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.

Preference for Facial Symmetry Depends on Study Design

Facial symmetry is purportedly attractive, though methods for measuring preference for facial symmetry vary between studies. Some studies have used a two-alternative forced choice (2AFC) task, while others have used a ratings task. How researchers manipulate facial symmetry also varies; some studies have used faces manipulated to be more (or perfectly) symmetrical, while others have used faces manipulated to be more asymmetrical. Here, across three studies, we evaluate and compare these different methods. In Studies 1 and 2 (N = 340 and 256, respectively), we compare facial symmetry preferences as measured by the 2AFC and ratings tasks. Across both studies, we consistently found a significant preference for facial symmetry when using the 2AFC task, but not with the ratings task. Additionally, correlations between facial symmetry preferences as measured by the two tasks were weak or showed no association. In Study 3, 159 participants rated the attractiveness of faces manipulated to be either symmetrical or more asymmetrical. The asymmetrical faces were rated as significantly less attractive compared to the original faces, while the difference in attractiveness ratings between the original and symmetrical versions was comparatively much smaller. These studies suggest that preference for facial symmetry depends greatly on the study design.

Mothers are sensitive to men's beards as a potential cue of paternal investment

Mating strategy theories assert that women's preferences for androgen dependent traits in men are stronger when the costs of reduced paternal investment are lowest. Past research has shown that preferences for facial masculinity are stronger among nulliparous and non-pregnant women than pregnant or parous women. In two studies, we examine patterns in women's preferences for men's facial hair - likely the most visually conspicuous and sexually dimorphic of men's secondary sexual traits - when evaluating men's masculinity, dominance, age, fathering, and attractiveness. Two studies were conducted among heterosexual pregnant women, mothers, non-contractive and contraceptive users. Study 1 used a between-subjects sample (N = 2103) and found that mothers had significantly higher preferences for beards when judging fathering than all other women. Pregnant women and mothers also judged beards as more masculine and older, but less attractive, than non-contractive and contraceptive users. Parous women judged beards higher for age, masculinity and fathering, but lower for attractiveness, than nulliparous women. Irrespective of reproductive status, beards were judged as looking more dominant than clean-shaven faces. Study 2 used a within-subjects design (N = 53) among women surveyed during pregnancy and three months post-partum. Judgments of parenting skills were higher for bearded stimuli during pregnancy among women having their first baby, whereas among parous women parenting skills judgments for bearded stimuli were higher post-partum. Our results suggest that mothers are sensitive to beardedness as a masculine secondary sexual characteristic that may denote parental investment, providing evidence that women's mate preferences could reflect sexual selection for direct benefits.

Women's preferences for men's facial masculinity are strongest under favorable ecological conditions

The strength of sexual selection on secondary sexual traits varies depending on prevailing economic and ecological conditions. In humans, cross-cultural evidence suggests women’s preferences for men’s testosterone dependent masculine facial traits are stronger under conditions where health is compromised, male mortality rates are higher and economic development is higher. Here we use a sample of 4483 exclusively heterosexual women from 34 countries and employ mixed effects modelling to test how social, ecological and economic variables predict women’s facial masculinity preferences. We report women’s preferences for more masculine looking men are stronger in countries with higher sociosexuality and where national health indices and human development indices are higher, while no associations were found between preferences and indices of intra-sexual competition. Our results show that women’s preferences for masculine faces are stronger under conditions where offspring survival is higher and economic conditions are more favorable.

La donna è mobile? Lack of cyclical shifts in facial symmetry, and facial and body masculinity preferences-A hormone based study

Although under investigation for more than two decades, a common agreement on the occurrence of cyclical shifts in women's masculinity and symmetry preferences is still missing. Such shifts are considered to be an important feature of sexual selection as they supposedly direct women's attention towards cues for "good genes" (e.g. masculinity and symmetry) during times when probability of conception is the highest. Multiple studies have, however, failed to find these shifts. We attempt to address this lack of agreement analysing a sample of 110 healthy women, using intra-participant design and repeated measurements of oestradiol and LH during the cycle. To ensure the reliable detection of increased conception probability, both LH- based ovulation tests and multiple oestradiol measurements were used. We found no significant differences between women's preferences during different cycle phases for either body or facial masculinity, or for facial symmetry. Differences remained non-significant after controlling for participants' sexual openness, relationship status, and self-judged attractiveness. We suggest that putative cyclical shifts in preferences for cues for good genes are either very small (impossible to be tracked even with a relatively large sample) or they are far more complex than previously assumed, and further studies accounting for more confounding variables should be undertaken.

Women's preferences for men's beards show no relation to their ovarian cycle phase and sex hormone levels

According to the ovulatory shift hypothesis, women's mate preferences for male morphology indicative of competitive ability, social dominance, and/or underlying health are strongest at the peri-ovulatory phase of the menstrual cycle. However, recent meta-analyses are divided on the robustness of such effects and the validity of the often-used indirect estimates of fertility and ovulation has been called into question in methodological studies. In the current study, we test whether women's preferences for men's beardedness, a cue of male sexual maturity, androgenic development and social dominance, are stronger at the peri-ovulatory phase of the menstrual cycle compared to during the early follicular or the luteal phase. We also tested whether levels of estradiol, progesterone, and the estradiol to progesterone ratio at each phase were associated with facial hair preferences. Fifty-two heterosexual women completed a two-alternative forced choice preference test for clean-shaven and bearded male faces during the follicular, peri-ovulatory (validated by the surge in luteinizing hormone or the drop in estradiol levels) and luteal phases. Participants also provided for one entire menstrual cycle daily saliva samples for subsequent assaying of estradiol and progesterone. Results showed an overall preference for bearded over clean-shaven faces at each phase of the menstrual cycle. However, preferences for facial hair were not significantly different over the phases of menstrual cycle and were not significantly associated with levels of reproductive hormones. We conclude that women's preferences for men's beardedness may not be related to changes in their likelihood of conception.

Men's Sexual Faithfulness Judgments May Contain a Kernel of Truth

Mechanisms enabling men to identify women likely to engage in extra-pair copulations (EPCs) would be advantageous in avoiding cuckoldry. Men's judgments of female sexual faithfulness often show high consensus, but accuracy appears poor. We examined whether accuracy of these judgments made to images of women could be improved through i) employing a forced choice task, in which men were asked to select the more faithful of two women and/or ii) providing men with full person images. In Experiment 1, men rated 34 women, for whom we had self-reported EPC behavior, on faithfulness, trustworthiness or attractiveness from either face or full person photographs. They then completed a forced choice task, selecting the more faithful of two woman from 17 pairs of images, each containing one woman who had reported no EPCs and one who had reported two or more EPCs. Men were unable to rate faithfulness with any accuracy, replicating previous findings. However, when asked to choose the more faithful of two women, they performed significantly above chance, although the ability to judge faithfulness at above-chance levels did not generalize to all pairs of women. Although there was no significant difference in accuracy for face and full person image pairs, only judgments from faces were significantly above chance. In Experiment 2, we showed that this accuracy for faces was repeatable in a new sample of men. We also showed that individual variation in accuracy was unrelated to variation in preferences for faithfulness in a long-term partner. Overall, these results show that men's judgments of faithfulness made from faces of unfamiliar women may contain a kernel of truth.

Testosterone-to-oestradiol ratio is associated with female facial attractiveness

The relationship between facial shape and attractiveness has been extensively studied, yet few studies have investigated the underlying biological factors of an attractive face. Many researchers have proposed a link between female attractiveness and sex hormones, but there is little empirical evidence in support of this assumption. In the present study we investigated the relationship between circulating sex hormones and attractiveness. We created prototypes by separately averaging photographs of 15 women with high and low levels of testosterone, oestradiol, and testosterone-to-oestradiol ratio levels, respectively. An independent set of facial images was then shape transformed toward these prototypes. We paired the resulting images in such a way that one face depicted a female with high hormone level and the other one with a low hormone level. Fifty participants were asked to choose the more attractive face of each pair. We found that low testosterone-to-oestradiol ratio and low testosterone were positively associated with female facial attractiveness. There was no preference for faces with high oestradiol levels. In an additional experiment with 36 participants we confirmed that a low testosterone-to-oestradiol ratio plays a larger role than low testosterone alone. These results provide empirical evidence that an attractive female face is shaped by interacting effects of testosterone and oestradiol.