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 influence of resource-gaining capacity on mate preferences: an eye tracking study

To investigate whether resource-gaining capacity influences mate preferences, explicit (self-report data) and implicit tasks (eye tracking data) were used to explore whether individuals' resource-gaining capacity influences mate preferences and whether there are sex differences in mate preferences under two different conditions (short-term and long-term strategies). A total of 59 college students completed a questionnaire collecting basic demographic information, the Resource-Gaining Capacity Scale and the two above tasks. The results showed that (1) in the short-term mating, individuals with higher resource-gaining capacity paid more attention to "good parent" than those with lower resource-gaining capacity, while individuals with lower resource-gaining capacity preferred "good provider" than those with higher resource-gaining capacity. (2) In the long-term mating, women valued "good provider" traits more than men, and they paid more attention to "good parent" traits than men in the short-term. In addition, no matter in the short-term or the long-term mating, men placed more value on "good genes" traits than women. (3) Compared with long-term mating, individuals of both sexes had preferences based on "good genes" in short-term mating, while they had preferences based on "good parent" and "good provider" in long-term mating compared with short-term mating. (4) Regarding explicit mate selection, "good parent" traits were most preferred by the participants, while the implicit eye tracking data indicated that participants preferred partners who were "good providers" and had "good genes".

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.

The relationship between Chinese college students' mate preferences and their parents' education level

Parents have an influence on the formation of their children's mate preferences. This research conducted two studies to test the relationship between parents' education level and the gender role characteristics (masculinity and femininity) of ideal mate for college students, and the moderating role of urban-rural residence on this relationship. In study 1, 1,033 participants (627 females) reported their explicit attitude toward gender role characteristics for an ideal mate via the Chinese Sex Role Inventory-50. In study 2, we recruited 130 participants (66 females) and used an implicit association test to measure their implicit attitude. Regression-based analyses showed that the higher education level of parents was significantly associated with female students' mate preferences with high-femininity but low-masculinity traits. For male students, the higher education level of parents was associated with their explicit (not implicit) preferences of mates with high-masculinity but low-femininity traits. The significant moderating effect of urban-rural residence was observed in explicit preference, with the different patterns in gender groups. In conclusion, parents with higher educational attainment might bring up children who are more likely to embrace a partner with non-traditional gender roles (e.g., androgynous individuals, feminine men or masculine women).

Dominance or Integration? Influence of Sexual Dimorphism and Clothing Color on Judgments of Male and Female Targets' Attractiveness, Warmth, and Competence

The face is an important source of information in social interactions. Prior studies exploring the mechanism of face perception were consistent with either dominance or integration theory. Studies have shown that both sexually dimorphic features and background cues play essential roles in the formation of impressions and the perception of facial attractiveness. In this study, we conducted two experiments to examine 539 participants' appraisal of attractiveness, warmth, and competence of the target faces of masculine and feminine men and women dressed in red, blue, or white. The results showed that: (1) feminized male/female faces were considered to have a higher degree of attractiveness, warmth, and competence, (2) people rated feminine faces wearing red higher in terms of attractiveness perception, while there was no significant effect of red on attractiveness perception of masculine faces, (3) when evaluating the warmth of targets, the promotion effect of red was found for feminine faces but not for masculine faces. This study, conducted in a pathogen disgust environment, provides direct evidence to support the integration theory over the dominance theory. Feminized red preference found in this study matches Chinese collectivism and the red cultural heritage, which has an important value for people's daily impression management and consumption decisions.

I See Faces! A Review on Face Perception and Attractiveness with a Prosthodontic Peek at Cognitive Psychology

A human face contains a wealth of information about an individual, with which an observer can instinctively make a judgment on the attractiveness of the face. However, despite the profuse literature on facial and smile attractiveness, their origins, determinants, and perceptions remain controversial. The axiom in face processing research is that a face is perceived as an amalgamation of its features, and is referred to as "whole" or "holistic" perception. It is pertinent to the clinician involved in the provision of esthetic restorations to understand this holistic process of face recognition and perception of smile attractiveness. This review paper addresses face recognition and perception of attractiveness by reviewing the holistic perception of faces, including the multidimensional face-space model, and also reviews the smile and facial attractiveness according to the average, multiple motive, and secondary sex characteristics theories.

Emotion regulation by attentional deployment moderates bilinguals' language-dependent emotion differences

Unbalanced bilinguals react differently to emotional stimuli in their first (L1) and second (L2) language. However, the size and direction of the emotion difference varies across emotions and tasks, so that its causes are controversial. Therefore, we investigated if the attentional resources bilinguals allocate to emotion processing moderate their language-dependent emotions. In two experiments, we crossed language and emotion regulation. Study 1 compared effects of distraction and concentration on bilingual emotion-word valence ratings. Study 2 induced positive emotion-focused rumination (or not) prior to a simulated, video-based online-dating activity. It measured emotional attraction to dating candidates speaking the participant's L1 or L2 in pupillary, eye-fixation and self-report responses. The studies found reduced L2 emotions when emotion processing was distracted or when its level was low to start with. Yet, if bilinguals concentrated or had ruminated on their emotions, their self-reported and physiological emotionality was comparable or even stronger in L2, relative to L1. The findings suggest that bilinguals' language-dependent emotions vary with differential language-processing automaticity. We propose that the observed emotion-regulation moderation generates further testable predictions about where and when language choice is relevant for bilinguals' emotions.

Non-Pregnant and Pregnant Women's Femininity Preferences in Male Faces: Tests Based on Within- and Between-Sex Sexual Dimorphism Facial Manipulations

Past research on women's preferences for male facial masculinity in Western cultures has produced inconsistent results. Some inconsistency may be related to the use of different facial stimulus manipulations (e.g., between-sex sexual dimorphic facial manipulation or within-sex sexual dimorphic facial manipulation) that do not perfectly avoid non-facial cues, and pregnancy status may also influence women's face preferences. We therefore recruited pregnant and nonpregnant Chinese women and manipulated the sexual dimorphism of male facial stimuli to explore the influences of manipulation methods, non-facial cues, and pregnancy status on face preferences. Results showed that: (1) in contrast with a general masculinity preference observed in Western cultures, both pregnant and nonpregnant Chinese women preferred feminized and neutral male faces generally; (2) pregnant women's preference for feminized male faces was stable across manipulation methods, while nonpregnant women preferred feminized male faces except under between-sex sexual dimorphism manipulation; and (3) manipulation methods, rather than non-facial cues, influenced participants' face preferences. Specifically, women showed the strongest preferences for femininity when face stimuli were manipulated by within-sex sexual dimorphic facial manipulation, followed by unmanipulated faces and between-sex sexual dimorphic facial manipulation. This effect was stronger for nonpregnant women in the unmanipulated condition and for pregnant women in the between-sex sexual dimorphic facial manipulation. This research provides empirical evidence of women's preferences for sexual dimorphism in male faces in a non-Western culture, as well as the effects of facial manipulation methods, pregnancy status, and the interactions between these factors.

Effects of Women's Short-Term Mating Orientation and Self-Perceived Attractiveness in Rating and Viewing Men's Waist to Chest Ratios

Women's mating strategies are dependent on multiple factors, such as identifying which men advertise physical features indicating high genetic quality, as well as identifying which men are willing to invest in offspring. Research has suggested that women pursuing short-term mating prioritize physical attraction to facilitate the acquisition of good genes. Although it is known that physical characteristics are important in mate choice, research investigating the saliency of physical features in assessing male fitness has not been readily explored. The current study used an eye-tracking paradigm to investigate the role of short-term mating in women and their attraction and visual attention to men's waist to chest ratios (WCRs). Women's short-term mating orientation (N = 130) was associated with attraction to men with low WCRs; however, their visual attention was not influenced by their mating strategy. Interestingly, women who perceived themselves as attractive rated men with low WCRs as more attractive and allocated attentional resources to physical features important in mate choice, such as the head and midriff region. The findings from this study lend some support to sexual strategies theory (Buss & Schmitt, 1993) and strategic pluralism (Gangestad & Simpson, 2000), and they suggest that mate preferences may be calibrated as a function of one's mate value.

Oxidative stress as a hidden cost of attractiveness in postmenopausal women

Perceived facial attractiveness, a putative marker of high biological fitness, is costly to maintain throughout a lifetime and may cause higher oxidative stress (OS). We investigated the association between the facial features of 97 postmenopausal women and their levels of OS biomarkers 8-hydroxy-2′-deoxyguanosine (8-OHdG), superoxide dismutase (Cu-Zn SOD), and thiobarbituric acid reactive substances (TBARS). In study 1, 966 judges rated the composites (facial averages) of women with higher OS as more attractive, healthier, younger, and less symmetric. In study 2, Geometric Morphometric analysis did not reveal significant differences in facial morphology depending on OS levels. In study 3, measured facial averageness and symmetry were weakly negatively related to 8-OHdG levels. Maintaining higher perceived facial attractiveness may be costly due to increased oxidative damage in the postmenopausal period. These costs may remain hidden during the reproductive period of life due to the protective mechanisms of oxidative shielding and revealed only after menopause when shielding has ceased.

The relationship between dispositional attention to feelings and visual attention to emotion

Attention to feelings is a core dimension of individual differences in the perception of one's emotions. It concerns the frequency with which own emotions are attended to. The aim of the present eye-tracking investigation was to examine the relationship of dispositional attention to feelings with early and late attentional processes in the visual perception of emotional information. Attentional orientation was assessed in a sample of healthy women (N = 91) using eye-tracking during a free viewing task in which images with positive, negative and neutral content were shown simultaneously. Pictures were taken from the Besançon Affective Picture Set. State and trait affect, depression, and intelligence of participants were controlled. In our sample, attention to feelings was not related to positive affect, negative affect, depression or intelligence. Attention to feelings was negatively correlated with entry times for all emotional picture types. Moreover, attention to feelings was positively correlated with dwell time on positive images and negatively correlated with dwell time on neutral images. Our data indicate that devoting habitually attention to one's feelings is linked to an enhanced initial orientation of attention towards emotional scenes, irrespective of affective valence. Dispositional attention to feelings might also be associated with an attentional preference for emotional over neutral visual stimuli. The present findings on general individual differences in attention to feelings could have important implications for future clinical research on attentional biases.

Stability of women's facial shape throughout the menstrual cycle

Facial characteristics can serve as a cue for judgements of multiple human traits, from maternal tendencies, overall fertility to sexual openness. In this study, we tested previously found fluctuations in facial shape throughout the menstrual cycle. With methods more robust than those formerly used (larger sample size and detailed hormonal assessments determining the timing of the ovulation), we did not find significant changes in either of the three facial measurements conducted: symmetry, averageness and sexual dimorphism (all F ≤ 0.78, all partial η² ≤ 0.01, all p ≥ 0.542). After narrowing the sample to cycles that had a higher probability of being ovulatory (based on daily measurements of luteinizing hormone and oestradiol), the results remained non-significant (all F ≤ 1.20, all partial η² ≤ 0.03, all p ≥ 0.315). Our results (i) suggest that the previously found increased facial attractiveness of women in the most fertile phase of the menstrual cycle is not driven by changes in facial shape, but might instead stem from other changes in facial appearance, such as a more attractive skin tone; and (ii) underline the importance of replication of studies with new methods.

A Comparison of Masculinity Facial Preference Among Naturally Cycling, Pregnant, Lactating, and Post-Menopausal Women

Women show cyclical shifts in preferences for physical male traits. Here we investigated how fertility status influences women's facial masculinity preference in men by analyzing a large sample of heterosexual women (N = 3720). Women were regularly either cycling (in both low- and high-conception probability groups), lactating or were currently in a non-fertile state (pregnant or post-menopausal). Analyses simultaneously controlled for women's age and sexual openness. Participants via two alternative forced choice questions judged attractiveness of masculinized and feminized men's faces. After controlling for the effect of age and sociosexuality, regularly cycling and pregnant women showed a stronger preference for masculinity than lactating and post-menopausal women. However, there was no significant difference in masculinity preference between women in the low- and high-conception probability groups. Women's sociosexuality showed a positive, but very weak association with men's facial masculinity preference. We suggest that women's overall, long-term hormonal state (cycling, post-menopausal) is a stronger predictor of preference for sexual dimorphism than changes in hormonal levels through the cycle.

Women's self-rated attraction to male faces does not correspond with physiological arousal

There has been little work to determine whether attractiveness ratings of faces correspond to sexual or more general attraction. We tested whether a measure of women’s physiological arousal (pupil diameter change) was correlated with ratings of men’s facial attractiveness. In Study 1, women rated the faces of men for whom we also measured salivary testosterone. They rated each face for attractiveness, and for desirability for friendship and long- and short-term romantic relationships. Pupil diameter change was not related to subjective ratings of attractiveness, but was positively correlated with the men’s testosterone. In Study 2 we compared women’s pupil diameter change in response to the faces of men with high versus low testosterone, as well as in response to non-facial images pre-rated as either sexually arousing or threatening. Pupil dilation was not affected by testosterone, and increased relatively more in response to sexually arousing than threatening images. We conclude that self-rated preferences may not provide a straightforward and direct assessment of sexual attraction. We argue that future work should identify the constructs that are tapped via attractiveness ratings of faces, and support the development of methodology which assesses objective sexual attraction.

Deployment of attention to emotional pictures varies as a function of externally-oriented thinking: An eye tracking investigation

BACKGROUND AND OBJECTIVES

Alexithymia is a multidimensional personality construct including the components difficulties identifying feelings (DIF), difficulties describing feelings (DDF), and externally oriented thinking (EOT). Different features of alexithymia are thought to reflect specific deficits in the cognitive processing and regulation of emotions. The aim of the present study was to examine for the first time patterns of deployment of attention as a function of alexithymia components in healthy persons by using eye-tracking technology. It was assumed that EOT is linked to avoidance of negative images.

METHODS

99 healthy adults viewed freely pictures consisting of anxiety-related, depression-related, positive, and neutral images while gaze behavior was registered. Alexithymia was assessed by the 20-Item Toronto Alexithymia Scale. Measures of anxiety, depression, and (visual-perceptual) intelligence were also administered.

RESULTS

A main effect of emotion condition on dwell times was observed. Viewing time was lowest for neutral images, longer for depression-related and happy images, and longest for anxiety-related images. Gender and EOT had significant effects on dwell times. EOT correlated negatively with dwell time on depression-related (but not anxiety-related) images. There were no correlations of dwell times with depression, trait anxiety, intelligence, DIF, or DDF.

LIMITATIONS

Alexithymia was assessed exclusively by self-report.

CONCLUSIONS

Our results show that EOT but not DIF or DDF influences attention deployment to simultaneously presented emotional pictures. EOT may reduce attention allocation to dysphoric information. This attentional characteristic of EOT individuals might have mood protecting effects but also detrimental impacts on social relationships and coping competencies.

How men and women respond to hypothetical parental discovery: the importance of genetic relatedness

Paternal uncertainty has shaped human behavior both in evolutionary and cultural terms. There has been much research investigating parenting as a function of genetic relatedness to the child, with a focus on male behavior, but the nature of these sex differences is hard to evaluate. We devised a hypothetical scenario that was as similar as possible for men and women to test whether, even in such a scenario, sex differences would remain strong. Participants were presented with the discovery that a child that s/he believed to be theirs was not carrying their own genes. Irrespective of sex, participants (n = 1007) were more upset when the baby was not genetically related to them than when the child was genetically related but the sex gamete was not from a chosen donor. Women were more upset than men in both scenarios, but were more likely to want to keep the baby. The results are discussed with reference to evolved and rational mechanisms affecting parenting.