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.

Facial masculinity is only weakly correlated with handgrip strength in young adult women.

OBJECTIVES: Ancestrally, strength is likely to have played a critical role in determining the ability to obtain and retain resources and the allocation of social status among humans. Responses to facial cues of strength are therefore thought to play an important role in human social interaction. Although many researchers have proposed that sexually dimorphic facial morphology is reliably correlated with physical strength, evidence for this hypothesis is somewhat mixed. Moreover, to date, only one study has investigated the putative relationship between facial masculinity and physical strength in women. Consequently, we tested for correlations between handgrip strength and objective measures of face-shape masculinity. METHODS: 531 women took part in the study. We measured each participant's handgrip strength (dominant hand). Sexual dimorphism of face shape was objectively measured from each face photograph using two methods: discriminant analysis and vector analysis. These methods use shape components derived from principal component analyses of facial landmarks to measure the probability of the face being classified as male (discriminant analysis method) or to locate the face on a female-male continuum (vector analysis method). RESULTS: Our analyses revealed that handgrip strength is, at best, only weakly correlated with facial masculinity in women. There was a weak significant association between handgrip strength and one measure of women's facial masculinity. The relationship between handgrip strength and our other measure of women's facial masculinity was not significant. DISCUSSION: Together, these results do not support the hypothesis that face-shape masculinity is an important cue of physical strength, at least in women.

No Compelling Evidence that Preferences for Facial Masculinity Track Changes in Women's Hormonal Status.

Although widely cited as strong evidence that sexual selection has shaped human facial-attractiveness judgments, findings suggesting that women's preferences for masculine characteristics in men's faces are related to women's hormonal status are equivocal and controversial. Consequently, we conducted the largest-ever longitudinal study of the hormonal correlates of women's preferences for facial masculinity ( N = 584). Analyses showed no compelling evidence that preferences for facial masculinity were related to changes in women's salivary steroid hormone levels. Furthermore, both within-subjects and between-subjects comparisons showed no evidence that oral contraceptive use decreased masculinity preferences. However, women generally preferred masculinized over feminized versions of men's faces, particularly when assessing men's attractiveness for short-term, rather than long-term, relationships. Our results do not support the hypothesized link between women's preferences for facial masculinity and their hormonal status.

No clear evidence for correlations between handgrip strength and sexually dimorphic acoustic properties of voices.

OBJECTIVES: Recent research on the signal value of masculine physical characteristics in men has focused on the possibility that such characteristics are valid cues of physical strength. However, evidence that sexually dimorphic vocal characteristics are correlated with physical strength is equivocal. Consequently, we undertook a further test for possible relationships between physical strength and masculine vocal characteristics. METHODS: We tested the putative relationships between White UK (N = 115) and Chinese (N = 106) participants' handgrip strength (a widely used proxy for general upper-body strength) and five sexually dimorphic acoustic properties of voices: fundamental frequency (F0), fundamental frequency's SD (F0-SD), formant dispersion (Df), formant position (Pf), and estimated vocal-tract length (VTL). RESULTS: Analyses revealed no clear evidence that stronger individuals had more masculine voices. CONCLUSIONS: Our results do not support the hypothesis that masculine vocal characteristics are a valid cue of physical strength.

Are physiological and behavioral immune responses negatively correlated? Evidence from hormone-linked differences in men's face preferences.

Behaviors that minimize exposure to sources of pathogens can carry opportunity costs. Consequently, how individuals resolve the tradeoff between the benefits and costs of behavioral immune responses should be sensitive to the extent to which they are vulnerable to infectious diseases. However, although it is a strong prediction of this functional flexibility principle, there is little compelling evidence that individuals with stronger physiological immune responses show weaker behavioral immune responses. Here we show that men with the combination of high testosterone and low cortisol levels, a hormonal profile recently found to be associated with particularly strong physiological immune responses, show weaker preferences for color cues associated with carotenoid pigmentation. Since carotenoid cues are thought to index vulnerability to infectious illnesses, our results are consistent with the functional flexibility principle's prediction that individuals with stronger physiological immune responses show weaker behavioral immune responses.

Sex-Specificity in the Reward Value of Facial Attractiveness.

Studies of the sex-specificity of sexual arousal in adults (i.e., the tendency to respond more strongly to preferred-sex individuals than non-preferred sex individuals) have suggested that heterosexual men, homosexual men, and homosexual women show stronger sex-specific responses than do heterosexual women. Evidence for a similar pattern of results in studies investigating the reward value of faces is equivocal. Consequently, we investigated the effects of (1) sexual orientation (homosexual vs. heterosexual), (2) sex (male vs. female), (3) image sex (preferred-sex vs. non-preferred-sex), and (4) the physical attractiveness of the individual shown in the image on the reward value of faces. Participants were 130 heterosexual men, 130 homosexual men, 130 heterosexual women, and 130 homosexual women. The reward value of faces was assessed using a standard key-press task. Multilevel modeling of responses indicated that images of preferred-sex individuals were more rewarding than images of non-preferred-sex individuals and that this preferred-sex bias was particularly pronounced when more physically attractive faces were presented. These effects were not qualified by interactions involving either the sexual orientation or the sex of our participants, however, suggesting that the preferred-sex bias in the reward value of faces is similar in heterosexual men, homosexual men, heterosexual women, and homosexual women.

Women's facial attractiveness is related to their body mass index but not their salivary cortisol.

OBJECTIVES: Although many theories of human facial attractiveness propose positive correlations between facial attractiveness and measures of actual health, evidence for such correlations is somewhat mixed. Here we sought to replicate a recent study reporting that women's facial attractiveness is independently related to both their adiposity and cortisol. METHODS: Ninety-six women provided saliva samples, which were analyzed for cortisol level, and their height and weight, which were used to calculate their body mass index (BMI). A digital face image of each woman was also taken under standardized photographic conditions and rated for attractiveness. RESULTS: There was a significant negative correlation between women's facial attractiveness and BMI. By contrast, salivary cortisol and facial attractiveness were not significantly correlated. CONCLUSIONS: Our results suggest that the types of health information reflected in women's faces include qualities that are indexed by BMI but do not necessarily include qualities that are indexed by cortisol. Am. J. Hum. Biol. 28:352-355, 2016. © 2015 Wiley Periodicals, Inc.

Women's Preference for Attractive Makeup Tracks Changes in Their Salivary Testosterone.

Previous research suggests that women's motivation to appear attractive is increased around the time of ovulation. However, the specific hormonal correlates of within-woman changes in motivation to appear attractive have not been investigated. To address this issue, we used a longitudinal design and a data-driven visual preference task. We found that women's preference for attractive makeup increases when their salivary testosterone levels are high. The relationship between testosterone level and preference for attractive makeup was independent of estradiol level, progesterone level, and estradiol-to-progesterone ratio. These results suggest that testosterone may contribute to changes in women's motivation to wear attractive makeup and, potentially, their motivation to appear attractive in general. Our results are also consistent with recent models of the role of testosterone in social behavior, according to which testosterone increases the probability of behaviors that could function to support the acquisition of mates and competition for resources.

The reward value of infant facial cuteness tracks within-subject changes in women's salivary testosterone.

"Baby schema" refers to infant characteristics, such as facial cues, that positively influence cuteness perceptions and trigger caregiving and protective behaviors in adults. Current models of hormonal regulation of parenting behaviors address how hormones may modulate protective behaviors and nurturance, but not how hormones may modulate responses to infant cuteness. To explore this issue, we investigated possible relationships between the reward value of infant facial cuteness and within-woman changes in testosterone, estradiol, and progesterone levels. Multilevel modeling of these data showed that infant cuteness was more rewarding when women's salivary testosterone levels were high. Moreover, this within-woman effect of testosterone was independent of the possible effects of estradiol and progesterone and was not simply a consequence of changes in women's cuteness perceptions. These results suggest that testosterone may modulate differential responses to infant facial cuteness, potentially revealing a new route through which testosterone shapes selective allocation of parental resources.

Reported maternal tendencies predict the reward value of infant facial cuteness, but not cuteness detection.

The factors that contribute to individual differences in the reward value of cute infant facial characteristics are poorly understood. Here we show that the effect of cuteness on a behavioural measure of the reward value of infant faces is greater among women reporting strong maternal tendencies. By contrast, maternal tendencies did not predict women's subjective ratings of the cuteness of these infant faces. These results show, for the first time, that the reward value of infant facial cuteness is greater among women who report being more interested in interacting with infants, implicating maternal tendencies in individual differences in the reward value of infant cuteness. Moreover, our results indicate that the relationship between maternal tendencies and the reward value of infant facial cuteness is not due to individual differences in women's ability to detect infant cuteness. This latter result suggests that individual differences in the reward value of infant cuteness are not simply a by-product of low-cost, functionless biases in the visual system.

Changes in salivary estradiol predict changes in women's preferences for vocal masculinity.

Although many studies have reported that women's preferences for masculine physical characteristics in men change systematically during the menstrual cycle, the hormonal mechanisms underpinning these changes are currently poorly understood. Previous studies investigating the relationships between measured hormone levels and women's masculinity preferences tested only judgments of men's facial attractiveness. Results of these studies suggested that preferences for masculine characteristics in men's faces were related to either women's estradiol or testosterone levels. To investigate the hormonal correlates of within-woman variation in masculinity preferences further, here we measured 62 women's salivary estradiol, progesterone, and testosterone levels and their preferences for masculine characteristics in men's voices in five weekly test sessions. Multilevel modeling of these data showed that changes in salivary estradiol were the best predictor of changes in women's preferences for vocal masculinity. These results complement other recent research implicating estradiol in women's mate preferences, attention to courtship signals, sexual motivation, and sexual strategies, and are the first to link women's voice preferences directly to measured hormone levels.

Sex ratio influences the motivational salience of facial attractiveness.

The sex ratio of the local population influences mating-related behaviours in many species. Recent experiments show that male-biased sex ratios increase the amount of financial resources men will invest in potential mates, suggesting that sex ratios influence allocation of mating effort in humans. To investigate this issue further, we tested for effects of cues to the sex ratio of the local population on the motivational salience of attractiveness in own-sex and opposite-sex faces. We did this using an effort-based key-press task, in which the motivational salience of facial attractiveness was assessed in samples of faces in which the ratio of male to female images was manipulated. The motivational salience of attractive opposite-sex, but not own-sex, faces was greater in the own-sex-biased (high competition for mates) than in the opposite-sex-biased (low competition for mates) condition. Moreover, this effect was not modulated by participant sex. These results present new evidence that sex ratio influences human mating-related behaviours. They also present the first evidence that the perceived sex ratio of the local population may modulate allocation of mating effort in women, as well as men.

Effects of cleft lip on visual scanning and neural processing of infant faces.

Infant faces readily capture adult attention and elicit enhanced neural processing, likely due to their importance evolutionarily in facilitating bonds with caregivers. Facial malformations have been shown to impact early infant-caregiver interactions negatively. However, it remains unclear how such facial malformations may impact early visual processing. The current study used a combination of eye tracking and electroencephalography (EEG) to investigate adults' early visual processing of infant faces with cleft lip/palate as compared to normal infant faces, as well as the impact cleft palate has on perceived cuteness. The results demonstrated a significant decrease in early visual attention to the eye region for infants with cleft palate, while increased visual attention is registered on the mouth region. Increased neural processing of the cleft palate was evident at the N170 and LPP, suggesting differences in configural processing and affective responses to the faces. Infants with cleft palate were also rated significantly less cute than their healthy counterparts (mean difference = .73, p < .001). These results suggest that infants' faces with cleft lip/palate are processed differently at early visual perception. These processing differences may contribute to several important aspects of development (e.g., joint attention) and may play a vital role in the previously observed difficulties in mother-infant interactions.

Hot or not? Thermal reactions to social contact.

Previous studies using thermal imaging have suggested that face and body temperature increase during periods of sexual arousal. Additionally, facial skin temperature changes are associated with other forms of emotional arousal, including fear and stress. This study investigated whether interpersonal social contact can elicit facial temperature changes. Study 1: infrared images were taken during a standardized interaction with a same- and opposite-sex experimenter using skin contact in a number of potentially high-intimate (face and chest) and low-intimate (arm and palm) locations. Facial skin temperatures significantly increased from baseline during the face and chest contact, and these temperature shifts were larger when contact was made by an opposite-sex experimenter. Study 2: the topography of facial temperature change was investigated in five regions: forehead, periorbital, nose, mouth and cheeks. Increased temperature in the periorbital, nose and mouth regions predicted overall facial temperature shifts to social contact. Our findings demonstrate skin temperature changes are a sensitive index of arousal during interpersonal interactions.

No increased inbreeding avoidance during the ovulatory phase of the menstrual cycle.

Mate preferences and mating-related behaviours are hypothesised to change over the menstrual cycle to increase reproductive fitness. Recent large-scale studies suggest that previously reported hormone-linked behavioural changes are not robust. The proposal that women's preference for associating with male kin is down-regulated during the ovulatory (high-fertility) phase of the menstrual cycle to reduce inbreeding has not been tested in large samples. Consequently, we investigated the relationship between longitudinal changes in women's steroid hormone levels and their perceptions of faces experimentally manipulated to possess kinship cues (Study 1). Women viewed faces displaying kinship cues as more attractive and trustworthy, but this effect was not related to hormonal proxies of conception risk. Study 2 employed a daily diary approach and found no evidence that women spent less time with kin generally or with male kin specifically during the fertile phase of the menstrual cycle. Thus, neither study found evidence that inbreeding avoidance is up-regulated during the ovulatory phase of the menstrual cycle.

To which world regions does the valence-dominance model of social perception apply?

Over the past 10 years, Oosterhof and Todorov's valence-dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgements of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov's methodology across 11 world regions, 41 countries and 11,570 participants. When we used Oosterhof and Todorov's original analysis strategy, the valence-dominance model generalized across regions. When we used an alternative methodology to allow for correlated dimensions, we observed much less generalization. Collectively, these results suggest that, while the valence-dominance model generalizes very well across regions when dimensions are forced to be orthogonal, regional differences are revealed when we use different extraction methods and correlate and rotate the dimension reduction solution. PROTOCOL REGISTRATION: The stage 1 protocol for this Registered Report was accepted in principle on 5 November 2018. The protocol, as accepted by the journal, can be found at https://doi.org/10.6084/m9.figshare.7611443.v1 .

Does women's anxious jealousy track changes in steroid hormone levels?

Findings for progesterone and anxiety in non-human animals led to the hypothesis that women's interpersonal anxiety will track changes in progesterone during the menstrual cycle. There have been few direct tests of this hypothesis, however. Consequently, we used a longitudinal design to investigate whether interpersonal anxiety (assessed using the anxious jealousy subscale of the relationship jealousy questionnaire) tracked changes in salivary steroid hormones during the menstrual cycle in a large sample of young adult women. We found no evidence for within-subject effects of progesterone, estradiol, their interaction or ratio, testosterone, or cortisol on anxious jealousy. There was some evidence that other components of jealousy (e.g., reactive jealousy) tracked changes in women's cortisol, however. Collectively, these results provide no evidence for the hypothesis that interpersonal anxiety tracks changes in progesterone during the menstrual cycle.

Are Sexual Desire and Sociosexual Orientation Related to Men's Salivary Steroid Hormones?

OBJECTIVE: Although it is widely assumed that men's sexual desire and interest in casual sex (i.e., sociosexual orientation) are linked to steroid hormone levels, evidence for such associations is mixed. METHODS: We tested for both longitudinal and cross-sectional relationships between salivary testosterone, cortisol, reported sexual desire and sociosexuality in a sample of 61 young adult men, each of whom was tested weekly on up to five occasions. RESULTS: Longitudinal analyses showed no clear relationships between steroid hormones and self-reported sexual desire or sociosexual orientation. Cross-sectional analyses showed no significant associations between average hormone levels and self-reported sexual desire. However, some aspects of sociosexuality, most notably desire for casual sex, were related to men's average hormone levels. Men with higher average testosterone reported greater desire for casual sex, but only if they also had relatively low average cortisol levels. CONCLUSIONS: Our results support a Dual Hormone account of men's sociosexuality, in which the combined effects of testosterone and cortisol predict the extent of men's interest in casual sex. However, we did not detect compelling evidence for an association of within-subject hormone shifts and sexual desire or sociosexual orientation.

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.

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.