Effects of Male Facial Masculinity on Perceived Attractiveness

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.

The role of facial cues in signalling cooperativeness is limited and nuanced

Humans display a remarkable tendency to cooperate with strangers; however, identifying prospective cooperation partners accurately before entering any new relationship is essential to mitigate the risk of being exploited. Visual appearance, as inferrable, for example, from facial images on job portals and dating sites, may serve as a potential signal of cooperativeness. This experimental study examines whether static images enable the correct detection of an individual's propensity to cooperate. Participants first played the Prisoner's Dilemma (PD) game, a standard cooperation task. Subsequently, they were asked to predict the cooperativeness of participants from a prior PD study relying solely on their static facial photographs. While our main results indicate only marginal accuracy improvements over random guessing, a more detailed analysis reveals that participants were more successful at identifying cooperative tendencies similar to their own. Despite no detectable main effect in our primary treatment variations (time pressure versus time delay), participants exhibited increased accuracy in identifying male cooperators under time pressure. These findings point towards a limited yet nuanced role of static facial images in predicting cooperativeness, advancing our understanding of non-behavioral cues in cooperative interactions.

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

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

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

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

Socioeconomic position, immune function, and its physiological markers

The development of costly traits such as immune function and secondary sexual traits is constrained by resource availability. The quality of developmental conditions and the availability of resources in ontogeny may therefore influence immune system functions and other biological traits. We analyzed causal pathways between family socioeconomic position, strength of immune response, and five physiological biomarkers in young Latvian men (n = 93) using structural equation modeling. Men from wealthier families had higher testosterone levels (r_s = 0.280), stronger immune response (r_s = 0.551), and higher facial attractiveness (r_s = 0.300). There were weak, non-significant correlations between family income, body fat percentage (r_s = -0.147), and fluctuating asymmetry (r_s = -0.159). Testosterone partially (33.8%) mediated the effect of family income on facial masculinity. Testosterone (positively) and adiposity (negatively) partially (4%) mediated the relationship between family income and immune function. Higher facial masculinity, higher facial symmetry, and lower adiposity were reliable and independent cues of better immune function (R² = 0.238) in a larger sample of young Latvian men (N = 146). Resource availability in ontogeny has an important role for the development of immune function and physical appearance, and it is a key parameter to be included in human eco-immunological research.

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.