Menstrual cycle alters face preference

Some Evidence That Truth-Tellers Are More Attractive Than Liars

Despite the prevalence of deception, people rarely doubt others' sincerity. However, indirect evaluations of liars and truth-tellers may differ even in the absence of suspicion about veracity. Across three studies, we provide evidence for the truth attraction effect in two samples of target stimuli and three samples of participant judges. Target people are perceived as more attractive when telling the truth versus when they lie, an effect mediated by target warmth and openness. The truth attraction effect is stronger for female targets (vs. males); however, it is unaffected by the gender of the judge. Findings suggest people may be more likely to approach truth-tellers versus liars, even when not actively judging veracity. We discuss the challenges and benefits of treating both targets and participants as random factors in linear mixed-effect analyses and join the chorus of calls to increase the number of target stimuli in deception research.

Time perception of attractive male faces and voices: The role of women's menstrual cycle

Accurate time measurement is essential for organisms to synchronize their internal biological cycles with the external environment, crucial for reproductive success and survival. This study examines fluctuations in time perception across different phases of the menstrual cycle in response to visual and vocal attractiveness, building on previous research showing that women estimate longer viewing times for attractive male photos compared to unattractive ones. Forty-eight females participated in the experiment during both the menstruation and ovulation phases of their menstrual cycles, completing visual and auditory oddball tasks. Participants viewed a series of five stimuli and reproduced the duration of the last stimulus by pressing a mouse button. The final stimulus could be identical to the previous four (control trials), an attractive or unattractive male photo (visual attractiveness block), a masculinized or feminized male face (visual sexually dimorphic block), or a masculinized or feminized male voice (auditory sexually dimorphic block). Results indicated that duration estimates for masculinized male voices were significantly longer compared to feminized voices, while no differences were found for the menstruation phase. However, no differences were observed between the phases of the menstrual cycle in the visual conditions. Nevertheless, we replicate the temporal dilation effect associated with viewing attractive stimuli, suggesting an acceleration of the internal clock related to attractiveness perception. Our findings align with the literature on this phenomenon and provide initial evidence for an adaptive time perception mechanism influenced by the menstrual cycle, contributing to the understanding of the complex interactions between biological cycles and perceptual processes.

Modulation of strategic status signaling: oxytocin changes men's fluctuations of status products preferences in their female partners' menstrual cycle

RATIONALE

Women exhibit subtle fluctuations in mating-related behaviors throughout their menstrual cycle, and men are capable of detecting these ovulatory cues. This ability may impact male mating behavior, prompting adjustments in their preferences for consumer products based on these signals. Nonetheless, the potential influence of oxytocin on men's preferences for status products, particularly in the context of their female partners' menstrual cycles, is not yet known.

OBJECTIVES

This study aims to explore how oxytocin regulates men's responses to their female partners' ovulation in heterosexual romantic relationships by specifically examining changes in their preferences for status consumption.

METHODS

Through a pilot study (N = 110) and two main studies (N1 = 789, N2 = 120), we analyzed how oxytocin influences fluctuations in men's preferences for status products throughout their female partners' menstrual cycles. In Study 1, we examined the impact of the female menstrual cycle on men's preferences for status products. In Study 2, we employed intranasal oxytocin to investigate its modulatory effect on the menstrual cycle's influence.

RESULTS

Findings revealed that men demonstrated a lower preference for status products during their partners' ovulation compared to non-ovulatory phases. Furthermore, intranasal oxytocin significantly reduced men's liking for status products during the ovulatory phase, but not during the menstrual phase, with a stronger effect observed among men with a heightened intuitive inclination.

CONCLUSIONS

These results suggest that men in committed relationships strategically adapt their consumption of status products according to their female partners' menstrual cycles, with oxytocin playing a moderating role in this adaptation and individual differences influencing responses.

Assessing the association between menstrual cycle phase and voice-gender categorization: no robust evidence for an association

Introduction

Hormone fluctuations during the menstrual cycle are known to influence a wide variety of cognitive-emotional processes and behavior. Mate choice and changes in attractiveness ratings for faces and voices are often investigated in this context, but research on changes in voice-gender perception independent of attractiveness ratings is rare even though the voice is an essential element in social interactions. For this reason, we investigated the influence of cycle phase and levels of estrogen and progesterone on performance in a voice-gender categorization task. Our expectation was to find a more pronounced other-sex effect, so faster and more accurate reactions for masculine voices, in the follicular (fertile) phase than in the luteal phase.

Methods

We measured 65 healthy, naturally-cycling women, half of them in the follicular phase and the other half in the luteal phase. For the analyses, we used signal detection theory (SDT) measures in addition to reaction times and percent of correct reactions. The study was preregistered after measuring the first 33 participants and prior to any data analyses (https://osf.io/dteyn).

Results

Cycle phase and hormone levels showed no significant effect on reaction time or SDT measures. This was the case both using frequentist analyses and Bayesian statistics. Reaction time was influenced by voice-gender, with faster reactions for feminine voices compared to masculine voices in both cycle phases.

Discussion

Taken together, our results add to the increasing number of studies that do not find an interaction of menstrual cycle phase and reaction to gendered stimuli.

Testing the congruency hypothesis using meta-analysis: Are changes in oral contraceptive use correlated with partnered women's sexual satisfaction?

Based on claims that changes in women's hormone levels influence their mating psychology, the Congruency Hypothesis proposes that women in relationships who change their hormonal contraceptive use after meeting their partner will report lower sexual satisfaction with their partner than women who do not change their oral contraceptive use. However, findings from studies testing this hypothesis have reported mixed results. Consequently, we conducted a meta-analysis of published studies on this topic. For the thirteen effects sizes from studies using between-subjects designs, the pooled correlation between congruency and sexual satisfaction was not statistically significant (r = 0.04, p = .091) and a Robust Bayesian meta-analysis found that the null hypothesis was moderately favoured over the Congruency Hypothesis (BF10 = 0.123, i.e., BF01 = 8.13, r = 0.003). For the four effect sizes from studies using within-subjects designs, the pooled correlation between congruency and sexual satisfaction was statistically significant (r = 0.18, p = .001) and a Robust Bayesian meta-analysis found weak evidence in favour of the Congruency Hypothesis (BF10 = 1.55, r = 0.09). Although the effect of congruency on sexual satisfaction may be statistically significant in some analyses, across all analyses, results indicated that the magnitude of the congruency effect was small. Thus, we suggest that it is unlikely that changes in oral contraceptive use have a substantial (i.e., large) effect on women's sexual satisfaction on average. Still, some women might experience congruency effects and the overall evidence remains uncertain. More work, ideally in the form of randomized controlled trials, is needed to find a definite answer for research questions relying on the Congruency Hypothesis.

Mate assessment based on physical characteristics: a review and reflection

Mate choice, and sex differences in romantic behaviours, represented one of the first major applications of evolutionary biology to human behaviour. This paper reviews Darwinian approaches to heterosexual mate assessment based on physical characteristics, placing the literature in its historical context (1871-1979), before turning (predominantly) to psychological research on attractiveness judgements based on physical characteristics. Attractiveness is consistently inferred across multiple modalities, with biological theories explaining why we differentiate certain individuals, on average, from others. Simultaneously, it is a judgement that varies systematically in light of our own traits, environment, and experiences. Over 30 years of research has generated robust effects alongside reasons to be humble in our lack of understanding of the precise physiological mechanisms involved in mate assessment. This review concludes with three questions to focus attention in further research, and proposes that our romantic preferences still provide a critical window into the evolution of human sexuality.

Effects of testosterone on speech production and perception: Linking hormone levels in males to vocal cues and female voice attractiveness ratings

This study sets out to investigate the potential effect of males' testosterone level on speech production and speech perception. Regarding speech production, we investigate intra- and inter-individual variation in mean fundamental frequency (fo) and formant frequencies and highlight the potential interacting effect of another hormone, i.e. cortisol. In addition, we investigate the influence of different speech materials on the relationship between testosterone and speech production. Regarding speech perception, we investigate the potential effect of individual differences in males' testosterone level on ratings of attractiveness of female voices. In the production study, data is gathered from 30 healthy adult males ranging from 19 to 27 years (mean age: 22.4, SD: 2.2) who recorded their voices and provided saliva samples at 9 am, 12 noon and 3 pm on a single day. Speech material consists of sustained vowels, counting, read speech and a free description of pictures. Biological measures comprise speakers' height, grip strength, and hormone levels (testosterone and cortisol). In the perception study, participants were asked to rate the attractiveness of female voice stimuli (sentence stimulus, same-speaker pairs) that were manipulated in three steps regarding mean fo and formant frequencies. Regarding speech production, our results show that testosterone affected mean fo (but not formants) both within and between speakers. This relationship was weakened in speakers with high cortisol levels and depended on the speech material. Regarding speech perception, we found female stimuli with higher mean fo and formants to be rated as sounding more attractive than stimuli with lower mean fo and formants. Moreover, listeners with low testosterone showed an increased sensitivity to vocal cues of female attractiveness. While our results of the production study support earlier findings of a relationship between testosterone and mean fo in males (which is mediated by cortisol), they also highlight the relevance of the speech material: The effect of testosterone was strongest in sustained vowels, potentially due to a strengthened effect of hormones on physiologically strongly influenced tasks such as sustained vowels in contrast to more free speech tasks such as a picture description. The perception study is the first to show an effect of males' testosterone level on female attractiveness ratings using voice stimuli.

Combined estrogen-progestin oral contraceptives and female sexuality: an updated review

INTRODUCTION

Sexual side effects of combined oral contraceptives (COCs) have not been fully understood, but increasing evidence prompts broader risk/benefit evaluation and merits inclusion in counseling on contraceptive options.

OBJECTIVES

The study sought to explore the impact of combined estrogens-progestin oral contraceptives on components of female sexuality, including sexual desire, anatomic genitourinary changes, lubrication, orgasm, provoked vestibulodynia, well-being, body image, partner preference, and relationship stability.

METHODS

A literature review was performed between April 2023 and January 2024 exploring the association between combined oral contraceptive pills and sexual health.

RESULTS

Although COCs decrease free testosterone, it is unclear if COCs affect sexual function, including desire. Antiandrogenic COCs do seem to have a negative effect on sexual arousal, lubrication, and orgasm. Provoked vestibulodynia may be related to early onset of COC use, low-estrogen pills, and antiandrogenic progestins. Emotional and sexual side effects are strong predictors of COC discontinuation. Longitudinal data indicate that using COCs when meeting and selecting a partner has implications on sexual satisfaction and relationship length. Analysis of data is complicated by various doses and forms of estrogen and progestin in COCs, which have changed over time.

CONCLUSION

Lack of randomized placebo-controlled studies and heterogenicity in study design hampers generalized statements about the effects of COCs on sexual function. Despite these challenges, consideration of sexual dysfunction when presenting and prescribing hormonal contraception is essential for informed consent, shared decision making, and ensuring reliable contraceptive choices.

Re-evaluating the Role of Partnership-Related Perceptions in Women's Preferences for Men with Masculine Face Shapes

Many researchers have proposed that women perceive men with masculine face shapes to be less suitable as parents and long-term partners than men with feminine face shapes, causing women to find masculine men more attractive for short-term than long-term relationships. However, recent work shows that results obtained using the type of experimentally manipulated stimuli that were employed in studies presenting evidence for these claims are not necessarily observed when natural (i.e., unmanipulated) face stimuli were used to suggest that the evidence for these claims may need to be revaluated. Consequently, we tested for possible relationships between ratings of natural male faces for parenting- and relationship-related traits and shape masculinity (Study 1) and also tested whether women's preferences for shape masculinity were stronger when natural male faces were rated for short-term relationships than when natural male faces were rated for long-term relationships (Studies 2 and 3). We saw no evidence for either of these predictions, instead finding that men with more attractive faces were perceived to be better parents and better long-term partners. Thus, our findings do not support the widely held view that masculine men are more attractive for short-term relationships because they are perceived to be unlikely to invest time and effort in their romantic partners and offspring.

Chronic and immediate refined carbohydrate consumption and facial attractiveness

The Western diet has undergone a massive switch since the second half of the 20th century, with the massive increase of the consumption of refined carbohydrate associated with many adverse health effects. The physiological mechanisms linked to this consumption, such as hyperglycaemia and hyperinsulinemia, may impact non medical traits such as facial attractiveness. To explore this issue, the relationship between facial attractiveness and immediate and chronic refined carbohydrate consumption estimated by glycemic load was studied for 104 French subjects. Facial attractiveness was assessed by opposite sex raters using pictures taken two hours after a controlled breakfast. Chronic consumption was assessed considering three high glycemic risk meals: breakfast, afternoon snacking and between-meal snacking. Immediate consumption of a high glycemic breakfast decreased facial attractiveness for men and women while controlling for several control variables, including energy intake. Chronic refined carbohydrate consumption had different effects on attractiveness depending on the meal and/or the sex. Chronic refined carbohydrate consumption, estimated by the glycemic load, during the three studied meals reduced attractiveness, while a high energy intake increased it. Nevertheless, the effect was reversed for men concerning the afternoon snack, for which a high energy intake reduced attractiveness and a high glycemic load increased it. These effects were maintained when potential confounders for facial attractiveness were controlled such as age, age departure from actual age, masculinity/femininity (perceived and measured), BMI, physical activity, parental home ownership, smoking, couple status, hormonal contraceptive use (for women), and facial hairiness (for men). Results were possibly mediated by an increase in age appearance for women and a decrease in perceived masculinity for men. The physiological differences between the three meals studied and the interpretation of the results from an adaptive/maladaptive point of view in relation to our new dietary environment are discussed.

Tendencies Toward Supernormality/Subnormality in Generating Attractive and Unattractive Female and Male Avatars: Gender Differences

In the present study, we investigated the differences in the experience of attractiveness and unattractiveness of human bodies. A total of 101 participants (55 females) were asked to create the most attractive and the most unattractive female and male figures using a computer animation. They performed this task by adjusting the size of six body parts: shoulders, breasts/chest, waist, hips, buttocks, and legs. Analyses indicated that attractive body parts were distributed normally with the peak shifted to moderately supernormal sizes, while unattractive body parts had mostly U-shaped or skewed distributions with extremes in super-supernormal and/or subnormal sizes. Generally, both male and female attractive bodies had prominent "sporty" look: supernormally wide shoulders and long legs. Gender differences showed that men prefer more supernomal masculine and feminine sizes, while women show an ambivalence toward both groups of traits. Principal components analysis revealed gender differences on the multitrait level: males focus on prominent masculine and feminine traits, while women focus on traits that make both male and female bodies more elongated and slender. Gender differences were in line with specific male and female positions in the partner selection process, while a certain tendency toward masculinization of the female body required the inclusion of social factors, such as the influence of the culture of a sporty and fit look.

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.

Sex and estrous cycle affect experience-dependent plasticity in mouse primary visual cortex

Sex hormones can affect cellular physiology and modulate synaptic plasticity, but it is not always clear whether or how sex-dependent differences identified in vitro express themselves as functional dimorphisms in the brain. Historically, most experimental neuroscience has been conducted using only male animals and the literature is largely mute about whether including female mice in will introduce variability due to inherent sex differences or endogenous estrous cycles. Though this is beginning to change following an NIH directive that sex should be included as a factor in vertebrate research, the lack of information raises practical issues around how to design experimental controls and apply existing knowledge to more heterogeneous populations. Various lines of research suggest that visual processing can be affected by sex and estrous cycle stage. For these reasons, we performed a series of in vivo electrophysiological experiments to characterize baseline visual function and experience-dependent plasticity in the primary visual cortex (V1) of male and female mice. We find that sex and estrous stage have no statistically significant effect on baseline acuity measurements, but that both sex and estrous stage have can modulate two mechanistically distinct forms of experience dependent cortical plasticity. We also demonstrate that resulting variability can be largely controlled with appropriate normalizations. These findings suggest that V1 plasticity can be used for mechanistic studies focusing on how sex hormones effect experience dependent plasticity in the mammalian cortex.

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.

Women's Estrus and Extended Sexuality: Reflections on Empirical Patterns and Fundamental Theoretical Issues

How do women's sexual interests change across their ovulatory cycles? This question is one of the most enduring within the human evolutionary behavioral sciences. Yet definitive, agreed-upon answers remain elusive. One empirical pattern appears to be robust: Women experience greater levels of sexual desire and interest when conceptive during their cycles. But this pattern is not straightforward or self-explanatory. We lay out multiple possible, broad explanations for it. Based on selectionist reasoning, we argue that the conditions that give rise to sexual interests during conceptive and non-conceptive phases are likely to differ. Because conceptive and non-conceptive sex have distinct functions, the sexual interests during conceptive and non-conceptive phases are likely to have different strategic ends. We discuss provisional evidence consistent with this perspective. But the exact nature of women's dual sexuality, if it exists, remains unclear. Additional empirical research is needed. But perhaps more crucially, this topic demands additional theory that fruitfully guides and interprets future empirical research.

Current Perspectives on Kisspeptins Role in Behaviour

The neuropeptide kisspeptin is now well-established as the master regulator of the mammalian reproductive axis. Beyond the hypothalamus, kisspeptin and its cognate receptor are also extensively distributed in extra-hypothalamic brain regions. An expanding pool of animal and human data demonstrates that kisspeptin sits within an extensive neuroanatomical and functional framework through which it can integrate a range of internal and external cues with appropriate neuroendocrine and behavioural responses. In keeping with this, recent studies reveal wide-reaching effects of kisspeptin on key behaviours such as olfactory-mediated partner preference, sexual motivation, copulatory behaviour, bonding, mood, and emotions. In this review, we provide a comprehensive update on the current animal and human literature highlighting the far-reaching behaviour and mood-altering roles of kisspeptin. A comprehensive understanding of this important area in kisspeptin biology is key to the escalating development of kisspeptin-based therapies for common reproductive and related psychological and psychosexual disorders.

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.

Associations of observer's gender, Body Mass Index and internalization of societal beauty ideals to visual body processing

We examined whether visual processing mechanisms of the body of conspecifics are different in women and men and whether these rely on westernised socio-cultural ideals and body image concerns. Twenty-four women and 24 men performed a visual discrimination task of upright or inverted images of female or male bodies and faces (Experiment 1) and objects (Experiment 2). In Experiment 1, both groups of women and men showed comparable abilities in the discrimination of upright and inverted bodies and faces. However, the gender of the human stimuli yielded different effects on participants' performance, so that female faces, and male bodies appeared to be processed less configurally than female bodies and male faces, respectively. Interestingly, the reduction of configural processing for male bodies was significantly predicted by participants' Body Mass Index (BMI) and their level of internalization of muscularity. Our findings suggest that configural visual processing of bodies and faces in women and men may be linked to a selective attention to detail needed for discriminating salient physical (perhaps sexual) cues of conspecifics. Importantly, BMI and muscularity internalization of beauty ideals may also play a crucial role in this mechanism.

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.

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.

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We modeled individual preferences for attractive faces in two cultures

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Attractive face features differ from the face average and sexual dimorphism

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Instead, culture and individual preferences shape attractive face features

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

Was facial width-to-height ratio subject to sexual selection pressures? A life course approach

Sexual selection researchers have traditionally focused on adult sex differences; however, the schedule and pattern of sex-specific ontogeny can provide insights unobtainable from an exclusive focus on adults. Recently, it has been debated whether facial width-to-height ratio (fWHR; bi-zygomatic breadth divided by midface height) is a human secondary sexual characteristic (SSC). Here, we review current evidence, then address this debate using ontogenetic evidence, which has been under-explored in fWHR research. Facial measurements were collected from 3D surface images of males and females aged 3 to 40 (Study 1; US European-descent, n = 2449), and from 2D photographs of males and females aged 7 to 21 (Study 2; Bolivian Tsimane, n = 179), which were used to calculate three fWHR variants (which we call fWHRnasion, fWHRstomion, and fWHRbrow) and two other common facial masculinity ratios (facial width-to-lower-face-height ratio, fWHRlower, and cheekbone prominence). We test whether the observed pattern of facial development exhibits patterns indicative of SSCs, i.e., differential adolescent growth in either male or female facial morphology leading to an adult sex difference. Results showed that only fWHRlower exhibited both adult sex differences as well as the classic pattern of ontogeny for SSCs-greater lower-face growth in male adolescents relative to females. fWHRbrow was significantly wider among both pre- and post-pubertal males in the Bolivian Tsimane sample; post-hoc analyses revealed that the effect was driven by large sex differences in brow height, with females having higher placed brows than males across ages. In both samples, all fWHR measures were inversely associated with age; that is, human facial growth is characterized by greater relative elongation in the mid-face and lower face relative to facial width. This trend continues even into middle adulthood. BMI was also a positive predictor of most of the ratios across ages, with greater BMI associated with wider faces. Researchers collecting data on fWHR should target fWHRlower and fWHRbrow and should control for both age and BMI. Researchers should also compare ratio approaches with multivariate techniques, such as geometric morphometrics, to examine whether the latter have greater utility for understanding the evolution of facial sexual dimorphism.

Does Self-rated Attractiveness Predict Women’s Preferences for Facial Masculinity? Data From an Arab Sample

Objectives

Because more attractive women may be better able to attract and/or retain masculine mates, many researchers have proposed that women who consider themselves to be more physically attractive will show stronger preferences for men displaying masculine facial characteristics. Empirical evidence for this putative association between women’s self-rated attractiveness and preference for facial masculinity has come almost entirely from studies of Western women. Thus, we investigated whether this pattern of results also occurs in a sample of non-Western women.

Methods

We investigated the relationship between self-rated attractiveness and facial-masculinity preferences in a sample of Arab women (N = 281). Facial-masculinity preferences were assessed from attractiveness judgments of masculinized versus feminized versions of face images.

Results

By contrast with previous findings for Western women’s self-rated attractiveness, we observed no compelling evidence that Arab women who considered themselves to be more attractive showed stronger preferences for masculine men.

Conclusions

Our results suggest that previously reported associations between self-rated attractiveness and masculinity preferences might be somewhat culture specific, potentially reflecting cultural differences in typical mating strategies.

Facial shape affects self-perceived facial attractiveness

Facial appearance expresses numerous cues about physical qualities as well as psychosocial and personality traits. Attractive faces are recognized clearly when seen and are often viewed advantageously in professional, social and romantic relationships. On the other hand, self-perceived attractiveness is not well understood and has been mainly attributed to psychological and cognitive factors. Here we use 3-dimensional facial surface data of a large young adult population (n = 601) to thoroughly assess the effect of facial shape on self-perceived facial attractiveness. Our results show that facial shape had a measurable effect on self-perception of facial attractiveness in both sexes. In females, self-perceived facial attractiveness was linked to decreased facial width, fuller anterior part of the lower facial third and more pronounced middle forehead and root of the nose. Males favored a well-defined chin, flatter cheeks and zygomas, and more pronounced eyebrow ridges, nose and middle forehead. The findings of this study support the notion that self-perceived facial attractiveness is not only motivated by psychological traits, but objectively measured phenotypic traits also contribute significantly. The role of social stereotypes for facial attractiveness in modern society is also inferred and discussed.

A longitudinal evaluation of ovulatory cycle shifts in women's mate attraction and preferences

Are ovulatory cycle shifts in women's mate attraction and preferences robust? What are underlying mechanisms of potential cycle shifts? These questions are the subject of a current scientific debate surrounding the good genes ovulatory shift hypothesis. Here, we report a large, preregistered, within-subjects study, including salivary hormone measures and conception risk estimates based on luteinizing hormone tests. In four sessions across one ovulatory cycle, N = 257 women (= 1028 sessions) rated the attractiveness of 40 natural male bodies, 40 natural female bodies and 40 objects. Multilevel analyses yielded weak evidence for ovulatory increases in women's general attraction, specifically to male bodies, though they are not systematically related to changes in steroid hormone levels. Further, we found no compelling robust evidence for mate preference shifts across the cycle, as only one out of many different tests showed some weak evidence for such effects. Mechanisms regulating cycle shifts, the impact of our results on developing and revising cycle shift theories, and influences of different methodologies on results are discussed.

Environmental convergence in facial preferences: a cross-group comparison of Asian Vietnamese, Czech Vietnamese, and Czechs

It has been demonstrated that sociocultural environment has a significant impact on human behavior. This contribution focuses on differences in the perception of attractiveness of European (Czech) faces as rated by Czechs of European origin, Vietnamese persons living in the Czech Republic and Vietnamese who permanently reside in Vietnam. We investigated whether attractiveness judgments and preferences for facial sex-typicality and averageness in Vietnamese who grew up and live in the Czech Republic are closer to the judgements and preferences of Czech Europeans or to those of Vietnamese born and residing in Vietnam. We examined the relative contribution of sexual shape dimorphism and averageness to the perception of facial attractiveness across all three groups of raters. Czech Europeans, Czech Vietnamese, and Asian Vietnamese raters of both sexes rated facial portraits of 100 Czech European participants (50 women and 50 men, standardized, non-manipulated) for attractiveness. Taking Czech European ratings as a standard for Czech facial attractiveness, we showed that Czech Vietnamese assessments of attractiveness were closer to this standard than assessments by the Asian Vietnamese. Among all groups of raters, facial averageness positively correlated with perceived attractiveness, which is consistent with the "average is attractive" hypothesis. A marginal impact of sexual shape dimorphism on attractiveness rating was found only in Czech European male raters: neither Czech Vietnamese nor Asian Vietnamese raters of either sex utilized traits associated with sexual shape dimorphism as a cue of attractiveness. We thus conclude that Vietnamese people permanently living in the Czech Republic converge with Czechs of Czech origin in perceptions of facial attractiveness and that this population adopted some but not all Czech standards of beauty.

Balancing costs and benefits in primates: ecological and palaeoanthropological views

Maintaining the balance between costs and benefits is challenging for species living in complex and dynamic socio-ecological environments, such as primates, but also crucial for shaping life history, reproductive and feeding strategies. Indeed, individuals must decide to invest time and energy to obtain food, services and partners, with little direct feedback on the success of their investments. Whereas decision-making relies heavily upon cognition in humans, the extent to which it also involves cognition in other species, based on their environmental constraints, has remained a challenging question. Building mental representations relating behaviours and their long-term outcome could be critical for other primates, but there are actually very little data relating cognition to real socio-ecological challenges in extant and extinct primates. Here, we review available data illustrating how specific cognitive processes enable(d) modern primates and extinct hominins to manage multiple resources (e.g. food, partners) and to organize their behaviour in space and time, both at the individual and at the group level. We particularly focus on how they overcome fluctuating and competing demands, and select courses of action corresponding to the best possible packages of potential costs and benefits in reproductive and foraging contexts. This article is part of the theme issue 'Existence and prevalence of economic behaviours among non-human primates'.

Mapping changes in women's visual functions during the menstrual cycle: narrative review

BACKGROUND

This article systematically updates the literature on changes in visual functions during the phases of the normal menstrual cycle in women.

OBJECTIVES

To update Guttridge's 1994 review of visual structures and functions associated with the menstrual cycle and broaden the search through psychophysical, neuroimaging and neurobehavioral measurements covering 1994-2020.

DESIGN AND SETTING

Narrative review conducted in a neurosciences and behavior laboratory in Brazil.

METHODS

The PubMed, Cochrane Clinical Answers and Google Scholar databases were searched. After screening and applying the eligibility criteria, 32 articles were examined. Through this analysis, the following information was extracted: (1) geographical distribution of the study; (2) sample size (according to age and phase of the menstrual cycle); (3) type of measurements according to psychophysical, neuroimaging and neurobehavioral instruments; (4) vision testing model; (5) visual subcategory evaluated; (6) categories of processed visual stimuli; and (7) main findings.

RESULTS

The menstrual phases give rise to significant changes in visual functions, including in relation to orientation and spatial attention, visual campimetry and visual sensitivity. These relate specifically to the follicular and luteal phases.

CONCLUSIONS

These findings theoretically expand the effects of menstrual cycles on visual functions found by Guttridge (1994). Despite some inconsistencies in the studies analyzed, it was found that visual processing during the follicular and luteal phases of the normal menstrual cycle of healthy women can explain physiological, cognitive, behavioral and social modulations.

Social Orientation in the Luteal Phase: Increased Social Feedback Sensitivity, Inhibitory Response, Interpersonal Anxiety and Cooperation Preference

Cyclical fluctuations of the ovarian hormones estrogen (E2) and progesterone (PROG) have multiple effects on reproduction and development. However, little is known about the roles of E2 and PROG in women's social behaviors. Here, based on evolutionary theory suggesting social sensitivity and inhibition ability are conductive to maintaining social relationships, we provide evidence for the association between menstrual phases and social orientation. In Study 1, 78 women provided saliva samples and reported their intensity of behavioral activation/inhibition system (BAS/BIS) and interpersonal sensitivity at either of two phases of the menstrual cycle: late follicular phase (FP), and mid-luteal phase (LP). A significant between-subject association emerged, revealing that women with higher PROG levels reported higher levels of social feedback sensitivity, and women with relatively high PROG levels showed a positive association between their E2 levels and inhibitory response. In Study 2, 30 women reported their interpersonal anxiety and finished the social value orientation (SVO) measures at both late FP and mid-LP. A significant within-person effect emerged: women in the mid-LP, which is characterized by higher PROG levels, reported higher levels of interpersonal anxiety and SVO. In sum, these findings revealed that women's social orientation could fluctuate naturally with ovarian hormones across the menstrual cycle.

The Dyadic Effects of Top/Bottom Sexual Self-Labels and Partner Sexual Role Requirements on Facial Masculinity Preferences Among Gay and Bisexual Men in China

Sexual position preferences in male same-sex relationships are reflected in individuals' top/bottom sexual self-labels and requirements for their partners' sexual positions. Previous studies revealed significant differences in facial masculinity preferences among sexual self-label groups among gay and bisexual men. This study examined the moderating effect of requirements for partners' sexual positions on the relationship between facial masculinity preferences and sexual self-labels. Participants (N = 1,628, data were collected in 2019) were shown 10 pairs of male faces sequentially, with each pair consisting of a masculinized and feminized version of the same base face. "Bottoms" and "versatiles" preferred masculinized faces over feminized faces, whereas "tops" showed no significant preference for masculinized or feminized faces. "Tops" preferred more feminized faces than did "bottoms" and "versatiles." There were significant interactions between sexual self-labels and requirements for partners' positions. "Tops" who required a complementary partner preferred more feminized faces than did those having no requirement. "Bottoms" who required a complementary partner preferred more masculinized faces than did those having no requirement. "Versatiles" requiring a "top" as a romantic partner preferred more masculinized faces than did those requiring "bottoms" or those having no requirement. The findings highlighted the correlation between sexual preferences and partner choices among gay and bisexual men. Stereotypes about gender and masculinity may account for the links between sexual self-labels and partner choice in both sexual self-labeling and preferred labeling of partners based on masculinity.

Menstrual Cycle Variations in Gray Matter Volume, White Matter Volume and Functional Connectivity: Critical Impact on Parietal Lobe

The role of gonadal hormones in neural plasticity remains unclear. This study aimed to examine the effects of naturally fluctuating hormone levels over the menstrual cycle in healthy females. Gray matter, functional connectivity (FC) and white matter changes over the cycle were assessed by using functional magnetic resonance imaging (fMRI), resting state fMRI, and structural MRIs, respectively, and associated with serum gonadal hormone levels. Moreover, electrocutaneous sensitivity was evaluated in 14 women in four phases of their menstrual cycle (menstrual, follicular, ovulatory, and luteal). Electrocutaneous sensitivity was greater during follicular compared to menstrual phase. Additionally, pain unpleasantness was lower in follicular phase than other phases while pain intensity ratings did not change over the cycle. Significant variations in cycle phase effects on gray matter volume were found in the left inferior parietal lobule (IPL) using voxel-based morphometry. Subsequent Freesurfer analysis revealed greater thickness of left IPL during the menstrual phase when compared to other phases. Also, white matter volume fluctuated across phases in left IPL. Blood estradiol was positively correlated with white matter volume both in left parietal cortex and whole cortex. Seed-driven FC between left IPL and right secondary visual cortex was enhanced during ovulatory phase. A seed placed in right IPL revealed enhanced FC between left and right IPL during the ovulatory phase. Additionally, we found that somatosensory cortical gray matter was thinner during follicular compared to menstrual phase. We discuss these results in the context of likely evolutionary pressures selecting for enhanced perceptual sensitivity across modalities specifically during ovulation.

Reproductive hormone measurement from minimally invasive sample types: Methodological considerations and anthropological importance

Energetic investment in human reproduction has long been recognized as costly, influencing developmental, physiological, and behavioral patterns in males and females. These effects are largely coordinated through the actions of reproductive hormones (eg, testosterone, estradiol, and progesterone). Here, the utility and limitations of minimally invasive sampling techniques are explored, providing a novel perspective on how reproductive hormone measurements can enhance reproductive endocrinology research. Salivary steroid measures are most commonly used, although several dried blood spot and urine assays are also available, and researchers continue to explore the efficacy of other sample types. These relatively simple measures have facilitated the collection of multiple samples from a single participant, allowing researchers to more accurately track the diurnal and cyclical variation exhibited by many reproductive hormones. Ultimately, the ability to collect fine-grained participant data allows biological anthropologists to better test questions central to human reproductive ecology, life history theory, and public health. For example, fieldwork using these techniques suggests that testosterone profile variation across populations is influenced by energetic constraints and reproductive status. Moreover, hormone concentrations shape the development of sex characteristics, with implications for evolutionary questions related to sexual selection. Hormone levels also can be used to identify a range of medical concerns (eg, suppressed hormone production levels linked with psychosocial stress). These findings highlight how minimally invasive collection techniques can be applied to test diverse evolutionary hypotheses and identify important health concerns. Still, more work is needed to standardize collection and laboratory analysis procedures, thereby enabling more direct data comparisons between researchers.

A new data-driven mathematical model dissociates attractiveness from sexual dimorphism of human faces

Human facial attractiveness is evaluated by using multiple cues. Among others, sexual dimorphism (i.e. masculinity for male faces/femininity for female faces) is an influential factor of perceived attractiveness. Since facial attractiveness is judged by incorporating sexually dimorphic traits as well as other cues, it is theoretically possible to dissociate sexual dimorphism from facial attractiveness. This study tested this by using a data-driven mathematical modelling approach. We first analysed the correlation between perceived masculinity/femininity and attractiveness ratings for 400 computer-generated male and female faces (Experiment 1) and found positive correlations between perceived femininity and attractiveness for both male and female faces. Using these results, we manipulated a set of faces along the attractiveness dimension while controlling for sexual dimorphism by orthogonalisation with data-driven mathematical models (Experiment 2). Our results revealed that perceived attractiveness and sexual dimorphism are dissociable, suggesting that there are as yet unidentified facial cues other than sexual dimorphism that contribute to facial attractiveness. Future studies can investigate the true preference of sexual dimorphism or the genuine effects of attractiveness by using well-controlled facial stimuli like those that this study generated. The findings will be of benefit to the further understanding of what makes a face attractive.

Facial Masculinity Increases Perceptions of Men’s Age, But Not Perceptions of Their Health: Data From an Arab Sample

Masculine characteristics in men’s faces are often assumed to function as health cues. However, evidence for this assumption from empirical tests is mixed. For example, research on Western women’s face perceptions found that masculinized versions of men’s faces were perceived to be older, but not healthier, than feminized versions. Since research on this topic has focused on Western women’s face perceptions, we investigated the effects of masculinizing face images on Arab women’s perceptions of men’s health (study 1, N = 211) and age (study 2, N = 209). Arab women perceived masculinized versions of male face images to be older, but not healthier, than feminized versions. These results add to a growing body of evidence challenging the assumption that male facial masculinity functions primarily as a health cue.

Can Physical and/or Sexual Abuse Play a Role in the Female Choice of a Partner? A Cross-Sectional, Correlational Pilot Study

The present study aims to evaluate the relationship in women between a history of physical/sexual abuse and the preferences regarding the choice of a partner for a short/long-term relationship in terms of male facial dimorphism, and to assess their sexual functioning. We enrolled 48 abused women and 60 non-abused women. Facial preferences were evaluated with the Morphing test. Sexual functioning was measured with the Female Sexual Function Index (FSFI). Regarding the choice for a short-term partner, abused and non-abused women did not show any differences, and both groups chose a less masculine male face. On the other hand, regarding the choice for a long-term partner, abused women showed a preference for an average male face, whilst non-abused women preferred a less masculine face. The sexual functioning of abused women was found significantly dysfunctional in all domains of the FSFI. These data, generated from a small but highly selected cohort, demonstrated that physical/sexual abuse may be associated with a more rational and conscious choice of a male partner for a long-term relationship, but not with an instinctive one, as the choice of an occasional partner. In addition, the sexual functioning of abused women appears to be compromised by the traumatic experience.

Giving Guys Get the Girls: Men Appear More Desirable to the Opposite Sex When Displaying Costly Donations to the Homeless

One of the evolutionary adaptive benefits of altruism may be that it acts as an honest (reliable) signal of men’s mate quality. In this study, 285 female participants were shown one of three video scenarios in which a male target took £30 out of a cash machine (ATM) and gave either a lot (£30), a little (£1), or nothing to a homeless man. The participants rated the male target on his attractiveness, their short- and long-term mate preferences towards him, and the degree to which they thought he was likely to possess various parenting qualities. The results showed that, regardless of whether the man was described as rich or poor, participants rated him as being more attractive when he donated money, but only when the donation was costly (£30). In addition, altruism was shown to be important in long-term, but not short-term mate choice, and displays of altruism were associated with positive parenting qualities. It is argued that displays of altruism act as a reliable (honest) mate signal for a potential long-term parental partner.

Ideals of Facial Beauty Amongst the Chinese Population: Results from a Large National Survey

Surgical and non-surgical aesthetic treatments are very popular throughout Asia and in particular in China. With the globalisation and immigration of Chinese people to other countries where many seek treatment from Western-trained doctors, it is important to understand the ideals of beauty amongst Chinese people so as to achieve optimal results. We conducted an online survey to understand the preference of Han Chinese laypersons for facial shape, profile (straight, convex, concave), jaw angle and shape, and shape of the chin, nose, and lips. In addition, the participants were asked about their educational level, geographic location, likelihood to have cosmetic surgery, preference for surgical or non-surgical cosmetic procedures and whether ''being beautiful'' would affect their daily life. A total of 1417 responses were collected from 599 male and 818 female participants, the majority of them who were 25-35 years old (58.93%). The responses showed that the majority of participants preferred an oval face shape, with a smoothly tapered jaw angle for both men and women, round and pointy chin for both genders, straight to concave nose profile and full lips with well-defined cupid's bow. Most responders indicated they were not willing to undergo cosmetic surgery; however, when given a choice between surgical and non-surgical cosmetic procedures, 82.22% of the participants preferred non-surgical procedures. The majority of respondents (83%) thought that being beautiful has an effect on daily life and improves quality of life.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 .

Women’s Preferences for Sexual Dimorphism in Faces: Data from a Sample of Arab Women

Many previous studies have investigated the effects of manipulating sexually dimorphic shape characteristics in face images on attractiveness judgments. However, results have been mixed and show considerable cross-cultural variability, particularly for women’s judgments of men’s facial attractiveness. Because very little research has investigated face preferences in Arab samples, we assessed Arab women’s preferences for sexually dimorphic face shapes (study 1) and the effect of sexually dimorphic face shapes on Arab women’s dominance perceptions (study 2). Analyses showed that Arab women preferred feminized versions of both women’s and men’s faces over masculinized versions (study 1, N = 272) and that masculinizing face shape had a positive effect on Arab women’s perceptions of the dominance of men, but not women (study 2, N = 270). These image manipulations did not have a significant effect on perceptions of trustworthiness, however (study 3, N = 434). Collectively, these results suggest that Arab women prefer relatively feminine face shapes in potential mates that they perceive as being low dominance. We discuss some directions for future research on the ultimate function of Arab women’s preferences for sexual dimorphism in faces

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.