Associations between 2D:4D from direct and radiographic measurements with handgrip strength in young adult Tuvans.

BACKGROUND: Digit ratio (2D:4D) - the relative lengths of the index and ring finger - is sexually dimorphic (male < female), possibly because of the sex-differentiated impact of prenatal androgenization on fetal development in the 1st trimester. The sex difference remains stable with age and has been reported in children, adolescents, and adults from industrialized and non-industrialized societies. Handgrip strength (HGS) also is sexually dimorphic (males > females) and correlates negatively with 2D:4D. AIMS: To examine in a sample of young adult Tuvans from Siberia (Russian Federation): i) the association between 2D:4D measured directly from the palms with 2D:4D measured from radiographic images of the same individuals and ii) the associations between 2D:4D and HGS in Tuvan men and women. STUDY DESIGN AND SUBJECTS: The study was cross-sectional. Participants were Tuvans (n = 185; 80 men; mean age = 21.02 years). 2D:4D was measured with a caliper from the ventral surface of the palm (both hands) and from radiographic images (left hand). HGS of both hands was measured with a digital hand dynamometer. Body height and weight were measured with an anthropometer and a body composition scale. RESULTS: 2D:4D ratios and anthropometric measures (including HGS) were sexually dimorphic. Men had lower 2D:4D and higher HGS than women. Direct measures of 2D:4D correlated positively with 2D:4D measured from radiographs. Body mass index (BMI) was a significant predictor of HGS for both sexes. Male right 2D:4D and female right and left 2D:4D correlated negatively with HGS after controlling for the influence of BMI. There were no associations with radiographic measurements of 2D:4D. CONCLUSION: Our findings provide evidence of sexual dimorphism in 2D:4D among young adult Tuvans. Together with previous research on Tuvan children and adolescents, these findings provide clear evidence of 2D:4D sexual dimorphism in pre- and postpubertal Tuvans. The small negative association between 2D:4D and HGS corresponds to similar reports across populations, suggesting that 2D:4D is a weak correlate of muscular fitness.

Male facial cues to physical strength in Europe: Medium-strength preference and higher aggressiveness attribution to the weakest.

OBJECTIVES: The capacity to assess male physical strength from facial cues may be adaptive given health and fitness-related associations with muscular strength. Our study complements recent research on strength-related face perceptions of male Maasai by applying the protocol to male European faces and assessors. METHODS: Five distinct facial morphs calibrated for handgrip strength (HGS) were manufactured with geometric morphometrics performing regressions of the Procrustes shape coordinates on HGS in a sample of 26 European men (18-32 years). Young adult men and women (n = 445) rated these morphs on physical strength, attractiveness, and aggressiveness. RESULTS: Facial morphs calibrated to lower HGS were rated as less strong, less attractive, and more aggressive than those calibrated to higher HGS. Medium levels of HGS were associated with the highest attractiveness ratings. CONCLUSIONS: The rating patterns of physical strength, attractiveness, and aggressiveness for European male facial morphs exhibit similarity to previous ratings of Maasai male faces. Therefore, the current findings corroborate the suggestion of a common mechanism for social attributions based on facial cues to physical strength, modulated by local ecology and societal context.

Digit Ratio (2D:4D; Right-Left 2D:4D) and Multiple Phenotypes for Same-Sex Attraction: The BBC Internet Study Revisited.

Same-sex attraction may be linked to low prenatal androgen (in men) and high prenatal androgen (in women). Digit ratio (2D:4D) is thought to be a negative correlate of prenatal androgen and right-left 2D:4D (Dr-l) to reflect lateralized differences in sensitivity to prenatal androgen. Lower 2D:4D has been reported for lesbians compared to heterosexuals, but links to high 2D:4D in gay men are less clear. The largest study thus far (the BBC Internet study) found no significant difference between the 2D:4D of lesbians and heterosexual women but a higher 2D:4D in gay men compared to heterosexual men. Here we consider the possibility that low and high prenatal androgen is associated with same-sex attraction in men (n = 108,779) and women (n = 87,742), resulting in more than two phenotypes. We examined the associations between 2D:4D, Dr-l, and same-sex attraction scores in the BBC Internet study. In contrast to the earlier report, which considered sexual orientation in categories, there were positive linear associations in men (right and left 2D:4D, but not Dr-l) and negative linear associations in women (right 2D:4D and Dr-l, but not left 2D:4D). There were no curvilinear relationships for right and left 2D:4D. However, Dr-l showed a U-shaped association with same-sex attraction in men. Thus, (1) high prenatal androgen may be implicated in female homosexuality, while both low and high prenatal androgen may be implicated in male homosexuality, and (2) large side differences in sensitivity to androgen may be associated with elevated same-sex attraction in men.

Direct and radiographic digit ratio (2D:4D) measurements of Tuvan children and adolescents from Southern Siberia: Sex differences and skeletal maturation.

BACKGROUND: In Mongolian-origin ethnic groups digit ratio (2D:4D; a proxy for prenatal sex-steroids) is sexually dimorphic (males < females), as reported for other ethnicities. Most studies measured 2D:4D from soft tissue (directly from the digits, or indirectly from hand scans), or from radiographs. Evidence on the correspondence of 2D:4D measurements from soft tissue with measurements from radiographic images is scarce and has not been reported for a Mongolian-origin sample. In addition, previous research has not considered relationships between 2D:4D and measures of skeletal maturity. AIM: To examine (i) associations between 2D:4D measured directly from the palms with those obtained from radiographic images of the same individuals in a sample of children and adolescents from the Tuvan population in Siberia (Russian Federation), and ii) associations between 2D:4D measurements with chronological and skeletal age. SUBJECTS AND METHODS: Participants were Tuvan boys and girls aged 7 to 18 years. 2D:4D of the right and left hand was measured from soft tissue (directly from the palm) and compared with radiographic images (left hand only). In addition to finger length 2D:4D, we examined 2D:4D of the phalanges from measurements of radiographs. Skeletal age was assessed using the Tanner-Whitehouse method. RESULTS: Sex differences (boys < girls) in measurements of 2D:4D from soft tissue and radiographs were found for total finger length and phalanges. In addition, 2D:4D measurements from radiographs correlated positively and significantly with those obtained from soft tissue. Sex predicted 2D:4D measurements from soft tissue and radiographs, but no effects of chronological/skeletal age and body height were detected. In girls (but not in boys), earlier skeletal maturity (relative to chronological age) was associated with higher 2D:4D in soft tissue measurements of both hands, radiographic 2D:4D, and 2D:4D of the proximal phalanges. CONCLUSION: Consistent with reports from other ethnic groups, 2D:4D in young Tuvans was sexually dimorphic, with boys having lower 2D:4D than girls. For girls, higher 2D:4D was found for participants whose skeletal age was more advanced than chronological age. This finding was obtained from direct soft tissue and indirect radiographic measurements. Age and body height were not associated with 2D:4D, which suggests differences in hormone developmental trajectories for 2D:4D and height.

Predictors of female age, health and attractiveness perception from skin feature analysis of digital portraits in five ethnic groups.

OBJECTIVE: Research indicates the impact of skin colour, tone evenness and surface topography on ratings of age, health and attractiveness in women. In addition to subjective assessments, these effects have been quantified with objective measures derived from skin image analysis. Signs of skin ageing may manifest differently across ethnic groups. However, comparisons have been limited to research with two ethnic groups, preventing conclusions about an ethnicity-specific ranking of skin ageing signs. METHODS: We report results from a multi-ethnic and multi-centre study in which faces of women (n = 180; aged 20-69 years) from five ethnic groups were imaged. Facial images were rated for age, health and attractiveness by members of the same ethnic group (each n = 120). Digital image analysis was used to quantify skin colour, gloss, tone evenness and wrinkling/sagging. We assessed associations between face ratings and skin image measurements in the total sample (i.e. all ethnic groups) and separately by ethnicity. RESULTS: Skin image analysis revealed differences between ethnic groups, including skin colour, gloss, tone evenness, wrinkling and sagging. Differences in the relative predictive utility of individual skin features in accounting for ratings of age, health and attractiveness also were observed between ethnic groups. Facial wrinkling and sagging were the best predictors of face ratings in each ethnic group, with some differences in the type (or predictive magnitude) of skin features. CONCLUSION: The current findings corroborate previous reports of differences between ethnic groups in female facial skin and indicate differential effects of skin features on ratings of age, health and attractiveness, within and between ethnic groups. Facial wrinkling and sagging were the best predictors of age and attractiveness ratings, and skin tone evenness and gloss had an additional role in ratings of health.

OBJECTIF: La présente étude montre l'impact de la couleur de la peau, de l'uniformité du teint, et de la texture cutanée sur l'évaluation de l'âge, de la santé et de l'attractivité chez les femmes. En plus d'évaluations subjectives, ces aspects ont été quantifiés à l'aide de mesures objectives provenant d'analyse d'image de la peau. Les signes de vieillissement de la peau peuvent se manifester différemment selon les groupes ethniques. Cependant, les précédentes recherches se limitent à des comparaisons entre deux groupes ethniques, empêchant ainsi de conclure sur un classement des signes de vieillissement cutané par ethnie. MÉTHODE: Nous présentons les résultats d'une étude multiethnique et multicentrique dans laquelle des visages de femmes (n = 180 ; âgées de 20 à 69 ans) de cinq groupes ethniques ont été imagés. Les images des visages ont été évaluées en termes d'âge, de santé et d'attractivité par des membres du même groupe ethnique (n = 120 par groupe). Des algorithmes d'analyse d'image ont été utilisés pour quantifier la couleur de la peau, la brillance, l'uniformité du teint et les rides/affaissement de la peau. Nous avons analysé les corrélations entre l'évaluation des visages et les mesures quantitatives issues de l'analyse d'image sur la totalité de l'échantillon (c'est-à-dire tous les groupes ethniques) et séparément par ethnie. RÉSULTATS: L'analyse d'image a révélé des différences entre les groupes ethniques, notamment en ce qui concerne la couleur de la peau, la brillance, l'uniformité du teint, les rides et le relâchement cutané. Des différences dans la valeur prédictive relative des différentes caractéristiques cutanées dans l'évaluation de l'âge, de la santé et de l'attractivité ont également été observées entre les groupes ethniques. Les rides et l'affaissement du visage ressortent comme les meilleurs prédicteurs de l'évaluation pour tous les groupes ethniques, avec quelques différences dans le type (ou l'ampleur de la prédiction) des différentes caractéristiques cutanées. CONCLUSION: Les résultats actuels corroborent les rapports précédents sur les différences entre les groupes ethniques concernant la peau du visage des femmes. Ils montrent également des effets différentiels des caractéristiques cutanées sur l'évaluation de l'âge, de la santé et de l'attractivité, au sein des groupes ethniques et entre eux. Les rides et l'affaissement du visage ressortent comme les meilleurs prédicteurs de l'âge et de l'attractivité, tandis que l'uniformité et la brillance du teint jouent un rôle supplémentaire dans l'évaluation de la santé.

Perception of strength, attractiveness and aggressiveness of Maasai male faces calibrated to handgrip strength: Evidence from a European sample.

OBJECTIVES: Previous research showed that male and female members of the Maasai from Northern Tanzania judge images of facial morphs calibrated to greater handgrip strength (HGS) higher on strength and attractiveness, but lower on aggressiveness than those calibrated to lower HGS. The accurate assessment of male physical strength from facial information may be adaptive as suggested by the evidence on health and fitness-related benefits linked to high muscular strength. METHODS: This study extends previous work by obtaining European female (n = 220) and male (n = 51) assessments of HGS-calibrated Maasai male faces. Participants rated five facial morphs for strength, attractiveness, and aggressiveness on computer screens. RESULTS: Perceived physical strength increased with morphs calibrated to higher HGS. The lowest and highest HGS morphs were judged lower in attractiveness than the others, and rated aggressiveness decreased in morphs calibrated to higher HGS. CONCLUSIONS: Given the high similarity between the current study findings and those previously reported from intra-population assessments of Maasai faces calibrated to HGS, we suggest that strength and aggressiveness perceptions of facial features associated with male physical strength may be universal. Attractiveness assessments of strength-related information in the faces of (very) strong men were less consistent across populations, possibly attributable to cultural and ecological contexts.

Parental Income and the Sexual Behavior of Their Adult Children: A Trivers-Willard Perspective.

Parental income is negatively and linearly related to the digit ratio (2D:4D; a proxy for prenatal sex steroids) of their children. Children of parents with high income are thought to be exposed to higher prenatal testosterone and develop lower 2D:4D. It is further hypothesized that 2D:4D relates to sexual orientation, although it is unclear whether the association is linear or curvilinear. Here, we consider patterns of parental income and its association with the sexual behavior of their adult children in a large online study (the BBC internet study). There were curvilinear relationships with parental income in male and female children. The highest frequencies of homosexuality and bisexuality were found in the lowest income group (bottom 25% of the population), the lowest frequencies in the income group representing the upper 50% of the population, and intermediate values in the other groups (low 50% and top 25% of the population). Parental income showed a U-shaped association with scores for same-sex attraction and an inverted U-shaped association with opposite-sex attraction. Thus, for the first time, we show that same-sex attraction is related to parental income. The curvilinear relationship between parental income and sexual behavior in their adult children may result from an association between very high fetal estrogen or testosterone and attraction to partners of the same sex. Among non-heterosexuals, and in both sexes, very high fetal estrogen may be associated with femme or submissive sexual roles, and very high fetal testosterone with butch and assertive sexual roles.

Mate Retention Behavior and Ejaculate Quality in Humans.

Males of some species use mate retention behavior and investment in ejaculate quality as anti-cuckoldry tactics concurrently while others do so in a compensatory fashion. Leivers, Rhodes, and Simmons (2014) reported that men who performed mate retention less frequently produced higher-quality ejaculates, suggesting that humans use these tactics compensatorily. We conducted a conceptual replication of this research in a sample of 41 men (18-33 years; M = 23.33; SD = 3.60). By self-report, participants had not had a vasectomy and had never sought infertility treatment. We controlled for several covariates known to affect ejaculate quality (e.g., abstinence duration before providing an ejaculate) and found no statistically significant relationships between mate retention behavior and four components of ejaculate quality: sperm velocity, sperm concentration, slow motility, and ejaculate volume. The present results provide little support for the hypothesis that human males deploy mate retention behavior and ejaculate quality investment compensatorily. We discuss the limitations of this study and highlight the need for research to address questions about the nature of anti-cuckoldry tactic deployment in humans, especially concerning investment in ejaculate quality.

Differences between perceived age and chronological age in women: A multi-ethnic and multi-centre study.

OBJECTIVE: Accuracy in assessing age from facial cues is important in social perception given reports of strong negative correlations between perceived age and assessments of health and attractiveness. In a multi-ethnic and multi-centre study, we previously documented similar patterns of female facial age assessments across ethnicities, influenced by gender and ethnicity of assessors. METHODS: Here we extend these findings by examining differences between estimated age from digital portraits and chronological age (Δ age) for 180 women from three age groups (20-34, 35-49, 50-66 years) and five ethnicities (36 images of each ethnicity, assessed for age on a continuous scale by 120 female and male raters of each ethnicity). RESULTS: Across ethnicities, Δ age was smallest in French assessors and largest in South African assessors. Numerically, French women were judged oldest and Chinese women youngest relative to chronological age. In younger women, Δ age was larger than in middle-aged and older women. This effect was particularly evident when considering the interaction of women's age with assessor gender and ethnicity, independently and together, on Δ age. CONCLUSION: Collectively, our findings suggest that accuracy in assessments of female age from digital portraits depends on the chronological age and ethnicity of the photographed women and the ethnicity and gender of the assessor. We discuss the findings concerning ethnic variation in skin pigmentation and visible signs of ageing and comment on implications for cosmetic science.

OBJECTIF: La capacité à évaluer l'âge d'un visage avec exactitude en fonction de ses caractéristiques est important dans sa perception sociale. En effet, des corrélations négatives fortes ont été rapportées entre l'âge perçu d'un visage d'une part, et sa santé et attractivité d'autre part. Dans le cadre d'une étude multi-ethnique et multicentrique, nous avons déjà documenté, dans une démarche similaire, comment la perception de l'âge de visages féminins entre différentes populations, est influencée par le genre et l'origine des évaluateurs. METHODES: Ici nous approfondissons ces premiers résultats par l'étude des différences entre l'âge estimé sur portraits numériques de 180 femmes issues de 3 groupes d'âges (20-34, 35-49, 50-66 ans) et de 5 populations d'origine différente (36 images de chaque population) et leur âge réel (Δ âge), et ce par 120 évaluatrices et évaluateurs de chaque population évaluant l'âge des visages en utilisant une échelle continue. RESULTATS: Au sein des différentes populations d'évaluateurs, le Δ âge le plus faible a été trouvé chez les évaluateurs français et le plus élevé chez les évaluateurs sud-africains. Sur portraits numériques, les femmes françaises ont été perçues comme étant les plus âgées et les femmes chinoises les plus jeunes, par rapport à leur âge réel. Chez les femmes les plus jeunes, le Δ âge a été plus élevé que chez les femmes d'âge moyen et les plus âgées. Ceci a particulièrement été le cas lorsque l'on considère les interactions entre l'âge des femmes évaluées, et le genre et l'origine des évaluateurs, de façon indépendante ou liée, avec le Δ âge. CONCLUSION: Aux travers des différentes analyses, nos résultats suggèrent que l'exactitude avec laquelle l'âge des femmes est évalué sur images numériques de leur visage, dépend de l'âge réel et de l'origine de ces femmes photographiées, ainsi que de l'origine est du genre de l'évaluateur. Nous discutons ces résultats en regard des variations de pigmentation cutanée et de signes visibles de l'âge entre les différentes populations et commentons les implications possibles pour les sciences cosmétiques.

Cross-cultural perception of female facial appearance: A multi-ethnic and multi-centre study.

Humans extract and use information from the face in assessments of physical appearance. Previous research indicates high agreement about facial attractiveness within and between cultures. However, the use of a narrow age range for facial stimuli, limitations due to unidirectional cross-cultural comparisons, and technical challenges have prevented definitive conclusions about the universality of face perception. In the present study, we imaged the faces of women aged 20 to 69 years in five locations (China, France, India, Japan, and South Africa) and secured age, attractiveness, and health assessments on continuous scales (0-100) from female and male raters (20-66 years) within and across ethnicity. In total, 180 images (36 of each ethnicity) were assessed by 600 raters (120 of each ethnicity), recruited in study centres in the five locations. Linear mixed model analysis revealed main and interaction effects of assessor ethnicity, assessor gender, and photographed participant ("face") ethnicity on age, attractiveness, and health assessments. Thus, differences in judgments of female facial appearance depend on the ethnicity of the photographed person, the ethnicity of the assessor, and whether the assessor is female or male. Facial age assessments correlated negatively with attractiveness and health assessments. Collectively, these findings provide evidence of cross-cultural variation in assessments of age, and even more of attractiveness, and health, indicating plasticity in perception of female facial appearance across cultures, although the decline in attractiveness and health assessments with age is universally found.

Are There Differences in Experts' and Lay Assessors' Attractiveness Judgments of Non-Professional Men's Dance/Gait Movements?

Research on attractiveness assessments of men's dance has shown that raters derive and integrate information about male mating-related qualities into their attractiveness assessments, but prior studies have focused on lay assessors (i.e., individuals with no professional dance background) rather than dance experts. We recruited male and female Russian dance experts (n = 23) to judge gender-neutral, featureless virtual characters, animated with motion-captured dance movements and gaits of British men, and compared their dance assessments to those from a group of Russian male and female lay assessors (n = 73). The dance experts provided higher dance and gait attractiveness judgments than the lay assessors. Both groups judged the gait movements to be of higher attractiveness than the dance movements. Differences in attractiveness assessments between experts and lay assessors were larger for the male judges than for the female judges. In an additional survey, the dance experts (versus lay assessors) placed greater emphasis on the importance of dance-related capacities and skills. We discuss our findings with reference to past research on dance/gait attractiveness as assessed by lay judges and the role of expertise in assessing body movement.

Understanding COVID-19: A hypothesis regarding digit ratio (2D:4D), ACE I/D polymorphism, oxygen metabolism and national case fatality rates.

OBJECTIVE: Male digit ratio (2D:4D) correlates positively with the national case fatality rate (CFR) for COVID-19. The severity of COVID-19 may be influenced by a counterbalance between the angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2). SARS-CoV2 cleaves with ACE2 and enters cells leaving an unopposed effect of ACE in the lungs. Both 2D:4D and the ACE I/D polymorphism are covariates of oxygen metabolism. COVID-19 leads to lung damage and a reduction in oxygen saturation of the blood. Here, we examine the interrelationships between 2D:4D, ACE polymorphism, and COVID-19 CFR. METHODS: National frequencies/rates were obtained for 2D:4D from the BBC Internet study (n = 41), published values of ACE I/II (n = 39), and COVID-19 CFR from three World Health Organization situation reports (n = 41). RESULTS: 2D:4D was negatively associated with national ACE I/II frequencies. However, there was a positive relationship between male 2D:4D and CFR (right and left 2D:4D, two, and three situation reports respectively). The relationships between ACE I/II and CFR were non-significant. Relationships between male 2D:4D and CFR's were independent of female 2D:4D and ACE I/II. CONCLUSIONS: The ACE I/D polymorphism may influence 2D:4D such that ACE II individuals have lower 2D:4D than ACE DD individuals. Low 2D:4D and ACE II individuals show efficient oxygen metabolism. Therefore, low 2D:4D and ACE II together may protect against COVID-19 severity. The sex-dependent positive correlation between male 2D:4D and CFR is independent of ACE I/II, suggesting that the sex-dependent variation in the ACE2 gene may also influence the 2D:4D phenotype.

No Evidence for a Relationship between Intelligence and Ejaculate Quality.

Genetic quality may be expressed through many traits simultaneously, and this would suggest a phenotype-wide fitness factor. In humans, intelligence has been positively associated with several potential indicators of genetic quality, including ejaculate quality. We conducted a conceptual replication of one such study by investigating the relationship between intelligence (assessed by the Raven Advanced Progressive Matrices Test-Short Form) and ejaculate quality (indexed by sperm count, sperm concentration, and sperm motility) in a sample of 41 men (ages ranging 18 to 33 years; M = 23.33; SD = 3.60). By self-report, participants had not had a vasectomy, and had never sought infertility treatment. We controlled for several covariates known to affect ejaculate quality (e.g., abstinence duration before providing an ejaculate) and found no statistically significant relationship between intelligence and ejaculate quality; our findings, therefore, do not match those of Arden, Gottfredson, Miller et al. or those of previous studies. We discuss limitations of this study and the general research area and highlight the need for future research in this area, especially the need for larger data sets to address questions around phenotypic quality and ejaculate quality.

No Evidence for a Trade-Off Between Competitive Traits and Ejaculate Quality in Humans.

Research in nonhuman animals (including insects, birds, and primates) suggests a trade-off in males between investment in competitive traits and investment in ejaculate quality. Previous research reported a negative association between perceived strength and ejaculate quality, suggesting that this trade-off also applies to human males. We conducted novel analyses of data secured as part of a larger project to assess the relationship between competitive traits (shoulder-to-hip ratio, handgrip strength, and height) and ejaculate quality (indexed by sperm morphology, sperm motility, and sperm concentration) in a sample of 45 men (ages ranging 18-33 years; M = 23.30, SD = 3.60). By self-report, participants had not had a vasectomy and had never sought treatment for infertility. We controlled for several covariates known to affect ejaculate quality (e.g., abstinence duration before providing an ejaculate) and found no statistically significant relationships between competitive traits and ejaculate quality; our findings therefore do not accord with previous research on humans. We highlight the need for additional research to clarify whether there is a trade-off between investment in competitive traits and investment in ejaculate quality in humans.

Understanding COVID-19: Digit ratio (2D:4D) and sex differences in national case fatality rates.

BACKGROUND: The reported national case fatality rates (CFRs) for coronavirus disease 2019 (COVID-19) shows a sex bias with males > females. The relative lengths of the index (2D) and ring (4D) fingers (digit ratio; 2D:4D) is a sexually dimorphic (males < females) proxy of fetal sex steroids (low 2D:4D indicates high prenatal testosterone/low prenatal estrogen). AIM: To examine sex-specific relationships of 2D:4D per nation with national values of COVID-19 CFRs. STUDY DESIGN: COVID-19 CFRs and the percent of male deaths were related to mean national (self-reported) 2D:4D by sex and hand from a large online survey (the BBC Internet Study). SUBJECTS: 103,482 men and 83,366 women. OUTCOME MEASURES: Relationships of mean national 2D:4D with CFRs from 41 countries and with national male death rates from 16 countries. RESULTS: Male right and left hand 2D:4D showed positive relationships with CFR. These relationships remained significant after removing the influence of female 2D:4D. A positive association of male right and left 2D:4D was detected with the percentage of male deaths. CONCLUSIONS: At the national level, high mean 2D:4D (indicating low prenatal testosterone/high prenatal estrogen) is associated with high CFRs and percent male mortality. At the individual level, high 2D:4D may be a risk factor for severity of COVID-19 in males. We speculate that male 2D:4D is a negative correlate for expression of the SARS-CoV2 receptor (ACE2).

Improvement of Radial Cheek Lines With Hyaluronic Acid-Based Dermal Filler VYC-17.5L: Results of the BEAM Study.

BACKGROUND: Radial cheek lines (RCL) may convey an older, potentially less attractive appearance. OBJECTIVE: To evaluate the effectiveness of hyaluronic acid-based dermal filler VYC-17.5L for correcting RCL. MATERIALS AND METHODS: Fifty-three women (40-65 years) received injections of VYC-17.5L in both cheeks on Day 1 (optional Day 14 touch-up). Effectiveness was evaluated on Day 45 by subject-rated dynamic RCL improvement (Global Aesthetic Improvement Scale [GAIS]; primary end point) and independent, noninjecting investigator-rated GAIS; subject Self-Perception of Age (SPA); subject-assessed satisfaction with and natural look of treatment; and instrument-assessed changes in static and dynamic RCL roughness, amplitude, and texture (secondary end points). Safety assessments included injection site responses (ISRs). RESULTS: On Day 45, 98% of subjects rated RCL as improved or much improved (investigator rated: 95%). Subjects with same or older SPA before treatment (n = 38) perceived themselves as 2.0 and 5.5 average years younger after treatment, respectively. Day 45 mean satisfaction with and natural look of treated areas was 7.9/10 and 7.2/10, respectively. Treatment significantly improved RCL roughness, amplitude, and texture (all p < .001). Most common ISRs were hematoma (35.9%), bruising (30.2%), and irregularities/bumps (22.6%); most ISRs were mild. CONCLUSION: VYC-17.5L effectively corrected dynamic RCL, improved instrument-assessed indicators of skin quality, and resulted in younger age perception.

Assessment of physical strength from gait: data from the Maasai of Tanzania.

In industrialized societies, male gait provides information about physical strength. Male physical strength may be used by men and women to assess the fighting ability of rivals and the quality of potential mates, respectively. Women more than men discriminate between strong and weak walkers when assessing gait attractiveness. We presented videos of British men's gait-pre-categorized into strong and weak walkers-to male and female members ( n = 100) of the traditional Maasai in northern Tanzania in Africa. Maasai men and women judged the gaits of physically strong men less attractive than those of weak men and judged strong walkers to be weaker than weak walkers. These findings counter results from industrialized societies where participants accurately assessed strength from gait, thus arguing against a universal perception of physical strength from gait information.