Partnership status and the temporal context of relationships influence human female preferences for sexual dimorphism in male face shape

Sharing and Receiving Eye-Contact Predicts Mate Choice After a 5-Minute Conversation: Evidence from a Speed-Dating Study

In popular narratives, the first date with a potential mate often centers on their gaze as embodiment of interest and attraction. However, evidence is still lacking on the role of eye-contact as a potent signal in human social interaction in the context of dating. In addition, behavioral mechanisms of mate selection are not well understood. In the present study, we therefore examined mutual eye-contact and its influence on mate choice by applying dual mobile eye-tracking during naturalistic speed-dates. A total of 30 male and 30 female subjects attended four speed-dates each (N = 240). Subjects were more likely to choose those dating partners with whom they shared more eye-contact with. In addition, perceived attractiveness played an important role for mate choice. Interestingly, receiving but not giving eye-contact also predicted individual mate choice. Eye-contact thus acts as an important signal of romantic attraction when encountering a dating partner.

Choosing Upper Blepharoplasty, Infra-brow Lift, and Forehead Lift in Asians: An Algorithmic Approach from Personal Experience

BACKGROUND

Eyelid surgery is a cosmetic procedure performed worldwide in the field of plastic surgery. However, achieving optimal outcomes for the upper eyelids presents a challenge, necessitating careful patient selection and appropriate surgical choices.

OBJECTIVES

This article aims to provide recommendations for selecting the most suitable surgical procedure among three commonly performed treatments for aged upper eyelids.

METHODS

A retrospective cohort study was conducted from October 2020 to May 2022, involving 518 patients. Pre- and postoperative photographs were analyzed to evaluate changes in the distance between the eyelids and brows. Notably, patients who habitually use the frontalis muscle to manage upper eyelid redundancy showed significant variations in the lid-brow distance after eyelid surgery.

RESULTS

The study confirmed that addressing skin laxity through upper blepharoplasty or infra-brow excision reduced the stimulus for frontalis activity, resulting in true brow ptosis. However, the degree of compensatory frontalis movement differed among individuals, and changes in the lid-brow distance observed before and after the photos were influenced by various factors. As a result, obtaining clear numerical data regarding the changes in the lid-brow distance following eyelid surgery proved challenging. Nevertheless, after analyzing 518 cases, the author has classified the patients into three groups, which can contribute to more predictable and satisfying outcomes.

CONCLUSION

Based on the analysis of pre- and postoperative results from 518 patients, this study recommends specific strategies to enhance patient satisfaction. The proposed treatment algorithm may assist beginner surgeons in avoiding angry or tired-looking eyes after periorbital rejuvenation.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

No evidence that sociosexual orientation moderates effects of conception probability on women's preferences for male facial masculinity

Although many researchers have proposed that women will show stronger preferences for male facial masculinity when conception probability is high, empirical tests of this hypothesis have produced mixed results. One possible explanation for these inconsistent findings is that effects of conception probability on women's preferences for facial masculinity are moderated by additional factors not typically considered in these empirical tests. One such potential moderator is individual differences in women's openness to uncommitted sexual relationships (i.e., individual differences in women's sociosexual orientation); women who are more open to uncommitted sexual relationships might show stronger positive effects of conception probability on masculinity preferences, as their sexuality is more overt and sexual attitudes and behaviours are more diversified. Consequently, we analysed data from three independent samples (N = 2304, N = 483, and N = 339) to assess whether sociosexual orientation moderates the hypothesised positive effect of conception probability on women's facial masculinity preferences. Analyses showed no evidence that higher conception probability increased preferences for facial masculinity or that sociosexual orientation moderated the effect of conception probability on women's preferences for facial masculinity. While it remains possible that factors other than sociosexual orientation moderate effects of conception probability on masculinity preferences, our null results suggest that the mixed results for the effects of conception probability on facial masculinity preferences in previous studies are unlikely to be a consequence of failing to consider the moderating role of sociosexual orientation.

Women's Mating Strategies and Mate Value Are Associated with Viewing Time to Facial Masculinity

Sexual selection has shaped women's preferences for ideal physical features in men that signal good health. Facial masculinity is often used as a proxy in signaling health, viability, and disease resistance, and it is thought to be attractive because it advertises heritable benefits. Preferences for facial masculinity are also associated with individual differences in one's sociosexuality and mate value, where women oriented toward a short-term mating orientation and are of high mate value may prefer men with masculine features. The current study examined women's sociosexuality and mate value (i.e., self-rating of overall desirability) in rating attractiveness and visual attention to facial masculinity in men's faces using an eye-tracking task. Overall, women (N = 72) did not show any significant preferences for men with masculinized over feminized faces. However, women who scored high on sociosexuality (i.e., unrestricted sociosexuality) and mate value demonstrated increased visual attention and looking frequency to masculinized over feminized faces. The study highlights the unique role of cognitive mechanisms in visually assessing a potential mate and how individual differences in short-term mating strategies and mate value may moderate those preferences. These findings underscore the importance of examining individual differences in mate preferences research.

The role of hormones in attraction and visual attention to facial masculinity

The current study investigated the ovulatory shift hypothesis, which suggests that women prefer more masculine traits when estradiol is high, and progesterone is low (E/P ratio). The current study used an eye tracking paradigm to measure women's visual attention to facial masculinity across the menstrual cycle. Estradiol (E) and progesterone (P) were collected to determine if salivary biomarkers were associated with visual attention to masculine faces in a short- and long-term mating context. Women (N = 81) provided saliva samples at three time points throughout their menstrual cycle and were asked to rate and view men's faces that had been manipulated to appear feminine and masculine. Overall, masculine faces were viewed longer compared to feminine faces and this was moderated by mating context, where women viewed masculine faces longer for a long-term relationship. There was not any evidence suggesting that E/P ratio was associated with preferences for facial masculinity, but there was evidence to suggest that hormones were associated with visual attention to men in general. In line with sexual strategies theory, there was evidence to suggest that mating context and facial masculinity are important in mate choice; however, there was no evidence to suggest that women's mate choice was associated with shifts across the menstrual cycle.

Assortative mate preferences for height across short-term and long-term relationship contexts in a cross-cultural sample

Height preferences reflecting positive assortative mating for height—wherein an individual’s own height positively predicts the preferred height of their mate—have been observed in several distinct human populations and are thought to increase reproductive fitness. However, the extent to which assortative preferences for height differ strategically for short-term versus long-term relationship partners, as they do for numerous other indices of mate quality, remains unclear. We explore this possibility in a large representative sample of over 500 men and women aged 15–77 from Canada, Cuba, Norway and the United States. Participants’ own heights were measured, and they indicated their height preferences for a long-term and short-term mate using graphic stimuli containing metric indices. Replicating the “male-taller norm,” participants on average preferred taller-than-average male mates, and shorter-than-average female mates. Positive assortative preferences for height were observed across sexes and samples, however the strength of these height preferences varied with relationship context for men, and not for women. Taller men preferred relatively shorter women for short-term relationships than for long-term relationships, indicating stronger assortative preferences for height in a long-term context. These results provide preliminary evidence that, in addition to mate preferences for other physical traits related to mate quality such as masculinity in the body, face, and voice, assortative preferences for height do vary as a function of expected relationship length, but this was surprisingly only observed in preferences for female height.

Hormonal contraceptives as disruptors of competitive behavior: Theoretical framing and review

Emerging evidence suggests that hormonal contraceptives (HCs) impact psychological outcomes through alterations in neurophysiology. In this review, we first introduce a theoretical framework for HCs as disruptors of steroid hormone modulation of socially competitive attitudes and behaviors. Then, we comprehensively examine prior research comparing HC users and non-users in outcomes related to competition for reproductive, social, and financial resources. Synthesis of 46 studies (n = 16,290) led to several key conclusions: HC users do not show the same menstrual cycle-related fluctuations in self-perceived attractiveness and some intrasexual competition seen in naturally-cycling women and, further, may show relatively reduced status- or achievement-oriented competitive motivation. However, there a lack of consistent or compelling evidence that HC users and non-users differ in competitive behavior or attitudes for mates or financial resources. These conclusions are tentative given the notable methodological limitations of the studies reviewed. Implications and recommendations for future research are discussed.

Gender Biases in the Accuracy of Facial Judgments: Facial Attractiveness and Perceived Socioeconomic Status

Many studies demonstrate that people form their first impression of a stranger based on facial appearance, and these impressions influence their subsequent decisions and behaviors. However, much less research has examined the factors that moderate the accuracy of first impressions based on a photo of face. The present study included three experiments to explore gender differences in the accuracy of impressions based on faces. The results showed that people judge facial attractiveness more accurately for female faces than for male faces while giving more accurate wealth judgments for male faces than for female faces. Interestingly, although we did not find a significant correlation between confidence ratings and the accuracy of wealth rating, we recognized a significant moderate correlation between confidence ratings and the accuracy of attractiveness ratings when female participants rated male faces. To our knowledge, the present study is the first to reveal gender biases in the accuracy of impression judgments based on facial appearance. These findings imply a significant influence of traditional gender roles on accurate facial judgments.

Attraction to Physical and Psychological Features of Children in Child-Attracted Persons

In an online survey of 274 self-identified child-attracted persons (CAPs), we examined the attraction ratings given to sets of 9 physical and 12 psychological features of children, and asked CAPs to identify additional features that were not listed. We also examined the relationships between these attraction ratings and attraction to children dimensions (age mono-/polymorphism, exclusivity of attraction to children, and gender attraction), history of falling in love with a child, and detected sexual offending history. There was relatively little differentiation across physical features and psychological features; all averages were approximately 4 or higher on a 5-point scale. Attraction ratings were mostly weakly and inconsistently related to our other study variables. The exception was that CAPs who had fallen in love with a child rated 11 out of 12 psychological features as more attractive than CAPs who had not fallen in love with a child, with small to moderate effect sizes. These two groups did not differ in ratings for physical features. Our qualitative content analysis of participant-suggested features revealed six physical themes (inter alia, face and head, children's bodies) and five psychological themes (inter alia, personality, harmlessness) that were important to CAPs' attraction to children.

Facial threat affects trust more strongly than facial attractiveness in women than it does in men

Trust is essential in initiating social relationships. Due to the differential evolution of sex hormones as well as the fitness burdens of producing offspring, evaluations of a potential mating partner's trustworthiness likely differ across sexes. Here, we explore unknown sex-specific effects of facial attractiveness and threat on trusting other-sex individuals. Ninety-three participants (singles; 46 women) attracted by the other sex performed an incentivized trust game. They had to decide whether to trust individuals of the other sex represented by a priori-created face stimuli gradually varying in the intensities of both attractiveness and threat. Male and female participants trusted attractive and unthreatening-looking individuals more often. However, whereas male participants' trust behavior was affected equally by attractiveness and threat, female participants' trust behavior was more strongly affected by threat than by attractiveness. This indicates that a partner's high facial attractiveness might compensate for high facial threat in male but not female participants. Our findings suggest that men and women prioritize attractiveness and threat differentially, with women paying relatively more attention to threat cues inversely signaling parental investment than to attractiveness cues signaling reproductive fitness. This difference might be attributable to an evolutionary, biologically sex-specific decision regarding parental investment and reproduction behavior.

Differential effects of resource scarcity and pathogen prevalence on heterosexual women's facial masculinity preferences

The present research focused on how environmental harshness may affect heterosexual women's preferences of potential male mates' facial characteristics, namely masculinity-femininity. The evidence on this issue is mixed and mostly from Western samples. We aimed to provide causal evidence using a sample of Turkish women and Turkish male faces. A video-based manipulation was developed to heighten environmental harshness perceptions. In the main experiment, participants were primed with resource scarcity, pathogen prevalence or neither (control). They then saw masculinised vs. feminised versions of the same faces and indicated the face that they would prefer for a long-term relationship and separately rated the faces on various dimensions. In general, masculinised faces were perceived as slightly more attractive, slightly healthier and much more formidable. A multilevel Bayesian model showed that pathogen prevalence lowered the preference for masculinised faces while resource scarcity weakly elevated it. The overall drop in attractiveness ratings in cases of high perceived pathogen prevalence, one of the strongest effects we observed, suggests that during epidemics, the formation of new relationships is not a favourable strategy. Implications for evolutionary theories of mate preference are discussed.

Testing Mate Choice Hypotheses in a Transitional Small Scale Population

Objective

Tests of theories of mate choice often rely on data gathered in White, industrialised samples and this is especially the case for studies of facial attraction. Our understanding of preferences for sexual dimorphism is currently in flux and a number of hypotheses require testing in more diverse participant samples. The current study uses opportunistically gathered facial dimorphism preference data from 271 participants in rural Nicaragua, and 40 from the national capital Managua. We assess pre-registered hypotheses drawn from sexual selection theory, and from more recent approaches which consider the impacts of economic development and cultural ‘modernisation’ on mate preferences.

Methods

Participants verbally reported demographic data, and indicated preferences for five male and five female pairs of faces manipulated to differ in sexually dimorphic facial structure based on a sample of Salvadoran individuals.

Results

While urban participants showed a preference for more feminine female faces, this preference was not evident in the rural participants. Neither urban nor rural participants showed any directional preference for masculinised/feminised male faces. Furthermore, there was no support for any other pre-registered hypothesis.

Conclusions

Our results are consistent with previous studies showing no interest in facial dimorphism in less globally-acculturated, or market integrated, populations. Together, this suggests that while facial dimorphism may be subject to systematically varying preferences amongst some low-fertility, industrialised populations, it is not a feature which is likely to have been important in ancestral populations. We call for further work attempting to replicate well known mate choice phenomena in more diverse samples.

Facial attractiveness and preference of sexual dimorphism: A comparison across five populations

Despite intensive research, evolutionary psychology has not yet reached a consensus regarding the association between sexual dimorphism and attractiveness. This study examines associations between perceived and morphological facial sexual dimorphism and perceived attractiveness in samples from five distant countries (Cameroon, Colombia, Czechia, Iran and Turkey). We also examined possible moderating effects of skin lightness, averageness, age, body mass and facial width. Our results suggest that in all samples, women's perceived femininity was positively related to their perceived attractiveness. Women found perceived masculinity in men attractive only in Czechia and Colombia, two distant populations. The association between perceived sexual dimorphism and attractiveness is thus potentially universal only for women. Across populations, morphological sexual dimorphism and averageness are not universally associated with either perceived facial sexual dimorphism or attractiveness. With our exploratory approach, results highlight the need for control of which measure of sexual dimorphism is used (perceived or measured) because they affect perceived attractiveness differently. Morphological averageness and sexual dimorphism are not good predictors of perceived attractiveness. It is noted that future studies should use samples from multiple populations to allow for identification of specific effects of local environmental and socioeconomic conditions on preferred traits in unmanipulated local facial stimuli.

Modeling individual preferences reveals that face beauty is not universally perceived across cultures

Facial attractiveness confers considerable advantages in social interactions,^1,2 with preferences likely reflecting psychobiological mechanisms shaped by natural selection. Theories of universal beauty propose that attractive faces comprise features that are closer to the population average³ while optimizing sexual dimorphism.⁴ However, emerging evidence questions this model as an accurate representation of facial attractiveness,5, 6, 7 including representing the diversity of beauty preferences within and across cultures.8, 9, 10, 11, 12 Here, we demonstrate that Western Europeans (WEs) and East Asians (EAs) evaluate facial beauty using culture-specific features, contradicting theories of universality. With a data-driven method, we modeled, at both the individual and group levels, the attractive face features of young females (25 years old) in two matched groups each of 40 young male WE and EA participants. Specifically, we generated a broad range of same- and other-ethnicity female faces with naturally varying shapes and complexions. Participants rated each on attractiveness. We then reverse correlated the face features that drive perception of attractiveness in each participant. From these individual face models, we reconstructed a facial attractiveness representation space that explains preference variations. We show that facial attractiveness is distinct both from averageness and from sexual dimorphism in both cultures. Finally, we disentangled attractive face features into those shared across cultures, culture specific, and specific to individual participants, thereby revealing their diversity. Our results have direct theoretical and methodological impact for representing diversity in social perception and for the design of culturally and ethnically sensitive socially interactive digital agents.

•

We modeled individual preferences for attractive faces in two cultures

•

Attractive face features differ from the face average and sexual dimorphism

•

Instead, culture and individual preferences shape attractive face features

•

Attractive face features from a culture are used to judge other-ethnicity faces

How and why patterns of sexual dimorphism in human faces vary across the world

Sexual selection, including mate choice and intrasexual competition, is responsible for the evolution of some of the most elaborated and sexually dimorphic traits in animals. Although there is sexual dimorphism in the shape of human faces, it is not clear whether this is similarly due to mate choice, or whether mate choice affects only part of the facial shape difference between men and women. Here we explore these questions by investigating patterns of both facial shape and facial preference across a diverse set of human populations. We find evidence that human populations vary substantially and unexpectedly in both the magnitude and direction of facial sexually dimorphic traits. In particular, European and South American populations display larger levels of facial sexual dimorphism than African populations. Neither cross-cultural differences in facial shape variation, sex differences in body height, nor differing preferences for facial femininity and masculinity across countries, explain the observed patterns of facial dimorphism. Altogether, the association between sexual shape dimorphism and attractiveness is moderate for women and weak (or absent) for men. Analysis that distinguishes between allometric and non-allometric components reveals that non-allometric facial dimorphism is preferred in women's faces but not in faces of men. This might be due to different regimes of ongoing sexual selection acting on men, such as stronger intersexual selection for body height and more intense intrasexual physical competition, compared with women.

Effects of Women's Short-Term Mating Orientation and Self-Perceived Attractiveness in Rating and Viewing Men's Waist to Chest Ratios

Women's mating strategies are dependent on multiple factors, such as identifying which men advertise physical features indicating high genetic quality, as well as identifying which men are willing to invest in offspring. Research has suggested that women pursuing short-term mating prioritize physical attraction to facilitate the acquisition of good genes. Although it is known that physical characteristics are important in mate choice, research investigating the saliency of physical features in assessing male fitness has not been readily explored. The current study used an eye-tracking paradigm to investigate the role of short-term mating in women and their attraction and visual attention to men's waist to chest ratios (WCRs). Women's short-term mating orientation (N = 130) was associated with attraction to men with low WCRs; however, their visual attention was not influenced by their mating strategy. Interestingly, women who perceived themselves as attractive rated men with low WCRs as more attractive and allocated attentional resources to physical features important in mate choice, such as the head and midriff region. The findings from this study lend some support to sexual strategies theory (Buss & Schmitt, 1993) and strategic pluralism (Gangestad & Simpson, 2000), and they suggest that mate preferences may be calibrated as a function of one's mate value.

Effects of Male Facial Masculinity on Perceived Attractiveness

Studies suggest that high levels of masculinity in men can be a signal of 'better genes' as well as low parental investment. It is the trade-off between these two qualities that has led to the hypothesis that women's preferences for male masculinity are condition-dependent, yet, not all studies support this hypothesis. In addition, there is evidence that more average faces would be perceived as more attractive. Here we study the variation in masculinity preferences of a cohort of heterosexual women (n=769), using manipulated 3D faces of male subjects. We used linear mixed models to test for effects of various covariates such as relationship status, use of hormonal contraception, sociosexual orientation and self-perceived attractiveness on preference for masculinity. Our results show that women's sociosexual orientation has a positive correlation with masculinity preference while using hormonal contraception decreases this preference. None of the other covariates displayed any significant effect on masculinity preference. The initial level of masculinity of the faces (very low, low, average, high and very high) was also shown to affect this preference, where we found a significant preference for higher masculinity in the very low and average group, while no preference was found in the other groups. Our findings support the notion that condition-dependent variables have very small effects, if any, on women's preference for masculinity in men.

Do We See Masculine Faces as Competent and Feminine Faces as Warm? Effects of Sexual Dimorphism on Facial Perception

Previous research on non-facial features demonstrated that masculinity and femininity correlated highly with perceived competence and warmth, respectively. Several studies focused on dimorphic facial cues and found an association between masculine faces and competence. However, there's no study exploring the association between facial dimorphism and social judgment both using explicit and implicit experimental paradigms, i.e. Triad Classification Task, Implicit Associate Task. This study examined the association of masculinity/femininity and competence/warmth via explicit and implicit measures in three experiments. The results showed that participants saw feminine/masculine faces as more consistent with warmth/competence for both male and female faces. Besides, it was found that the above associations were more obvious in female participants. The current studies extended research of effects of dimorphic facial cue in social judgment and provided direct evidence linking facial masculinity with perceived competence, and facial femininity with perceived warmth.

Effects of a dopamine agonist on trusting behaviors in females

Trust is central to bonding and cooperation. In many social interactions, individuals need to trust another person exclusively on the basis of their subjective impressions of the other's trustworthiness. Such impressions can be formed from social information from faces (e.g., facial trustworthiness and attractiveness) and guide trusting behaviors via activations of dopaminergic brain regions. However, the specific dopaminergic effects on impression-based trust are to date elusive. Here, in a double-blind, placebo-controlled, within-subject design, we administrated a D2/D3 dopamine agonist (pramipexole) to 28 healthy females who subsequently played a one-shot trust game with partners of varying facial trustworthiness. Our results show that by minimizing facial attractiveness information, we could isolate the specific effects of facial trustworthiness on trust in unknown partners. Despite no modulation of trustworthiness impressions, pramipexole intake significantly impacted trusting behaviors. Notably, these effects of pramipexole on trusting behaviors interacted with participants' hormonal contraceptive use. In particular, after pramipexole intake, trust significantly decreased in hormonal contraceptive non-users. This study fills an important gap in the experimental literature on trust and its neural dynamics, unearthing the cognitive and neural modulations of trusting behaviors based on trustworthiness impressions of others.

Misperceptions of opposite-sex preferences for thinness and muscularity

Thin and muscular have been characterized as ideals for women and men, respectively. Little research has investigated whether men and women have accurate perceptions of opposite-sex preferences of thinness and muscularity. Further, no study has explored whether opposite-sex perceptions of thinness and muscularity preferences differ for short-term and long-term relationships. The present study set out to address these questions. We used interactive 3D human models to represent bodies varying in size (body mass index/BMI weight scaled by height) and body composition. University-aged (18-31) White European heterosexual men and women were asked to choose their own and ideal body shape, the ideal body shape for a short- and a long-term partner, and the body shape they thought the opposite-sex would most like for short- and long-term partners. Women overestimated the thinness that men prefer in a partner and men overestimated the heaviness and muscularity that women prefer in a partner. These misperceptions were more exaggerated for short-term relationships than for long-term relationships. The results illustrate the importance of investigating misperceptions of opposite-sex preferences and raise the possibility that correcting misperceptions might have utility in reducing body dissatisfaction or eating disorders.

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.

No evidence that partnered and unpartnered gay men differ in their preferences for male facial masculinity

Women’s preferences for masculine characteristics in men’s faces have been extensively studied. By contrast, little is known about how gay men respond to masculine facial characteristics. One area of disagreement in the emerging literature on this topic is the association between gay men’s partnership status and masculinity preference. One study found that partnered gay men showed stronger preferences for masculine faces than did single gay men, while another study found that partnered gay men showed weaker preferences for masculine faces than did single gay men. We re-examined this issue in a sample of 618 gay men, finding no significant difference between partnered and single gay men’s masculinity preferences. Together with the mixed previous findings, our null result suggests that the effect of partnership status on gay men’s face preferences is not robust.

Influence of sexual dimorphism on the attractiveness evaluation of one's own face

The present study aimed to explore the influence of sexual dimorphism on the evaluation of the attractiveness of one's own face. In the experiment, a masculinized and a feminized version of the self-faces of the participants were obtained by transferring the original faces toward the average male or female face. The participants were required to rate the attractiveness of three types (original, masculine, feminine) of their own faces and the other participants' faces in same-sex and opposite-sex contexts. The results revealed that the participants rated their own faces as more attractive than other participants rated them regardless of the sexually dimorphic type (original, masculine, feminine) or the evaluation context. More importantly, the male and female participants showed different preferences for the three types of self-faces. Specifically, in the same-sex context, the female participants rated their own original faces as significantly more attractive than the masculine and feminine faces, and the male participants rated their own masculine faces as significantly more attractive than the feminine faces; while in the opposite-sex context, no significant difference among the attractiveness scores of the three types of self-faces was found in both the male and female participants. The present study provides empirical evidence of the influence of sexual dimorphism on the evaluation of the attractiveness of self-faces.

Androstadienone resulted in a rightward shift of women's preference for sexually dimorphic male faces across the continuum of femininity-masculinity

As a derivative of testosterone, androstadienone (AND) can influence human psychological and physiological states. To explore the influence of AND on women's preferences for male sexual dimorphic faces in a mate-choice context, we asked 52 females in the luteal phase to choose one from four sexual dimorphic male faces in a long-term and short-term context while inhaling 250 μm of AND or a placebo odor on two consecutive days. Results revealed that participants had a greater and lesser preference for the +30% masculinized and 60% feminized faces, respectively, while inhaling AND, as compared to when inhaling the placebo. The AND intervention resulted in a rightward shift of the women's preference for male sexual dimorphic faces across the continuum of femininity-masculinity. The current findings highlight that AND may influence women's preference for male sexually dimorphic faces in a mate-choice context.

Perceived attractiveness of Czech faces across 10 cultures: Associations with sexual shape dimorphism, averageness, fluctuating asymmetry, and eye color

Research on the perception of faces typically assumes that there are some universal values of attractiveness which are shared across individuals and cultures. The perception of attractiveness may, however, vary across cultures due to local differences in both facial morphology and standards of beauty. To examine cross-cultural consensus in the ratings of attractiveness, we presented a set of 120 non-manipulated photographs of Czech faces to ten samples of raters from both European (Czech Republic, Estonia, Sweden, Romania, Turkey, Portugal) and non-European countries (Brazil, India, Cameroon, Namibia). We examined the relative contribution of three facial markers (sexual shape dimorphism, averageness, fluctuating asymmetry) to the perception of attractiveness as well as the possible influence of eye color, which is a locally specific trait. In general, we found that both male and female faces which were closer to the average and more feminine in shape were regarded as more attractive, while fluctuating asymmetry had no effect. Despite a high cross-cultural consensus on attractiveness standards, significant differences in the perception of attractiveness seem to be related to the level of socio-economic development (as measured by the Human Development Index, HDI). Attractiveness ratings by raters from low-HDI countries (India, Cameroon, Namibia) converged less with ratings from Czech Republic than ratings from high-HDI countries (European countries and Brazil). With respect to eye color, some local patterns emerged which we discuss as a consequence of negative frequency-dependent selection.

Vocal Parameters of Speech and Singing Covary and Are Related to Vocal Attractiveness, Body Measures, and Sociosexuality: A Cross-Cultural Study

Perceived vocal attractiveness and measured sex-dimorphic vocal parameters are both associated with underlying individual qualities. Research tends to focus on speech but singing is another highly evolved communication system that has distinct and universal features with analogs in other species, and it is relevant in mating. Both speaking and singing voice provides relevant information about its producer. We tested whether speech and singing function as "backup signals" that indicate similar underlying qualities. Using a sample of 81 men and 86 women from Brazil and the Czech Republic, we investigated vocal attractiveness rated from speech and singing and its association with fundamental frequency (F0), apparent vocal tract length (VTL), body characteristics, and sociosexuality. F0, VTL, and rated attractiveness of singing and speaking voice strongly correlated within the same individual. Lower-pitched speech in men, higher-pitched speech and singing in women, individuals who like to sing more, and singing of individuals with a higher pitch modulation were perceived as more attractive. In men, physical size positively predicted speech and singing attractiveness. Male speech but not singing attractiveness was associated with higher sociosexuality. Lower-pitched male speech was related to higher sociosexuality, while lower-pitched male singing was linked to lower sociosexuality. Similarly, shorter speech VTL and longer singing VTL predicted higher sociosexuality in women. Different vocal displays function as "backup signals" cueing to attractiveness and body size, but their relation to sexual strategies in men and women differs. Both singing and speech may indicate evolutionarily relevant individual qualities shaped by sexual selection.

Romantic Love and Attentional Biases Toward Attractive Alternatives and Rivals: Long-Term Relationship Maintenance Among Female Chinese College Students

Studies about heterosexual individuals' long-term relationship maintenance have indicated that committed individuals possess evolved psychological mechanisms that help protect their ongoing romantic relationships against threats from attractive others during early stage attentional processing when mating-related motivation is activated. In this study, two experiments tested the relationship maintenance mechanism among committed female college students in the Chinese cultural context under different love priming conditions. Committed Chinese women displayed inattention to attractive alternatives in positive love-scenario priming (Study 1: 114 female undergraduates, age range = 18-26 years), subliminal semantic love priming (Study 2: 110 female undergraduates, age range = 18-25 years), and baseline conditions (Studies 1 and 2). Those with high levels of chronic jealousy showed significantly increased attention to and difficulty disengaging attention from attractive rivals when subliminally primed with love. This provides further evidence, from an Eastern cultural context, for the existence of attentional biases toward attractive alternatives and rivals in early stage attentional processes for relationship maintenance. This research also illustrates the important role of romantic love in maintaining long-term romantic relationships.

Do Single Men Smell and Look Different to Partnered Men?

Previous research indicates human body odor (BO) can signal kinship, sickness and genetic compatibility. Based on research indicating single males have higher testosterone levels than partnered males and that higher testosterone levels are associated with stronger smelling BO, the current study aimed to determine if, by extension of previous findings, single males’ BO smells stronger than partnered males’ BO. Eighty-two heterosexual women aged 18–35 years rated the BO and faces of six different males also aged 18–35 years. Consistent with the hypothesis, single men’s BO smelled stronger than partnered men’s BO and single men’s faces were rated as more masculine than partnered men’s faces. The possible advantages of females being able to identify single males are addressed in the Discussion.

The Influence of Body Composition Effects on Male Facial Masculinity and Attractiveness

Body mass index (BMI) and its facial correlates influence a range of perceptions including masculinity and attractiveness. BMI conflates body fat and muscle which are sexually dimorphic because men typically have more muscle but less fat than women. We therefore investigated the influence of facial correlates of body composition (fat mass and muscle mass) on the perception of masculinity in male faces. Women have been found to prefer more masculine looking men when considering short-term relationships compared with long-term relationships. We therefore conducted a second study of heterosexual women’s preferences for facial correlates of fat and muscle mass under long and short relationship contexts. We digitally transformed face shape simulating the effects of raised and lowered levels of body fat or muscle, controlling for each other, height and age. In Study 1, participants rated masculinity of shape-transformed male faces. The face shape correlates of muscle mass profoundly enhanced perceived masculinity but the face shape correlates of fat mass only affected the perception of masculinity in underweight to low normal weight men. In Study 2, we asked two groups of women to optimize male face images (by adjusting the shape correlates of fat and muscle) to most resemble someone they would prefer, either for a short-term sexual relationship or for a long-term relationship. The results were consistent across the two participant groups: women preferred the appearance of male faces associated with a higher muscle mass for short-term compared with long-term relationships. No difference was found in women’s preference for the face shape correlates of fat mass between the two relationship contexts. These findings suggest that the facial correlates of body fat and muscle have distinct impacts on the perception of male masculinity and on women’s preferences. The findings indicate that body composition needs to be taken into consideration in psychological studies involving body weight.

Sex estimation from skull base radiographs in a contemporary Colombian population

The aim is to study the sexual dimorphism of the base of the skull in radiographs of a bone collection of contemporary Colombian adults, with the intention of formulating discriminant functions capable of classifying sex in this population. The sample consisted of 115 skull base radiographs, (44 females and 71 males), which originated from the Colombian Human Skeletals Collection. Radiographs with good contrast were selected. Images of skulls with asymmetries and fractures were excluded. Five measures: Maximum cranial base length, Foramen magnum length, Maximum cranial breadth, Bizygomatic breadth, Foramen magnum breadth length, were preformed using ImageJ5 software ^®; an intra-observer error was determined using paired t-test. Statistical analysis showed a sexual dimorphism for all variables (p < 0.05). The step-by-step procedure of the discriminant function selected 2 variables from the 5 (Foramen magnum length and Bizygomatic breadth) and the precision was between 86.4% and 88.6% in the determination of sex. However cross-validation showed an accuracy of 85.7% to male and 87.2% to female. The skull base is highly dimorphic. The established discriminant functions can be used to estimate sex in the Colombian population.

Facial masculinity does not appear to be a condition-dependent male ornament and does not reflect MHC heterozygosity in humans

Recent studies have called into question the idea that facial masculinity is a condition-dependent male ornament that indicates immunocompetence in humans. We add to this growing body of research by calculating an objective measure of facial masculinity/femininity using 3D images in a large sample (n = 1,233) of people of European ancestry. We show that facial masculinity is positively correlated with adult height in both males and females. However, facial masculinity scales with growth similarly in males and females, suggesting that facial masculinity is not exclusively a male ornament, as male ornaments are typically more sensitive to growth in males compared with females. Additionally, we measured immunocompetence via heterozygosity at the major histocompatibility complex (MHC), a widely-used genetic marker of immunity. We show that, while height is positively correlated with MHC heterozygosity, facial masculinity is not. Thus, facial masculinity does not reflect immunocompetence measured by MHC heterozygosity in humans. Overall, we find no support for the idea that facial masculinity is a condition-dependent male ornament that has evolved to indicate immunocompetence.

No evidence that women using oral contraceptives have weaker preferences for masculine characteristics in men's faces

Previous research has suggested that women using oral contraceptives show weaker preferences for masculine men than do women not using oral contraceptives. Such research would be consistent with the hypothesis that steroid hormones influence women’s preferences for masculine men. Recent large-scale longitudinal studies, however, have found limited evidence linking steroid hormones to masculinity preferences. Given the relatively small samples used in previous studies investigating putative associations between masculinity preferences and oral contraceptive use, we compared the facial masculinity preferences of women using oral contraceptives and women not using oral contraceptives in a large online sample of 6482 heterosexual women. We found no evidence that women using oral contraceptives had weaker preferences for male facial masculinity than did women not using oral contraceptives. These findings add to a growing literature suggesting that links between reproductive hormones and preferences are more limited than previously proposed.

Does the interaction between partnership status and average progesterone level predict women's preferences for facial masculinity?

Many studies have attempted to identify biological factors that reliably predict individual differences in women's preferences for masculine male faces. Marcinkowska et al. (2018, Hormones & Behavior) recently reported that women's (N = 102) preferences for facial masculinity were predicted by the interaction between their relationship status (partnered versus unpartnered) and average progesterone level. Because previous findings for between-women differences in masculinity preferences have often not replicated well, we attempted to replicate Marcinkowska et al.'s result in an open data set from another recent study that had not tested this hypothesis (Jones et al., 2018, Psychological Science). In this sample of 316 women, we found that facial masculinity preferences were predicted by the interaction between women's relationship status and average progesterone level, consistent with Marcinkowska et al.'s results (data and analysis code are available at https://osf.io/q9szc). Together, these findings suggest that the combined effects of relationship status and average progesterone level may predict facial masculinity preferences relatively reliably.

The Relationship Between Observers' Self-Attractiveness and Preference for Physical Dimorphism: A Meta-Analysis

Background: Many studies have reported an association between observers' self-attractiveness and their preference for sexual dimorphism across different physical domains, including the face, voice, and body. However, the results of these studies are inconsistent. Here, a meta-analysis was conducted to estimate the association between observers' own attractiveness and their dimorphic preference.

Methods: Major electronic databases including PsycINFO, Web of Science, PubMed, ProQuest, and Google Scholar were searched during April 2017 (the first time) and April 2018 (the second time). The effect size computation and moderating effect analyses were conducted separately for masculine and feminine preferences.

Results: We identified 5,359 references, of which we included 25 studies (x = 55, x = number of the effect size) with 6,853 participants in the meta-analysis. Across these studies, the correlation between observers' own attractiveness and their sexual dimorphic preference was 0.095 (x = 55) and that for preference for masculinity (x = 39) and femininity (x = 16) were 0.102 and 0.076, respectively. The results of the funnel plot, Egger's regression method, and fail-safe number suggested that there was no obvious publication bias. The relationship depended on the relationship context (short or long-term), opposite or same sex (the gender of the observer and host), measures of observers' self-attractiveness (subject or objective), and preference task (e.g., attractiveness rating, forced-choice, and face sequence test). Furthermore, for female participants, using a hormonal contraceptive also influenced their masculinity preference. The effect size for the preference for a masculine body and voice was larger than that for facial masculinity.

Conclusion: We found a small but significant correlation between self-attractiveness and physical dimorphic preference, the relationship was moderated by the relationship context, same/opposite-sex, and contraceptive using. These three moderating effects represented the observer's trade-off on good genes, good provider and good father (3Gs) consistent with the life history strategies. Besides, measurement of observers' attractiveness, type of preference task and stimuli may also involve the relationship.

Judging Others by Your Own Standards: Attractiveness of Primate Faces as Seen by Human Respondents

The aspects of facial attractiveness have been widely studied, especially within the context of evolutionary psychology, which proposes that aesthetic judgements of human faces are shaped by biologically based standards of beauty reflecting the mate quality. However, the faces of primates, who are very similar to us yet still considered non-human, remain neglected. In this paper, we aimed to study the facial attractiveness of non-human primates as judged by human respondents. We asked 286 Czech respondents to score photos of 107 primate species according to their perceived "beauty." Then, we analyzed factors affecting the scores including morphology, colors, and human-likeness. We found that the three main primate groups were each scored using different cues. The proportions of inner facial features and distinctiveness are cues widely reported to affect human facial attractiveness. Interestingly, we found that these factors also affected the attractiveness scores of primate faces, but only within the Catarrhines, i.e., the primate group most similar to humans. Within this group, human-likeness positively affected the attractiveness scores, and facial extremities such as a prolonged nose or exaggerated cheeks were considered the least attractive. On the contrary, the least human-like prosimians were scored as the most attractive group. The results are discussed in the context of the "uncanny valley," the widely discussed empirical rule.

Ovulation, Sex Hormones, and Women's Mating Psychology

The dual mating strategy hypothesis proposes that women's preferences for uncommitted sexual relationships with men displaying putative fitness cues increase during the high-fertility phase of the menstrual cycle. Results consistent with this hypothesis are widely cited as evidence that sexual selection has shaped human mating psychology. However, the methods used in most of these studies have recently been extensively criticized. Here we discuss (i) new empirical studies that address these methodological problems and largely report null results and (ii) an alternative model of hormonal regulation of women's mating psychology that can better accommodate these new data.

Sex and Physiological Cycles Affect the Automatic Perception of Attractive Opposite-Sex Faces: A Visual Mismatch Negativity Study

Facial attractiveness plays important roles in social interaction. Electrophysiological and neuroimaging studies found several brain areas to be differentially responsive to attractive relative to unattractive faces. However, little is known about the time course of the information processing, especially under the unattended condition. Based on a "cross-modal delayed response" paradigm, the present study aimed to explore the automatic mechanism of facial attractiveness processing of females with different physiological cycles and males, respectively, through recording the event-related potentials in response to (un)attractive opposite-sex faces by two experiments. The attractiveness-related visual mismatch negativity (attractiveness vMMN) in posterior scalp distribution was recorded in both the experiments, which indicated that attractive faces could be processed automatically. And high-attractive opposite-sex faces can elicit larger vMMN in males than females in menstrual period in Study 1, but similar as females in ovulatory period in Study 2. Furthermore, by comparison, the latency of attractiveness vMMN in females with the ovulatory period was the longest. These results indicated as follows: (1) Males were more sensitive to attractive female faces, (2) females in ovulatory period were also attracted by the attractive male faces, (3) the long vMMN latency in females during ovulatory period suggested a special reproductive motivation to avoid being tainted by genes, which takes priority over the breeding motivation.