The Role of Sexual and Romantic Attraction in Human Mate Preferences.

Sex differences in mate preferences are ubiquitous, having been evidenced across generations and cultures. Their prevalence and persistence have compellingly placed them in the evolutionarily adaptive context of sexual selection. However, the psycho-biological mechanisms contributing to their generation and maintenance remain poorly understood. As such a mechanism, sexual attraction is assumed to guide interest, desire, and the affinity toward specific partner features. However, whether sexual attraction can indeed explain sex differences in partner preferences has not been explicitly tested. To better understand how sex and sexual attraction shape mate preferences in humans we assessed how partner preferences differed across the spectrum of sexual attraction in a sample of 479 individuals that identified as asexual, gray-sexual, demisexual or allosexual. We further tested whether romantic attraction predicted preference profiles better than sexual attraction. Our results show that sexual attraction accounts for highly replicable sex differences in mate preferences for high social status and financial prospects, conscientiousness, and intelligence; however, it does not account for the enhanced preference for physical attractiveness expressed by men, which persists even in individuals with low sexual attraction. Instead, sex differences in physical attractiveness preference are better explained by the degree of romantic attraction. Furthermore, effects of sexual attraction on sex differences in partner preferences were grounded in current rather than previous experiences of sexual attraction. Taken together, the results support the idea that contemporary sex differences in partner preferences are maintained by several psycho-biological mechanisms that evolved in conjunction, including not only sexual but also romantic attraction.

Increasing the use of multimodal analgesia during adult surgery in a tertiary academic anaesthesia department.

OBJECTIVE: Multimodal analgesia pathways have been shown to reduce opioid use and side effects in surgical patients. A quality improvement initiative was implemented to increase the use of multimodal analgesia in adult patients presenting for general anaesthesia at an academic tertiary care centre. The aim of this study was to increase adoption of a perioperative multimodal analgesia protocol across a broad population of surgical patients. The use of multimodal analgesia was tracked as a process metric. Our primary outcome was opioid use normalised to oral morphine equivalents (OME) intraoperatively, in the postanaesthesia care unit (PACU), and 48 hours postoperatively. Pain scores and use of antiemetics were measured as balancing metrics. METHODS: We conducted a quality improvement study of a multimodal analgesia protocol implemented for adult (≥18 and≤70) non-transplant patients undergoing general anaesthesia (≥180 min). Components of multimodal analgesia were defined as (1) preoperative analgesic medication (acetaminophen, celecoxib, diclofenac, gabapentin), (2) regional anaesthesia (peripheral nerve block or catheter, epidural catheter or spinal) or (3) intraoperative analgesic medication (ketamine, ketorolac, lidocaine infusion, magnesium, acetaminophen, dexamethasone ≥8 mg, dexmedetomidine). We compared opioid use, pain scores and antiemetic use for patients 1 year before (baseline group-1 July 2018 to 30 June 2019) and 1 year after (implementation group-1 July 2019 to 30 June 2020) project implementation. RESULTS: Use of multimodal analgesia improved from 53.9% in the baseline group to 67.5% in the implementation group (p<0.001). There was no significant difference in intraoperative OME use before and after implementation (ß0=44.0, ß2=0.52, p=0.875). OME decreased after the project implementation in the PACU (ß0=34.4, ß2=-3.88, p<0.001) and 48 hours postoperatively (ß0=184.9, ß2=-22.59, p<0.001), while pain scores during those time points were similar. CONCLUSION: A perioperative pragmatic multimodal analgesic intervention was associated with reduced OME use in the PACU and 48 hours postoperatively.

The Role of Vision in the Emergence of Mate Preferences.

Cross-cultural research has repeatedly demonstrated sex differences in the importance of partner characteristics when choosing a mate. Men typically report higher preferences for younger, more physically attractive women, while women typically place more importance on a partner's status and wealth. As the assessment of such partner characteristics often relies on visual cues, this raises the question whether visual experience is necessary for sex-specific mate preferences to develop. To shed more light onto the emergence of sex differences in mate choice, the current study assessed how preferences for attractiveness, resources, and personality factors differ between sighted and blind individuals using an online questionnaire. We further investigate the role of social factors and sensory cue selection in these sex differences. Our sample consisted of 94 sighted and blind participants with different ages of blindness onset: 19 blind/28 sighted males and 19 blind/28 sighted females. Results replicated well-documented findings in the sighted, with men placing more importance on physical attractiveness and women placing more importance on status and resources. However, while physical attractiveness was less important to blind men, blind women considered physical attractiveness as important as sighted women. The importance of a high status and likeable personality was not influenced by sightedness. Blind individuals considered auditory cues more important than visual cues, while sighted males showed the opposite pattern. Further, relationship status and indirect, social influences were related to preferences. Overall, our findings shed light on the availability of visual information for the emergence of sex differences in mate preference.

Heterogeneity in the Sexual Orientations of Men Who Have Sex with Fa'afafine in Samoa.

In Samoa, feminine natal males who possess male-typical genitalia are known locally as fa'afafine. Some Samoan men express sexual interest in fa'afafine, whereas others do not. To assess the sexual orientation of men who are sexually interested in fa'afafine, we collected sexual attraction ratings and viewing times of Samoan men's and women's faces. Study 1 (N = 130) focused on men who were insertive or versatile during anal sex with fa'afafine partners. These men were compared to each other, as well as to males (i.e., men and fa'afafine) who were exclusively sexually interested in either women or men. Study 2 (N = 180) compared men who had sex with fa'afafine and women; men who had sex with fa'afafine, women, and men; and men who had sex with fa'afafine and men. These men were compared to each other, as well as to males who were exclusively sexually interested in either women or men. These studies suggest that men who have sex with fa'afafine are a heterogeneous group. A small portion of the men who are sexually interested in fa'afafine shows a relatively bisexual pattern of sexual attraction ratings and viewing times, namely men who have sex with fa'afafine, men, and women. In contrast, a larger number of men who were sexually interested in fa'afafine responded in a manner similar to men who were exclusively sexually interested in either women or men. The present research suggests that additional insights into male sexual orientation can be garnered by focusing on how sexuality is expressed in non-Western cultural contexts.

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.

Mate retention Strategies, Self-Esteem, Mate Value and Facial Attractiveness Disparity in Brazil and in the UK.

This study compared mate retention strategies (MRS) in Brazil and in the UK, testing whether culture moderates the association between MRS and self-evaluated variables (e.g. mate value). Our findings demonstrated that women's MRS varied cross-culturally, with Brazilian women reporting to perform MRS more often than British women. Men's MRS did not vary between cultures. Additionally, culture moderated the association between MRS frequency and facial attractiveness disparity (the difference in attractiveness between partners) and mate value. This study presents initial evidence on the influence of culture on the frequency of MRS and its role in the association between self-evaluation and strategies designed to retain a partner.

Comparison of Resource Utilization and Length of Hospitalization Between Overweight and Healthy-Weight Pediatric Trauma Patients Presenting to a Pediatric Emergency Department With Moderate to Severe Injury: A Prospective Study.

OBJECTIVES: Our study aimed to compare overweight and healthy-weight pediatric trauma patient outcomes, specifically with respect to hospital length of stay and resource utilization. We hypothesized that overweight pediatric trauma patients would have increased hospital length of stay and radiographic study use compared with their healthy-weight counterparts. METHODS: This was a prospective, observational, cohort study of pediatric trauma patients aged 2 to 19 years presenting to an urban pediatric emergency department over a period of 1 year. Using measured height and weight values, body mass index (BMI) for age was calculated and plotted on the Centers for Disease Control and Prevention BMI-for-age growth charts. Patients were followed up throughout their hospitalization, and the following items were recorded: trauma alert level, mechanism of injury, age, sex, race, Glasgow Coma Scale score, total number of days in hospital, total number of intensive care unit days, total number of radiographs obtained, total number of computed tomography scans obtained, and mechanism of injury. RESULTS: Our study population included 109 subjects. The mean age of the subjects was 9.7 years. The number of patients meeting the definition of obese (BMI for age ≥95%) was 15, or 14% of the total study population. There was no significant difference between the overweight cohort and the healthy-weight cohort found among any of the variables recorded and analyzed. CONCLUSIONS: Although there are many chronic conditions in children associated with obesity, in the case of trauma, it does not seem to be a strong concern. A continued focus on preventing and reversing childhood obesity for other physical and mental health outcomes may be more important.

Viewing Time and Self-Report Measures of Sexual Attraction in Samoan Cisgender and Transgender Androphilic Males.

Across cultures, androphilic males (natal males who are predominantly sexually attracted to adult men, not women) tend to present in one of two forms: cisgender or transgender. Previous research has shown that, although their gender presentation and identities are distinct, the two forms are similar in many other ways. The present study examined whether cisgender and transgender androphilic males exhibit a similar pattern of self-reported sexual attraction and viewing time response to images of men and women, and one that is directly inverse to that of cisgender gynephilic males (natal males who are predominately sexually attracted to adult women, not men). Using measures of self-reported sexual attraction and viewing time, we compared the response patterns of Samoan cisgender males who self-identified as men, were predominantly attracted to men, and had sex only with men (N = 16) and Samoan transgender males who self-identified as fa'afafine, were predominantly attracted to men, and had sex only with men (N = 30). Samoan cisgender males who self-identified as men, were predominantly attracted to women, and had sex only with women (N = 31) served as a comparison group. Androphilic men and fa'afafine reported greater sexual attraction to men than women and viewed the images of men longer than those of women. Gynephilic men showed the inverse pattern. Viewing time discrepancies between participant's preferred gender and their non-preferred gender were greater for gynephilic men compared to the two androphilic groups. The implications of these preliminary findings for the use of viewing time measures of male sexual orientation across different cultural contexts are discussed.

Average ovarian hormone levels, rather than daily values and their fluctuations, are related to facial preferences among women.

Hormones are of crucial importance for human behavior. Cyclical changes of ovarian hormones throughout women's menstrual cycle are suggested to underlie fluctuation in masculinity preference for both faces and bodies. In this study we tested this hypothesis based on daily measurements of estradiol and progesterone throughout menstrual cycle, and multiple measurements of women's preference towards masculinity of faces and bodies of men. We expected that due to a large variation among daily hormonal levels we would not observe a direct effect of daily hormone levels, but rather that average levels of ovarian hormones throughout the cycle (a reliable marker of a probability of conception) would better predict women's preferences. We found a negative relationship between average progesterone levels and facial masculinity preference, but only among women who were in long-term relationships. There was no relationship between facial masculinity preference and either of the estradiol or progesterone daily levels. Similarly, only average levels of hormones were significantly related to facial symmetry preference. For women who were in relationships estradiol was positively related to symmetry preference, while for single women this relationship was opposite. For body masculinity preference there were no significant relationships with neither averaged nor daily hormonal levels. Taken together, our results further suggest that overall cycle levels of ovarian hormones (averaged for a cycle) are better predictors of facial masculinity and symmetry preference than daily levels assessed during preferences' tests. Importantly, including information about relationship status in the investigations of hormonal bases of preferences is crucial.

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.

Costs of reproduction are reflected in women's faces: Post-menopausal women with fewer children are perceived as more attractive, healthier and younger than women with more children.

OBJECTIVES: The costs associated with reproduction (i.e., gestation, lactation, childcare) have long-term negative consequences by elevating risk of disease and reducing lifespan. We tested the hypotheses that high parity, and thus high reproductive costs bear by women, is perceived by other people when they evaluate facial appearance of health, attractiveness and age of mothers. MATERIALS AND METHODS: Using computer software we created average facial images based on real photographs of post-menopausal women with varying number of children; 3 parity categories were created (1-2, 4-5, and 7-9 children). Study participants (N = 571) were asked to choose the face they perceived as more attractive, younger and healthier via two-alternative forced choice questions asked in three randomized blocks. RESULTS: Women who had given birth to fewer children were judged both by men and women as more attractive, younger and healthier than women with more children. In each category the lowest scores were received by women from highest parity category (7-9 children). DISCUSSION: Mechanisms behind the observed variation in facial appearance are not known but higher levels of oxidative stress among women with high parity may explain their faster aging and lower attractiveness in older age. These results suggest that costs of reproduction might affect women's physical appearance.

Perceived differences in social status between speaker and listener affect the speaker's vocal characteristics.

Non-verbal behaviours, including voice characteristics during speech, are an important way to communicate social status. Research suggests that individuals can obtain high social status through dominance (using force and intimidation) or through prestige (by being knowledgeable and skilful). However, little is known regarding differences in the vocal behaviour of men and women in response to dominant and prestigious individuals. Here, we tested within-subject differences in vocal parameters of interviewees during simulated job interviews with dominant, prestigious, and neutral employers (targets), while responding to questions which were classified as introductory, personal, and interpersonal. We found that vocal modulations were apparent between responses to the neutral and high-status targets, with participants, especially those who perceived themselves as low in dominance, increasing fundamental frequency (F0) in response to the dominant and prestigious targets relative to the neutral target. Self-perceived prestige, however, was less related to contextual vocal modulations than self-perceived dominance. Finally, we found that differences in the context of the interview questions participants were asked to respond to (introductory, personal, interpersonal), also affected their vocal parameters, being more prominent in responses to personal and interpersonal questions. Overall, our results suggest that people adjust their vocal parameters according to the perceived social status of the listener as well as their own self-perceived social status.

An evolutionary approach to accuracy in social perception.

An evolutionary approach highlights that accuracy should be expected over error because selection pressures will have shaped social perception to be functional. Behaviour is extremely complex and so it is unlikely that observers will be perfectly accurate, but an evolutionary view strongly predicts that people will behave as rational observers and in many cases social perception should favour adaptive responses.

Evolutionary explanations for financial and prosocial biases: Beyond mating motivation.

Mating motivation likely plays a role in bias to attractive individuals, but there are other complementary theories drawn from the evolutionary literature related to competition, friendship, and leadership selection that also make relevant predictions concerning biases towards attractive individuals. The relative balance of these factors will be context dependent and so help explain why the pattern of bias is sometimes variable.

Are there vocal cues to human developmental stability? Relationships between facial fluctuating asymmetry and voice attractiveness.

Fluctuating asymmetry (FA), deviation from perfect bilateral symmetry, is thought to reflect an organism's relative inability to maintain stable morphological development in the face of environmental and genetic stressors. Previous research has documented negative relationships between FA and attractiveness judgments in humans, but scant research has explored relationships between the human voice and this putative marker of genetic quality in either sex. Only one study (and in women only) has explored relationships between vocal attractiveness and asymmetry of the face, a feature-rich trait space central in prior work on human genetic quality and mate choice. We therefore examined this relationship in three studies comprising 231 men and 240 women from two Western samples as well as Hadza hunter-gatherers of Tanzania. Voice recordings were collected and rated for attractiveness, and FA was computed from two-dimensional facial images as well as, for a subset of men, three-dimensional facial scans. Through meta-analysis of our results and those of prior studies, we found a negative association between FA and vocal attractiveness that was highly robust and statistically significant whether we included effect sizes from previously published work, or only those from the present research, and regardless of the inclusion of any individual sample or method of assessing FA (e.g., facial or limb FA). Weighted mean correlations between FA and vocal attractiveness across studies were -.23 for men and -.29 for women. This research thus offers strong support for the hypothesis that voices provide cues to genetic quality in humans.

Effect of Partnership Status on Preferences for Facial Self-Resemblance.

Self-resemblance has been found to have a context-dependent effect when expressing preferences for faces. Whereas dissimilarity preference during mate choice in animals is often explained as an evolutionary adaptation to increase heterozygosity of offspring, self-resemblance can be also favored in humans, reflecting, e.g., preference for kinship cues. We performed two studies, using transformations of facial photographs to manipulate levels of resemblance with the rater, to examine the influence of self-resemblance in single vs. coupled individuals. Raters assessed facial attractiveness of other-sex and same-sex photographs according to both short-term and long-term relationship contexts. We found a preference for dissimilarity of other-sex and same-sex faces in single individuals, but no effect of self-resemblance in coupled raters. No effect of sex of participant or short-term vs. long-term attractiveness rating was observed. The results support the evolutionary interpretation that dissimilarity of other-sex faces is preferred by uncoupled individuals as an adaptive mechanism to avoid inbreeding. In contrast, lower dissimilarity preference of other-sex faces in coupled individuals may reflect suppressed attention to attractiveness cues in potential alternative partners as a relationship maintenance mechanism, and its substitution by attention to cues of kinship and psychological similarity connected with greater likelihood of prosocial behavior acquisition from such persons.

Sex Differences in the Perceived Dominance and Prestige of Women With and Without Cosmetics.

Women wearing cosmetics have been associated with a higher earning potential and higher status jobs. However, recent literature suggests that status can be accrued through two distinct routes: dominance and prestige. In two experiments, we applied a standardized amount of cosmetics to female faces using computer software. We then asked participants to rate faces with and without cosmetics for various traits including attractiveness, dominance, and prestige. Men and women both rated the faces with cosmetics added as higher in attractiveness. However, only women rated faces with cosmetics as higher in dominance, while only men rated them as higher in prestige. In a follow-up study, we investigated whether these enhanced perceptions of dominance from women were caused by jealousy. We found that women experience more jealousy toward women with cosmetics, and view these women as more attractive to men and more promiscuous. Our findings suggest that cosmetics may function as an extended phenotype and can alter other's perceptions differently depending on the perceiver's sex.