems limited.
For instance, Hill et al. (2013) attempted to examine the strength of selection on various physically masculine traits (facial masculinity, body size, height, vocal depth) on men's mating attractiveness by reviewing how much they contributed to either female ratings of attractiveness (presumed to be a proxy for direct female sexual selection) or ratings of physical dominance (determined by estimates of fighting ability) and their relative contributions to male mating success (as measured by sexual partner count).
They found that of the physical traits listed, only "girth" or a crude measure of raw physical size (exclusive of height) significantly predicted mating success in this sample (of the traits examined), with men's facial masculinity playing no role, either under conditions of presumed female selection (attractiveness ratings) or the conditions of a male physical intrasexual competition (fighting success ratings).https://www.sciencedirect.com/science/article/abs/pii/S1090513813000615
Similarly, Kordesmeyer et al. (2018) found that of the physical traits he examined, only those related to success in male-male competition (again as judges by estimates of fighting ability) predicted men's mating success (though relatively weakly).http://larspenke.eu/pdfs/Kordsmeyer_et_al_2018_-_Intra-_vs_intersexual_selection_on_human_males.pdf In this study, while the men's facial masculinity was associated with men's evaluations of other men's dominance, it was still ultimately unrelated to the male subject's mating success.
These findings concord with extensive research that discovered that male facial masculinity is not significantly related to their lifetime sexual success or fertility, while sheer physical size is, albeit rather weakly when considered on a broad level of a lifespan and in more diverse samples.https://www.biorxiv.org/content/10.1101/2020.03.06.980896v1/
Thus, while facial masculinity does appear to be salient to some degree in driving perceptions of physical dominance,https://www.sciencedirect.com/science/article/pii/S1090513820300830 it is unclear what role facial masculinity plays in actually intimidating other males. Thus it seems likely that facially masculine sexually dimorphic traits merely evolved to serve as "facial buttressing," with a robust facial structure serving to protect the vital areas of the face,https://onlinelibrary.wiley.com/doi/abs/10.1111/brv.12112 (especially the eyes, as eye structure is quite sexually dimorphic,https://www.futurelearn.com/info/courses/forensic-facial-reconstruction/0/steps/25656 and the eyes are particularly vulnerable) from blows as men were presumably more likely to die from physical violence throughout their evolutionary history than women. A male sexual preference for physical neoteny in women would also decrease their facial masculinity in the absence of strong selection pressures exerted on them for this trait in terms of viability.
It could also be that muscularity is seen as an "offensive" tool in male intrasexual competition, and facial masculinity is seen as a "defensive" tool. That is, muscularity may be much more critical in driving perceptions of threat, which may contribute to dominance perceptions and, therefore, male peer status. At the same time, while facial masculinity does appear to factor into perceptions of overall formidability, it may play much less of a role in actually driving the physical intimidation of other men when compared to sheer size and bulk.
==Facial masculinity and other individual differences==
* A study which used a machine learning algorithm to predict and rate political candidates levels of various facial traits did not find a significant association between the candidate's ideology and their level of facial masculinity.https://www.nature.com/articles/s41598-023-31796-1#Sec16 However, they used fWHR to determine facial masculinity and this only seems to be sexually dimorphic among younger men, and to a weak degree,https://royalsocietypublishing.org/doi/10.1098/rsos.211500 casting doubt on this finding. Furthermore, fWHR, as opposed to raw facial width, may be a poor metric in general, in terms of predicting the things it purports to predict.https://incels.wiki/w/Facial_width-to-height_ratio#Brief_overview_of_fWHR_research_and_meta_commentary
* Facially masculine men are perceived as being more prone to criminality and violent behavior,https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6818315/ and they may actually be so.https://www.sciencedirect.com/science/article/abs/pii/S109051380900124Xhttps://research.usc.edu.au/esploro/outputs/99620908502621?institution=61USC_INST&skipUsageReporting=true&recordUsage=false
* Men and women with more masculine faces are generally seen as more competent than those with more feminine faces.https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0181306
* Facial masculinity seems positively correlated with behaviorally masculine behavior in general, such as being more competitivehttps://pubmed.ncbi.nlm.nih.gov/18796396/ risk toleranthttps://ex.hhs.se/dissertations/220623-FULLTEXT02.pdf and impulsive, though effects seem to differ by sex.https://www.tandfonline.com/doi/abs/10.1080/13504851.2013.826861
==See also==
*List of aesthetics
*Beauty
*Body attractiveness
*Neoteny
*Ogrecel
*Cutecel
==References==
Category:Aesthetics
Category:Face