1
|
Pokorný Š, Pavlovič O, Kleisner K. Sexual Dimorphism: The Interrelation of Shape and Color. ARCHIVES OF SEXUAL BEHAVIOR 2024; 53:3255-3265. [PMID: 38944665 PMCID: PMC11335828 DOI: 10.1007/s10508-024-02918-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 07/01/2024]
Abstract
Sex-typicality displayed as sexual dimorphism of the human face is a key feature enabling sex recognition. It is also believed to be a cue for perceiving biological quality and it plays an important role in the perception of attractiveness. Sexual dimorphism of human faces has two main components: sexual shape dimorphism of various facial features and sexual color dimorphism, generally manifested as dimorphism of skin luminance, where men tend to be darker than women. However, very little is known about the mutual relationship of these two facets. We explored the interconnection between the dimorphism of face shape and dimorphism of face color in three visually distinct populations (Cameroonian, Czech, and Vietnamese). Our results indicated that populations which showed a significant dimorphism in skin luminance (Cameroon, Vietnam) had low levels of sexual shape dimorphism, while a population with higher levels of sexual shape dimorphism (Czech Republic) did not exhibit a significant dimorphism of skin luminance. These findings suggest a possible compensatory mechanism between various domains of sexual dimorphism in populations differing in the levels of shape and color dimorphism.
Collapse
Affiliation(s)
- Šimon Pokorný
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Albertov 6, 128 00, Prague, Czech Republic.
| | - Ondřej Pavlovič
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Albertov 6, 128 00, Prague, Czech Republic
| | - Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Albertov 6, 128 00, Prague, Czech Republic
| |
Collapse
|
2
|
Martínez-Ramírez J, Puts D, Nieto J, G-Santoyo I. Effects of facial skin pigmentation on social judgments in a Mexican population. PLoS One 2023; 18:e0279858. [PMID: 38032952 PMCID: PMC10688750 DOI: 10.1371/journal.pone.0279858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 10/12/2023] [Indexed: 12/02/2023] Open
Abstract
People quickly and involuntarily form impressions of others based on their facial physical attributes, which can modulate critical social interactions. Skin pigmentation is one of the most variable and conspicuous facial traits among human populations. Empirical evidence suggests that these variations reflect ancestral ecological selective pressures balancing cutaneous vitamin D synthesis with the protection of the dermis from ultraviolet radiation. Nevertheless, skin pigmentation may currently be subject to additional selective pressures. For instance, the colonial era in Central and South America developed a highly stratified society based on ethnic origins, and light skin pigmentation became associated with higher social status and deference. This association could have originated through historical social learning that promoted favorable social perceptions towards individuals with lighter skin color and unfavorable perceptions towards individuals with darker skin color, which could still be present in the perception of current populations. Facial skin pigmentation is also sexually dimorphic, with males tending to exhibit darker skin than females, a difference that could be driven by sexual selection. To explore whether social learning and sexual selection represent additional selective pressures on skin pigmentation, we tested how this facial trait influences fundamental social perceptions in a Mexican population (N = 700, 489 female). We sampled facial images of eight European American males with natural lighter facial skin and eight males from an indigenous pre-Columbian community from Mexico, the Me'Phaa, with natural darker facial skin. We produced stimuli from these images by varying the skin pigmentation while preserving the facial shape. Stimuli were rated on attractiveness, trustworthiness, perceived health, dominance, aggressiveness, and femininity/masculinity. We found that the natural light-skinned faces were perceived as more attractive, trustworthy, and healthy but less dominant than the natural dark faces. Furthermore, by varying the facial skin color in these original groups, we altered the perceptions of them, mainly their attractiveness. These results partially support the hypothesis that dark facial skin color may help males compete for mates. Also, the results strongly support the view that lighter facial skin color became associated with social benefits through social learning in this Mexican population. Our findings, when viewed through the lens of cultural evolution, align with previous research in social psychology and anthropology. They hold the potential to offer a comprehensive understanding of the origin of this social phenomenon of cultural transmission, which currently plays a role in the formation of racial attitudes, stereotyping, and racial inequality in Mexican and other Latin American populations.
Collapse
Affiliation(s)
- Jaaziel Martínez-Ramírez
- Faculty of Psychology, Neuroecology Laboratory, National Autonomous University of Mexico, Mexico City, Mexico
| | - David Puts
- Department of Anthropology and Center for Human Evolution and Diversity, The Pennsylvania State University, University Park, College Township, Pennsylvania, United States of America
| | - Javier Nieto
- Faculty of Psychology, Laboratory of Learning and Adaptation, National Autonomous University of Mexico, Mexico City, Mexico
| | - Isaac G-Santoyo
- Faculty of Psychology, Neuroecology Laboratory, National Autonomous University of Mexico, Mexico City, Mexico
- Unidad de Investigación en Psicobiología y Neurociencias, National Autonomous University of Mexico, Mexico City, Mexico
| |
Collapse
|
3
|
Pazhoohi F, Kingstone A. Eyelash length attractiveness across ethnicities. Sci Rep 2023; 13:14849. [PMID: 37684317 PMCID: PMC10491613 DOI: 10.1038/s41598-023-41739-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
Eyelashes evolved to protect eyes. An optimum eyelash length functions to protect eyes from external hazards such as contaminations, excessive evaporation or shear stress from airflow. They can also be an indicator of a person's health as various congenital and noncongenital diseases can lead to short or long eyelashes. The current study aimed to extend a recent investigation on the preference for eyelash length in humans from an evolutionary adaptive perspective. Specifically, the current study tested whether the inverted-U function for eyelash length preference recently reported for White faces, generalises to other ethnicities, and whether ethnic background modulates preference for eyelash lengths. To investigate this question, men and women of Asian, Black, and White ethnicities from the U.S. rated the attractiveness of female Indian, Asian, Black, and White faces with varying eyelash lengths. The eyelashes ranged in length from no eyelashes to half the width of an eye. Results showed that Asian, Black, and White men and women preference for eyelash length followed an inverted-U function across all four ethnicities, supporting a general preference for human eyelash length that is approximately one-third the width of an eye. In addition, the results showed that the most attractive eyelashes for Black women were skewed toward a greater eyelash-length to eye-width ratio when compared to the other images. The source of this skew is presently unknown, as it could reflect a change in perceptual sensitivity to eyelash length with skin colour or changes in preference related to perceptions of participants' ethnicity.
Collapse
Affiliation(s)
- Farid Pazhoohi
- School of Psychology, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK.
| | - Alan Kingstone
- Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, V6T 1Z4, Canada.
| |
Collapse
|
4
|
Wilson VAD, Masilkova M. Does the primate face cue personality? PERSONALITY NEUROSCIENCE 2023; 6:e7. [PMID: 38107779 PMCID: PMC10725780 DOI: 10.1017/pen.2023.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/24/2023] [Accepted: 05/31/2023] [Indexed: 12/19/2023]
Abstract
When looking at others, primates primarily focus on the face - detecting the face first and looking at it longer than other parts of the body. This is because primate faces, even without expression, convey trait information crucial for navigating social relationships. Recent studies on primates, including humans, have linked facial features, specifically facial width-to-height ratio (fWHR), to rank and Dominance-related personality traits, suggesting these links' potential role in social decisions. However, studies on the association between dominance and fWHR report contradictory results in humans and variable patterns in nonhuman primates. It is also not clear whether and how nonhuman primates perceive different facial cues to personality traits and whether these may have evolved as social signals. This review summarises the variable facial-personality links, their underlying proximate and evolutionary mechanisms and their perception across primates. We emphasise the importance of employing comparative research, including various primate species and human populations, to disentangle phylogeny from socio-ecological drivers and to understand the selection pressures driving the facial-personality links in humans. Finally, we encourage researchers to move away from single facial measures and towards holistic measures and to complement perception studies using neuroscientific methods.
Collapse
Affiliation(s)
- Vanessa A D Wilson
- Department of Comparative Cognition, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
- Department of Comparative Language Science, University of Zurich, Zurich, Switzerland
- Center for the Interdisciplinary Study of Language Evolution (ISLE), University of Zurich, Zurich, Switzerland
| | - Michaela Masilkova
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| |
Collapse
|
5
|
Pátková Ž, Schwambergová D, Třebická Fialová J, Třebický V, Stella D, Kleisner K, Havlíček J. Attractive and healthy-looking male faces do not show higher immunoreactivity. Sci Rep 2022; 12:18432. [PMID: 36319732 PMCID: PMC9626598 DOI: 10.1038/s41598-022-22866-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 10/20/2022] [Indexed: 01/01/2023] Open
Abstract
Previous research has indicated that facial attractiveness may provide cues to the functioning of the immune system. Mating with individuals who have a more effective immune system could lead to a higher reproductive success. Our main aim was to test a possible association between immunoreactivity (stimulated by vaccination) and perceived facial attractiveness and healthiness. We experimentally activated the immune system of healthy men using vaccination against hepatitis A/B and meningococcus and measured levels of specific antibodies (markers of immune system reactivity) before and 30 days after the vaccination. Further, 1 day before the vaccination, we collected their facial photographs that were judged by females for attractiveness, healthiness, and facial skin patches for healthiness. In view of its proposed connection with the functioning of the immune system, we also measured skin colouration (both from the facial photographs and in vivo using a spectrophotometer) and we assessed its role in attractiveness and healthiness judgements. Moreover, we measured the levels of steroid hormones (testosterone and cortisol) and the percentage of adipose tissue, because both are known to have immunomodulatory properties and are related to perceived facial attractiveness and healthiness. We found no significant associations between antibody levels induced by vaccination and perceived facial attractiveness, facial healthiness, or skin healthiness. We also found no significant connections between steroid hormone levels, the amount of adipose tissue, rated characteristics, and antibody levels, except for a small negative effect of cortisol levels on perceived facial healthiness. Higher forehead redness was perceived as less attractive and less healthy and higher cheek patch redness was perceived as less healthy, but no significant association was found between antibody levels and facial colouration. Overall, our results suggest that perceived facial attractiveness, healthiness, and skin patch healthiness provide limited cues to immunoreactivity, and perceived characteristics seem to be related only to cortisol levels and facial colouration.
Collapse
Affiliation(s)
- Žaneta Pátková
- Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic.
| | - Dagmar Schwambergová
- Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic
| | | | - Vít Třebický
- Faculty of Physical Education and Sport, Charles University, José Martího 269, 162 52, Prague, Czech Republic
| | - David Stella
- Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic
- Global Change Research Institute of the Czech Academy of Sciences, Bělidla 986/4a, 603 00, Brno, Czech Republic
| | - Karel Kleisner
- Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic
| | - Jan Havlíček
- Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic
| |
Collapse
|
6
|
Farrera A. Formal models for the study of the relationship between fluctuating asymmetry and fitness in humans. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 179:73-84. [PMID: 36790746 PMCID: PMC9540978 DOI: 10.1002/ajpa.24588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/04/2022] [Accepted: 06/20/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To evaluate three of the main verbal models that have been proposed to explain the relationship between fluctuating asymmetry and fitness in humans: the "good genes," the "good development," and the "growth" hypotheses. MATERIALS AND METHODS A formal model was generated for each verbal model following three steps. First, based on the literature, a theoretical causal model and the theoretical object of inquiry were outlined. Second, an empirical causal model and the targets of inference were defined using observational data of facial asymmetries and life-history traits related to fitness. Third, generalized linear models and causal inference were used as the estimation strategy. RESULTS The results suggest that the theoretical and empirical assumptions of the "good genes" hypothesis should be reformulated. The results were compatible with most of the empirical assumptions of "the good development" hypothesis but suggest that further discussion of its theoretical assumptions is needed. The results were less informative about the "growth" hypothesis, both theoretically and empirically. There was a positive association between facial fluctuating asymmetry and the number of offspring that was not compatible with any of the empirical causal models evaluated. CONCLUSIONS Although the three hypotheses focus on different aspects of the link between asymmetry and fitness, their overlap opens the possibility of a unified theory on the subject. The results of this study make explicit which assumptions need to be updated and discussed, facilitating the advancement of this area of research. Overall, this study elucidates the potential benefit of using formal models for theory revision and development.
Collapse
Affiliation(s)
- Arodi Farrera
- Mathematical Modeling of Social Systems Department, Institute for Research on Applied Mathematics and Systems, National Autonomous University of Mexico, Mexico City, Mexico
| |
Collapse
|
7
|
Romantic feedbacks influence self-relevant processing: the moderating effects of sex difference and facial attractiveness. CURRENT PSYCHOLOGY 2022. [DOI: 10.1007/s12144-021-02114-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
8
|
Fiala V, Tureček P, Akoko RM, Pokorný Š, Kleisner K. Africans and Europeans differ in their facial perception of dominance and sex-typicality: a multidimensional Bayesian approach. Sci Rep 2022; 12:6821. [PMID: 35474334 PMCID: PMC9042949 DOI: 10.1038/s41598-022-10646-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 04/12/2022] [Indexed: 01/27/2023] Open
Abstract
Biosocial impact of facial dominance and sex-typicality is well-evidenced in various human groups. It remains unclear, though, whether perceived sex-typicality and dominance can be consistently predicted from sexually dimorphic facial features across populations. Using a combination of multidimensional Bayesian approach and geometric morphometrics, we explored associations between perceived dominance, perceived sex-typicality, measured sexual shape dimorphism, and skin colour in a European and an African population. Unlike previous studies, we investigated the effect of facial variation due to shape separately from variation due to visual cues not related to shape in natural nonmanipulated stimuli. In men, perceived masculinity was associated with perceived dominance in both populations. In European women higher perceived femininity was, surprisingly, likewise positively associated with perceived dominance. Both shape and non-shape components participate in the constitution of facial sex-typicality and dominance. Skin colour predicted perceived sex-typicality in Africans but not in Europeans. Members of each population probably use different cues to assess sex-typicality and dominance. Using our methods, we found no universal sexually dimorphic scale predicting human perception of sex-typicality and dominance. Unidimensional understanding of sex-typicality thus seems problematic and should be applied with cautions when studying perceived sex-typicality and its correlates.
Collapse
Affiliation(s)
- Vojtěch Fiala
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic.
| | - Petr Tureček
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic
- Center for Theoretical Study, Charles University and Czech Academy of Sciences, Prague, Czech Republic
| | - Robert Mbe Akoko
- Department of Communication and Development Studies, University of Bamenda, Bamenda, Cameroon
| | - Šimon Pokorný
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic
| | - Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44, Prague, Czech Republic
| |
Collapse
|
9
|
Butovskaya ML, Rostovtseva VV, Mezentseva AA. Facial and body sexual dimorphism are not interconnected in the Maasai. J Physiol Anthropol 2022; 41:3. [PMID: 34996526 PMCID: PMC8740871 DOI: 10.1186/s40101-021-00276-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/10/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND In this paper, we investigate facial sexual dimorphism and its' association with body dimorphism in Maasai, the traditional seminomadic population of Tanzania. We discuss findings on other human populations and possible factors affecting the developmental processes in Maasai. METHODS Full-face anthropological photographs were obtained from 305 Maasai (185 men, 120 women) aged 17-90 years. Facial shape was assessed combining geometric morphometrics and classical facial indices. Body parameters were measured directly using precise anthropological instruments. RESULTS Sexual dimorphism in Maasai faces was low, sex explained 1.8% of the total shape variance. However, male faces were relatively narrower and vertically prolonged, with slightly wider noses, narrower-set and lower eyebrows, wider mouths, and higher forehead hairline. The most sexually dimorphic regions of the face were the lower jaw and the nose. Facial width-to-height ratio (fWHR), measured in six known variants, revealed no significant sexual dimorphism. The allometric effects on facial traits were mostly related to the face growth, rather than the growth of the whole body (body height). Significant body dimorphism was demonstrated, men being significantly higher, with larger wrist diameter and hand grip strength, and women having higher BMI, hips circumferences, upper arm circumferences, triceps skinfolds. Facial and body sexual dimorphisms were not associated. CONCLUSIONS Facial sex differences in Maasai are very low, while on the contrary, the body sexual dimorphism is high. There were practically no associations between facial and body measures. These findings are interpreted in the light of trade-offs between environmental, cultural, and sexual selection pressures.
Collapse
Affiliation(s)
- Marina L Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, 119334, Russia.
- The National Research University Higher School of Economics, Moscow, 101000, Russia.
- Russian State University for the Humanities, Moscow, 125047, Russia.
| | - Victoria V Rostovtseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Anna A Mezentseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, 119334, Russia
| |
Collapse
|
10
|
Versluys TMM, Flintham EO, Mas-Sandoval A, Savolainen V. Why do we pick similar mates, or do we? Biol Lett 2021; 17:20210463. [PMID: 34813721 DOI: 10.1098/rsbl.2021.0463] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Humans often mate with those resembling themselves, a phenomenon described as positive assortative mating (PAM). The causes of this attract broad interest, but there is little agreement on the topic. This may be because empirical studies and reviews sometimes focus on just a few explanations, often based on disciplinary conventions. This review presents an interdisciplinary conceptual framework on the causes of PAM in humans, drawing on human and non-human biology, the social sciences, and the humanities. Viewing causality holistically, we first discuss the proximate causes (i.e. the 'how') of PAM, considering three mechanisms: stratification, convergence and mate choice. We also outline methods to control for confounders when studying mate choice. We then discuss ultimate explanations (i.e. 'the why') for PAM, including adaptive and non-adaptive processes. We conclude by suggesting a focus on interdisciplinarity in future research.
Collapse
Affiliation(s)
- Thomas M M Versluys
- Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire SL5 7PY, United Kingdom
| | - Ewan O Flintham
- Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire SL5 7PY, United Kingdom
| | - Alex Mas-Sandoval
- Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire SL5 7PY, United Kingdom
| | - Vincent Savolainen
- Georgina Mace Centre for the Living Planet, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire SL5 7PY, United Kingdom
| |
Collapse
|
11
|
Population affinity and variation of sexual dimorphism in three-dimensional facial forms: comparisons between Turkish and Japanese populations. Sci Rep 2021; 11:16634. [PMID: 34404851 PMCID: PMC8371176 DOI: 10.1038/s41598-021-96029-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/28/2021] [Indexed: 11/22/2022] Open
Abstract
Examining the extent to which sex differences in three-dimensional (3D) facial soft tissue configurations are similar across diverse populations could suggest the source of the indirect evolutionary benefits of facial sexual dimorphism traits. To explore this idea, we selected two geographically distinct populations. Three-dimensional model faces were derived from 272 Turkish and Japanese men and women; their facial morphologies were evaluated using landmark and surface-based analyses. We found four common facial features related to sexual dimorphism. Both Turkish and Japanese females had a shorter lower face height, a flatter forehead, greater sagittal cheek protrusion in the infraorbital region but less prominence of the cheek in the parotid-masseteric region, and an antero-posteriorly smaller nose when compared with their male counterparts. The results indicated the possible phylogenetic contribution of the masticatory organ function and morphogenesis on sexual dimorphism of the human face in addition to previously reported biological and psychological characteristics, including sexual maturity, reproductive potential, mating success, general health, immune response, age, and personality.
Collapse
|
12
|
Fiala V, Třebický V, Pazhoohi F, Leongómez JD, Tureček P, Saribay SA, Akoko RM, Kleisner K. Facial attractiveness and preference of sexual dimorphism: A comparison across five populations. EVOLUTIONARY HUMAN SCIENCES 2021; 3:e38. [PMID: 37588529 PMCID: PMC10427909 DOI: 10.1017/ehs.2021.33] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Despite intensive research, evolutionary psychology has not yet reached a consensus regarding the association between sexual dimorphism and attractiveness. This study examines associations between perceived and morphological facial sexual dimorphism and perceived attractiveness in samples from five distant countries (Cameroon, Colombia, Czechia, Iran and Turkey). We also examined possible moderating effects of skin lightness, averageness, age, body mass and facial width. Our results suggest that in all samples, women's perceived femininity was positively related to their perceived attractiveness. Women found perceived masculinity in men attractive only in Czechia and Colombia, two distant populations. The association between perceived sexual dimorphism and attractiveness is thus potentially universal only for women. Across populations, morphological sexual dimorphism and averageness are not universally associated with either perceived facial sexual dimorphism or attractiveness. With our exploratory approach, results highlight the need for control of which measure of sexual dimorphism is used (perceived or measured) because they affect perceived attractiveness differently. Morphological averageness and sexual dimorphism are not good predictors of perceived attractiveness. It is noted that future studies should use samples from multiple populations to allow for identification of specific effects of local environmental and socioeconomic conditions on preferred traits in unmanipulated local facial stimuli.
Collapse
Affiliation(s)
- Vojtěch Fiala
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| | - Vít Třebický
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
- Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic
| | - Farid Pazhoohi
- Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Juan David Leongómez
- Human Behaviour Laboratory, Faculty of Psychology, Universidad El Bosque, Bogota, Colombia
| | - Petr Tureček
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| | - S. Adil Saribay
- Department of Psychology, Kadir Has University, Istanbul, Turkey
| | - Robert Mbe Akoko
- Department of Communication and Development Studies, University of Bamenda, Cameroon
| | - Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| |
Collapse
|
13
|
How and why patterns of sexual dimorphism in human faces vary across the world. Sci Rep 2021; 11:5978. [PMID: 33727579 PMCID: PMC7966798 DOI: 10.1038/s41598-021-85402-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 02/22/2021] [Indexed: 01/31/2023] Open
Abstract
Sexual selection, including mate choice and intrasexual competition, is responsible for the evolution of some of the most elaborated and sexually dimorphic traits in animals. Although there is sexual dimorphism in the shape of human faces, it is not clear whether this is similarly due to mate choice, or whether mate choice affects only part of the facial shape difference between men and women. Here we explore these questions by investigating patterns of both facial shape and facial preference across a diverse set of human populations. We find evidence that human populations vary substantially and unexpectedly in both the magnitude and direction of facial sexually dimorphic traits. In particular, European and South American populations display larger levels of facial sexual dimorphism than African populations. Neither cross-cultural differences in facial shape variation, sex differences in body height, nor differing preferences for facial femininity and masculinity across countries, explain the observed patterns of facial dimorphism. Altogether, the association between sexual shape dimorphism and attractiveness is moderate for women and weak (or absent) for men. Analysis that distinguishes between allometric and non-allometric components reveals that non-allometric facial dimorphism is preferred in women's faces but not in faces of men. This might be due to different regimes of ongoing sexual selection acting on men, such as stronger intersexual selection for body height and more intense intrasexual physical competition, compared with women.
Collapse
|
14
|
Voegeli R, Schoop R, Prestat-Marquis E, Rawlings AV, Shackelford TK, Fink B. Cross-cultural perception of female facial appearance: A multi-ethnic and multi-centre study. PLoS One 2021; 16:e0245998. [PMID: 33481957 PMCID: PMC7822532 DOI: 10.1371/journal.pone.0245998] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/12/2021] [Indexed: 11/19/2022] Open
Abstract
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.
Collapse
Affiliation(s)
| | | | | | | | - Todd K. Shackelford
- Department of Psychology, Oakland University, Rochester, Michigan, United States of America
| | - Bernhard Fink
- Biosocial Science Information, Biedermannsdorf, Austria
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| |
Collapse
|
15
|
Pavlovič O, Fiala V, Kleisner K. Environmental convergence in facial preferences: a cross-group comparison of Asian Vietnamese, Czech Vietnamese, and Czechs. Sci Rep 2021; 11:550. [PMID: 33436663 PMCID: PMC7804147 DOI: 10.1038/s41598-020-79623-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 12/09/2020] [Indexed: 11/08/2022] Open
Abstract
It has been demonstrated that sociocultural environment has a significant impact on human behavior. This contribution focuses on differences in the perception of attractiveness of European (Czech) faces as rated by Czechs of European origin, Vietnamese persons living in the Czech Republic and Vietnamese who permanently reside in Vietnam. We investigated whether attractiveness judgments and preferences for facial sex-typicality and averageness in Vietnamese who grew up and live in the Czech Republic are closer to the judgements and preferences of Czech Europeans or to those of Vietnamese born and residing in Vietnam. We examined the relative contribution of sexual shape dimorphism and averageness to the perception of facial attractiveness across all three groups of raters. Czech Europeans, Czech Vietnamese, and Asian Vietnamese raters of both sexes rated facial portraits of 100 Czech European participants (50 women and 50 men, standardized, non-manipulated) for attractiveness. Taking Czech European ratings as a standard for Czech facial attractiveness, we showed that Czech Vietnamese assessments of attractiveness were closer to this standard than assessments by the Asian Vietnamese. Among all groups of raters, facial averageness positively correlated with perceived attractiveness, which is consistent with the "average is attractive" hypothesis. A marginal impact of sexual shape dimorphism on attractiveness rating was found only in Czech European male raters: neither Czech Vietnamese nor Asian Vietnamese raters of either sex utilized traits associated with sexual shape dimorphism as a cue of attractiveness. We thus conclude that Vietnamese people permanently living in the Czech Republic converge with Czechs of Czech origin in perceptions of facial attractiveness and that this population adopted some but not all Czech standards of beauty.
Collapse
Affiliation(s)
- Ondřej Pavlovič
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Vinicna 7, Prague, 128 44, Czech Republic
| | - Vojtěch Fiala
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Vinicna 7, Prague, 128 44, Czech Republic
| | - Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Vinicna 7, Prague, 128 44, Czech Republic.
| |
Collapse
|
16
|
Catz O, Lewis MB. Exploring distinctiveness, attractiveness and sexual dimorphism in actualized face-spaces. VISUAL COGNITION 2020. [DOI: 10.1080/13506285.2020.1797967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Or Catz
- Psychology Department, Ashkelon Academic College, Ashkelon, Israel
| | | |
Collapse
|
17
|
Kočnar T, Saribay SA, Kleisner K. Perceived attractiveness of Czech faces across 10 cultures: Associations with sexual shape dimorphism, averageness, fluctuating asymmetry, and eye color. PLoS One 2019; 14:e0225549. [PMID: 31751432 PMCID: PMC6872208 DOI: 10.1371/journal.pone.0225549] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/06/2019] [Indexed: 01/17/2023] Open
Abstract
Research on the perception of faces typically assumes that there are some universal values of attractiveness which are shared across individuals and cultures. The perception of attractiveness may, however, vary across cultures due to local differences in both facial morphology and standards of beauty. To examine cross-cultural consensus in the ratings of attractiveness, we presented a set of 120 non-manipulated photographs of Czech faces to ten samples of raters from both European (Czech Republic, Estonia, Sweden, Romania, Turkey, Portugal) and non-European countries (Brazil, India, Cameroon, Namibia). We examined the relative contribution of three facial markers (sexual shape dimorphism, averageness, fluctuating asymmetry) to the perception of attractiveness as well as the possible influence of eye color, which is a locally specific trait. In general, we found that both male and female faces which were closer to the average and more feminine in shape were regarded as more attractive, while fluctuating asymmetry had no effect. Despite a high cross-cultural consensus on attractiveness standards, significant differences in the perception of attractiveness seem to be related to the level of socio-economic development (as measured by the Human Development Index, HDI). Attractiveness ratings by raters from low-HDI countries (India, Cameroon, Namibia) converged less with ratings from Czech Republic than ratings from high-HDI countries (European countries and Brazil). With respect to eye color, some local patterns emerged which we discuss as a consequence of negative frequency-dependent selection.
Collapse
Affiliation(s)
- Tomáš Kočnar
- Department of Philosophy and History of Science, Charles University in Prague, Prague, Czech Republic
| | - S. Adil Saribay
- Department of Psychology, Boğaziçi University, Istanbul, Turkey
| | - Karel Kleisner
- Department of Philosophy and History of Science, Charles University in Prague, Prague, Czech Republic
| |
Collapse
|
18
|
Biological Bases of Beauty Revisited: The Effect of Symmetry, Averageness, and Sexual Dimorphism on Female Facial Attractiveness. Symmetry (Basel) 2019. [DOI: 10.3390/sym11020279] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The factors influencing human female facial attractiveness—symmetry, averageness, and sexual dimorphism—have been extensively studied. However, recent studies, using improved methodologies, have called into question their evolutionary utility and links with life history. The current studies use a range of approaches to quantify how important these factors actually are in perceiving attractiveness, through the use of novel statistical analyses and by addressing methodological weaknesses in the literature. Study One examines how manipulations of symmetry, averageness, femininity, and masculinity affect attractiveness using a two-alternative forced choice task, finding that increased masculinity and also femininity decrease attractiveness, compared to unmanipulated faces. Symmetry and averageness yielded a small and large effect, respectively. Study Two utilises a naturalistic ratings paradigm, finding similar effects of averageness and masculinity as Study One but no effects of symmetry and femininity on attractiveness. Study Three applies geometric face measurements of the factors and a random forest machine learning algorithm to predict perceived attractiveness, finding that shape averageness, dimorphism, and skin texture symmetry are useful features capable of relatively accurate predictions, while shape symmetry is uninformative. However, the factors do not explain as much variance in attractiveness as the literature suggests. The implications for future research on attractiveness are discussed.
Collapse
|
19
|
Schmälzle R, Hartung FM, Barth A, Imhof MA, Kenter A, Renner B, Schupp HT. Visual cues that predict intuitive risk perception in the case of HIV. PLoS One 2019; 14:e0211770. [PMID: 30785898 PMCID: PMC6382111 DOI: 10.1371/journal.pone.0211770] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 01/22/2019] [Indexed: 11/26/2022] Open
Abstract
Field studies indicate that people may form impressions about potential partners’ HIV risk, yet lack insight into what underlies such intuitions. The present study examined which cues may give rise to the perception of riskiness. Towards this end, portrait pictures of persons that are representative of the kinds of images found on social media were evaluated by independent raters on two sets of data: First, sixty visible cues deemed relevant to person perception, and second, perceived HIV risk and trustworthiness, health, and attractiveness. Here, we report correlations between cues and perceived HIV risk, exposing cue-criterion associations that may be used to infer intuitively HIV risk. Second, we trained a multiple cue-based model to forecast perceived HIV risk through cross-validated predictive modelling. Trained models accurately predicted how ‘risky’ a person was perceived (r = 0.75) in a novel sample of portraits. Findings are discussed with respect to HIV risk stereotypes and implications regarding how to foster effective protective behaviors.
Collapse
Affiliation(s)
- Ralf Schmälzle
- Department of Communication, Michigan State University, East Lansing, Michigan, United States of America
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
- * E-mail:
| | - Freda-Marie Hartung
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
- Department of Communication & Environment, Hochschule Rhein-Waal, Kamp-Lintfort, Nordrhein-Westfalen, Germany
| | - Alexander Barth
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Martin A. Imhof
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Alex Kenter
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Britta Renner
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Harald T. Schupp
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| |
Collapse
|
20
|
Kleisner K, Pokorný Š, Saribay SA. Toward a New Approach to Cross-Cultural Distinctiveness and Typicality of Human Faces: The Cross-Group Typicality/ Distinctiveness Metric. Front Psychol 2019; 10:124. [PMID: 30766504 PMCID: PMC6365443 DOI: 10.3389/fpsyg.2019.00124] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/14/2019] [Indexed: 11/20/2022] Open
Abstract
In the present research, we took advantage of geometric morphometrics to propose a data-driven method for estimating the individual degree of facial typicality/distinctiveness for cross-cultural (and other cross-group) comparisons. Looking like a stranger in one’s home culture may be somewhat stressful. The same facial appearance, however, might become advantageous within an outgroup population. To address this fit between facial appearance and cultural setting, we propose a simple measure of distinctiveness/typicality based on position of an individual along the axis connecting the facial averages of two populations under comparison. The more distant a face is from its ingroup population mean toward the outgroup mean the more distinct it is (vis-à-vis the ingroup) and the more it resembles the outgroup standards. We compared this new measure with an alternative measure based on distance from outgroup mean. The new measure showed stronger association with rated facial distinctiveness than distance from outgroup mean. Subsequently, we manipulated facial stimuli to reflect different levels of ingroup-outgroup distinctiveness and tested them in one of the target cultures. Perceivers were able to successfully distinguish outgroup from ingroup faces in a two-alternative forced-choice task. There was also some evidence that this task was harder when the two faces were closer along the axis connecting the facial averages from the two cultures. Future directions and potential applications of our proposed approach are discussed.
Collapse
Affiliation(s)
- Karel Kleisner
- Department of Philosophy and History of Science, Charles University, Prague, Czechia
| | - Šimon Pokorný
- Department of Philosophy and History of Science, Charles University, Prague, Czechia
| | - S Adil Saribay
- Department of Psychology, Boǧaziçi University, Istanbul, Turkey
| |
Collapse
|
21
|
Pecháček P, Stella D, Kleisner K. A morphometric analysis of environmental dependences between ultraviolet patches and wing venation patterns in Gonepteryx butterflies (Lepidoptera, Pieridae). Evol Ecol 2019. [DOI: 10.1007/s10682-019-09969-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
22
|
Robertson JM, Kingsley BE. Sexually Dimorphic Faciometrics in Black Racial Groups From Early Adulthood to Late Middle Age. EVOLUTIONARY PSYCHOLOGY 2018; 16:1474704918811056. [PMID: 30458649 PMCID: PMC10480802 DOI: 10.1177/1474704918811056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 10/03/2018] [Indexed: 01/15/2023] Open
Abstract
An increasing body of research focusing on gender-related traits has utilized faciometrics in order to consider sexual dimorphism: Aspects as diverse as social heuristics, facial attractiveness, sexual orientation, aggression, and trustworthiness have all been investigated. However, the majority of these studies have tended to focus on White or Caucasian student populations and have paid little regard to either older populations or racial background. The current study therefore investigated sexual dimorphism in 450 participants (225 women) from a Black population across four age groups (20s, 30s, 40s, and 50s). In line with much previous research using White or Caucasian faces, the expected sexual dimorphism was seen in the younger age-group in three of the four indices (cheekbone prominence, facial width to lower facial height, and lower face height to full face height). However, consistent with more recent literature, the facial width to height ratio (fWHR) was not found to be significantly different between men and women in this age-group. Contrary to previous research, when considering broader age groups, the three established measures of facial sexual dimorphism, when looked at independently, remained static over time, but this was not true for fWHR. It is concluded that facial structure does not follow the same aging trajectory in all populations and care should be taken in choice of facial metric, depending on the nature of the sample under investigation.
Collapse
|
23
|
|