Menstrual cycle alters face preference

Sex differences in adults' relative visual interest in female and male faces, toys, and play styles

An individual's reproductive potential appears to influence response to attractive faces of the opposite sex. Otherwise, relatively little is known about the characteristics of the adult observer that may influence his or her affective evaluation of male and female faces. An untested hypothesis (based on the proposed role of attractive faces in mate selection) is that most women would show greater interest in male faces whereas most men would show greater interest in female faces. Further, evidence from individuals with preferences for same-sex sexual partners suggests that response to attractive male and female faces may be influenced by gender-linked play preferences. To test these hypotheses, visual attention directed to sex-linked stimuli (faces, toys, play styles) was measured in 39 men and 44 women using eye tracking technology. Consistent with our predictions, men directed greater visual attention to all male-typical stimuli and visual attention to male and female faces was associated with visual attention to gender conforming or nonconforming stimuli in a manner consistent with previous research on sexual orientation. In contrast, women showed a visual preference for female-typical toys, but no visual preference for male faces or female-typical play styles. These findings indicate that sex differences in visual processing extend beyond stimuli associated with adult sexual behavior. We speculate that sex differences in visual processing are a component of the expression of gender phenotypes across the lifespan that may reflect sex differences in the motivational properties of gender-linked stimuli.

Sexual dimorphism of male face shape, partnership status and the temporal context of relationship sought modulate women's preferences for direct gaze

Most previous studies of face preferences have investigated the physical cues that influence face preferences. Far fewer studies have investigated the effects of cues to the direction of others' social interest (i.e. gaze direction) on face preferences. Here we found that unpartnered women demonstrated stronger preferences for direct gaze (indicating social interest) from feminine male faces than from masculine male faces when judging men's attractiveness for long-term relationships, but not when judging men's attractiveness for short-term relationships. Moreover, unpartnered women's preferences for direct gaze from feminine men were stronger for long-term than short-term relationships, but there was no comparable effect for judgements of masculine men. No such effects were evident among women with romantic partners, potentially reflecting different motivations underlying partnered and unpartnered women's judgements of men's attractiveness. Collectively these findings (1) complement previous findings whereby women demonstrated stronger preferences for feminine men as long-term than short-term partners, (2) demonstrate context-sensitivity in the integration of physical and social cues in face preferences, and (3) suggest that gaze preferences may function, at least in part, to facilitate efficient allocation of mating effort.

Circum-menopausal effects on women's judgements of facial attractiveness

The marked change in a woman's hormonal profile that happens at menopause affects many aspects of behaviour. We investigated circum-menopausal women's preferences for femininity in the faces of young adult men and women. Post-menopausal women demonstrated stronger preferences for femininity in same-sex faces than pre-menopausal women did. This effect was independent of possible effects of participant's age and suggests that dislike of feminine (i.e. attractive) same-sex competitors decreases as fertility decreases. No significant difference between pre- and post-menopausal women was observed for men's faces, potentially because circum-menopausal women do not necessarily view young adult men as potential mates. To our knowledge, this is the first study to demonstrate circum-menopausal changes in women's face preferences.

Voice pitch alters mate-choice-relevant perception in hunter-gatherers

In humans, voice pitch is thought to be a cue of underlying quality and an important criterion for mate choice, but data from non-Western cultures have not been provided. Here we test attributions to and preferences for voices with raised and lowered pitch in hunter-gatherers. Using a forced-choice playback experiment, we found that both men and women viewed lower pitched voices in the opposite sex as being better at acquiring resources (e.g. hunting and gathering). While men preferred higher pitched women's voices as marriage partners, women showed no overall preference for voice pitch in men. However, women who were currently breastfeeding had stronger preferences for higher pitched male voices whereas women not currently breastfeeding preferred lower pitched voices. As testosterone is considered a costly signal associated with dominance, heritable immunity to infection and low paternal investment, women's preferences potentially reflect a trade-off between securing good genes and paternal investment. Men's preferences for higher pitched female voices are probably due to an evolved preference for markers of fecundity, reflected in voice pitch.

Individual differences in the propensity for partner sexual coercion

Lalumière, Harris, Quinsey, and Rice (2005) proposed a three-path model (psychopathy, young male syndrome, and competitive disadvantage) of the development of sexually coercive behavior, but none of these individual difference characteristics have been tested among partner rapists. Using a community sample in Study 1, the authors find that psychopathy is the only significant predictor of self-reported propensity for partner sexual coercion. This model is tested in Study 2 by comparing convicted partner rapists, nonsexual partner assaulters, and heterosexual child molesters. One third of partner rapists are psychopaths, and their psychopathy scores are no different from those found in correctional samples. Partner rapists have an average IQ, providing further evidence that competitive disadvantage is less characteristic of partner rapists. There is some indication that partner rapists desist with age. The authors discuss these findings in light of recent findings that implicate cuckoldry risk in partner sexual assault.

Testosterone responses to competition in men are related to facial masculinity

Relationships between androgens and the size of sexually dimorphic male traits have been demonstrated in several non-human species. It is often assumed that a similar relationship exists for human male faces, but clear evidence of an association between circulating testosterone levels and the size of masculine facial traits in adulthood is absent. Here we demonstrate that, after experimentally determined success in a competitive task, men with more a masculine facial structure show higher levels of circulating testosterone than men with less masculine faces. In participants randomly allocated to a 'winning' condition, testosterone was elevated relative to pre-task levels at 5 and 20 min post-task. In a control group of participants allocated to a 'losing' condition there were no significant differences between pre- and post-task testosterone. An index of facial masculinity based on the measurement of sexually dimorphic facial traits was not associated with pre-task (baseline) testosterone levels, but was associated with testosterone levels 5 and 20 min after success in the competitive task. These findings indicate that a man's facial structure may afford important information about the functioning of his endocrine system.

Attachment and sexual strategies

Sexual behaviour and mate choice are key intervening variables between attachment and life histories. We propose a set of predictions relating attachment, reproductive strategies, and mate choice criteria.

Preferences across the menstrual cycle for masculinity and symmetry in photographs of male faces and bodies

Background

Previous studies have shown that women increase their preference for masculinity during the fertile phase of the menstrual cycle. Evidence for a similar preference shift for symmetry is equivocal. These studies have required participants to choose between subtle variations in computer-generated stimuli, and preferences for more natural stimuli have not been investigated.

Methodology/Principal Findings

Our study employed photographs of individual males to investigate women's preferences for face and body masculinity and symmetry across the menstrual cycle. We collected attractiveness ratings from 25 normally cycling women at high- and low-fertility days of the menstrual cycle. Attractiveness ratings made by these women were correlated with independent ratings of masculinity and symmetry provided by different sets of raters. We found no evidence for any cyclic shift in female preferences. Correlations between attractiveness and masculinity, and attractiveness and symmetry did not differ significantly between high- and low-fertility test sessions. Furthermore, there was no significant difference between high- and low-fertility ratings of attractiveness.

Conclusions

These results suggest that a menstrual cycle shift in visual preferences for masculinity and symmetry may be too subtle to influence responses to real faces and bodies, and subsequent mate-choice decisions.

Neural Activation in Women in Response to Masculinized Male Faces: Mediation by Hormones and Psychosexual Factors

Women's preference for masculine faces varies with hormonal state, sociosexuality, and relationship status, but the underlying mechanisms are poorly understood. We hypothesized that hormones and psychosexual factors (sociosexuality, sexual inhibition/excitation) mediate the perception and evaluation of male faces thereby influencing women's preferences. We used fMRI to measure brain activity in twelve women as they evaluated pictures of male faces (half 30% masculinized, half 30% feminized). Participants were heterosexual women, age 23-28, who were not in a committed relationship and not using hormonal contraception. Women were tested during both the follicular and luteal phase of their menstrual cycle. We found five brain regions related to face and risk processing that responded more to the masculinized than to the feminized faces, including the superior temporal gyrus, precentral gyrus, posterior cingulate cortex, inferior parietal lobule, and anterior cingulate cortex. Increased activation in the anterior cingulate cortex, specifically, may indicate that women perceive masculinized faces to be both more risky and more attractive. We did not see any areas that were more strongly activated by feminized faces. Levels of activation were influenced by hormonal and psychosexual factors. The patterns of hormonally and psychosexually mediated neural activation observed may offer insight into the cognitive processes underlying women's partner preferences.

Human oestrus

For several decades, scholars of human sexuality have almost uniformly assumed that women evolutionarily lost oestrus--a phase of female sexuality occurring near ovulation and distinct from other phases of the ovarian cycle in terms of female sexual motivations and attractivity. In fact, we argue, this long-standing assumption is wrong. We review evidence that women's fertile-phase sexuality differs in a variety of ways from their sexuality during infertile phases of their cycles. In particular, when fertile in their cycles, women are particularly sexually attracted to a variety of features that likely are (or, ancestrally, were) indicators of genetic quality. As women's fertile-phase sexuality shares with other vertebrate females' fertile-phase sexuality a variety of functional and physiological features, we propose that the term oestrus appropriately applies to this phase in women. We discuss the function of women's non-fertile or extended sexuality and, based on empirical findings, suggest ways that fertile-phase sexuality in women has been shaped to partly function in the context of extra-pair mating. Men are particularly attracted to some features of fertile-phase women, but probably based on by-products of physiological changes males have been selected to detect, not because women signal their cycle-based fertility status.

Changes in Women's Choice of Dress Across the Ovulatory Cycle: Naturalistic and Laboratory Task-Based Evidence

The authors tested the prediction that women prefer clothing that is more revealing and sexy when fertility is highest within the ovulatory cycle. Eighty-eight women reported to the lab twice: once on a low-fertility day of the cycle and once on a high-fertility day (confirmed using hormone tests). In each session, participants posed for full-body photographs in the clothing they wore to the lab, and they drew illustrations to indicate an outfit they would wear to a social event that evening. Although each data source supported the prediction, the authors found the most dramatic changes in clothing choice in the illustrations. Ovulatory shifts in clothing choice were moderated by sociosexuality, attractiveness, relationship status, and relationship satisfaction. Sexually unrestricted women, for example, showed greater shifts in preference for revealing clothing worn to the laboratory near ovulation. The authors suggest that clothing preference shifts could reflect an increase in female—female competition near ovulation.

Men's Faces Convey Information about their Bodies and their Behavior: What you see is what you get

We investigated whether men's faces contain embedded cues that signal differences in individual fitness. Data on shoulder-to-hip ratios (SHR), grip strength, sexual history, and facial photographs were collected from male college students. Female college students rated the photographs for attractiveness We found a striking relationship between ratings of facial attractiveness and body morphology. Males with attractive faces had significantly more masculine, wedge-shaped SHRs. Ratings of facial attractiveness accounted for over 25% of the variance in this sexually dimorphic dimension of male body configuration. Male students with attractive faces also had higher grip strength scores, and more sexual partners. These findings are consistent with a growing body of evidence showing that facial features contain important cues to fitness and hormonal status.

The resting frontal alpha asymmetry across the menstrual cycle: a magnetoencephalographic study

Gonadotropic hormones play an important role in the regulation of emotion. Previous studies have demonstrated that estrogen can modulate appetitive (approach/positive) and aversive (avoidance/negative) affective behaviors during the menstrual cycle. Frontal alpha asymmetry (a measure of relative difference of the alpha power between the two anterior hemispheres) has been associated with the trait and state reactivity of different affective styles. We studied the pattern change of frontal alpha asymmetry across the menstrual cycle. 16 healthy women participated in this resting magneto-encephalographic (MEG) study during the peri-ovulatory (OV) and menstrual (MC) phases. Our results showed significant interaction of resting MEG alpha activity between hemispheric side and menstrual phases. Difference in spontaneous frontal alpha asymmetry pattern across the menstrual cycle was also noted. Relatively higher right frontal activity was found during the OV phase; relatively higher left frontal activity was noted during the MC phase. The alteration of frontal alpha asymmetry might serve a sub-clinical correlate for hormonal modulation effect on dynamic brain organization for the predisposition and conceptualization of different affective styles across the menstrual cycle.

Are attractive people rewarding? Sex differences in the neural substrates of facial attractiveness

The current study examined the neural substrates of facial attractiveness judgments. Based on the extant behavioral literature, it was hypothesized that brain regions involved in identifying the potential reward value of a stimulus would be more active when men viewed attractive women than when women viewed attractive men. To test this hypothesis, we conducted an event-related functional magnetic resonance imaging experiment during which participants provided explicit attractiveness judgments for faces of the opposite sex. These individual ratings were subsequently used to perform analyses aimed at identifying the brain regions preferentially responsive to attractive faces for both sex groups. The results revealed that brain regions comprising the putative reward circuitry (e.g., nucleus accumbens [NAcc], orbito-frontal cortex [OFC]) showed a linear increase in activation with increased judgments of attractiveness. However, further analysis also revealed sex differences in the recruitment of OFC, which distinguished attractive and unattractive faces only for male participants.

Symmetry is related to sexual dimorphism in faces: data across culture and species

Background

Many animals both display and assess multiple signals. Two prominently studied traits are symmetry and sexual dimorphism, which, for many animals, are proposed cues to heritable fitness benefits. These traits are associated with other potential benefits, such as fertility. In humans, the face has been extensively studied in terms of attractiveness. Faces have the potential to be advertisements of mate quality and both symmetry and sexual dimorphism have been linked to the attractiveness of human face shape.

Methodology/Principal Findings

Here we show that measurements of symmetry and sexual dimorphism from faces are related in humans, both in Europeans and African hunter-gatherers, and in a non-human primate. Using human judges, symmetry measurements were also related to perceived sexual dimorphism. In all samples, symmetric males had more masculine facial proportions and symmetric females had more feminine facial proportions.

Conclusions/Significance

Our findings support the claim that sexual dimorphism and symmetry in faces are signals advertising quality by providing evidence that there must be a biological mechanism linking the two traits during development. Such data also suggests that the signalling properties of faces are universal across human populations and are potentially phylogenetically old in primates.

The social brain in adolescence

The term 'social brain' refers to the network of brain regions that are involved in understanding others. Behaviour that is related to social cognition changes dramatically during human adolescence. This is paralleled by functional changes that occur in the social brain during this time, in particular in the medial prefrontal cortex and the superior temporal sulcus, which show altered activity during the performance of social cognitive tasks, such as face recognition and mental-state attribution. Research also indicates that, in humans, these parts of the social brain undergo structural development, including synaptic reorganization, during adolescence. Bringing together two relatively new and rapidly expanding areas of neuroscience--social neuroscience and the study of brain development during adolescence--will increase our understanding of how the social brain develops during adolescence.

Beauty is in the 'we' of the beholder: greater agreement on facial attractiveness among close relations

Scientific research on facial attractiveness has focused primarily on elucidating universal factors to which all raters respond consistently. However, recent work has shown that there is also substantial disagreement between raters, highlighting the importance of determining how attractiveness preferences vary among different individuals. We conducted a typical attractiveness ratings study, but took the unusual step of recruiting pairs of subjects who were spouses, siblings, or close friends. The agreement between pairs of affiliated friends, siblings, and spouses was significantly greater than between pairs of strangers drawn from the same race and culture, providing evidence that facial-attractiveness preferences are socially organized.

Good genes, complementary genes and human mate preferences

The past decade has witnessed a rapidly growing interest in the biological basis of human mate choice. Here we review recent studies that demonstrate preferences for traits which might reveal genetic quality to prospective mates, with potential but still largely unknown influence on offspring fitness. These include studies assessing visual, olfactory and auditory preferences for potential good-gene indicator traits, such as dominance or bilateral symmetry. Individual differences in these robust preferences mainly arise through within and between individual variation in condition and reproductive status. Another set of studies have revealed preferences for traits indicating complementary genes, focussing on discrimination of dissimilarity at genes in the major histocompatibility complex (MHC). As in animal studies, we are only just beginning to understand how preferences for specific traits vary and inter-relate, how consideration of good and compatible genes can lead to substantial variability in individual mate choice decisions and how preferences expressed in one sensory modality may reflect those in another. Humans may be an ideal model species in which to explore these interesting complexities.

Progesterone selectively increases amygdala reactivity in women

The acute neural effects of progesterone are mediated by its neuroactive metabolites allopregnanolone and pregnanolone. These neurosteroids potentiate the inhibitory actions of gamma-aminobutyric acid (GABA). Progesterone is known to produce anxiolytic effects in animals, but recent animal studies suggest that pregnanolone increases anxiety after a period of low allopregnanolone concentration. This effect is potentially mediated by the amygdala and related to the negative mood symptoms in humans that are observed during increased allopregnanolone levels. Therefore, we investigated with functional magnetic resonance imaging (MRI) whether a single progesterone administration to healthy young women in their follicular phase modulates the amygdala response to salient, biologically relevant stimuli. The progesterone administration increased the plasma concentrations of progesterone and allopregnanolone to levels that are reached during the luteal phase and early pregnancy. The imaging results show that progesterone selectively increased amygdala reactivity. Furthermore, functional connectivity analyses indicate that progesterone modulated functional coupling of the amygdala with distant brain regions. These results reveal a neural mechanism by which progesterone may mediate adverse effects on anxiety and mood.

Parent–Offspring Conflict in Mate Preferences

Prevailing evolutionary approaches to human mating have largely ignored the fact that mating decisions are heavily influenced by parents and other kin. This is significant because parents and children often have conflicting mate preferences. We provide a brief review of how parents have influenced their children's mating behavior across cultures and throughout history. Then, by drawing on evolutionary reasoning, we offer a hypothesis for why parents and offspring may have conflicting interests with respect to mate preferences. Specifically, parents may have a relatively stronger preference for children's mates with characteristics suggesting high parental investment and cooperation with the ingroup, whereas children may have a relatively stronger preference for mates with characteristics signaling heritable fitness. We review past research consistent with this hypothesis, and we report new results from an empirical study consisting of 768 participants from a variety of cultures that provided clear support for the hypothesis.

The Best Men Are (Not Always) Already Taken

Because men of higher genetic quality tend to be poorer partners and parents than men of lower genetic quality, women may profit from securing a stable investment from the latter, while obtaining good genes via extrapair mating with the former. Only if conception occurs, however, do the evolutionary benefits of such a strategy overcome its costs. Accordingly, we predicted that (a) partnered women should prefer attached men, because such men are more likely than single men to have pair-bonding qualities, and hence to be good replacement partners, and (b) this inclination should reverse when fertility rises, because attached men are less available for impromptu sex than single men. In this study, 208 women rated the attractiveness of men described as single or attached. As predicted, partnered women favored attached men at the low-fertility phases of the menstrual cycle, but preferred single men (if masculine, i.e., advertising good genetic quality) when conception risk was high.