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Roth TS, Samara I, Perea-Garcia JO, Kret ME. No immediate attentional bias towards or choice bias for male secondary sexual characteristics in Bornean orang-utans (Pongo pygmaeus). Sci Rep 2024; 14:12095. [PMID: 38802458 PMCID: PMC11130206 DOI: 10.1038/s41598-024-62187-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 05/14/2024] [Indexed: 05/29/2024] Open
Abstract
Primate faces provide information about a range of variant and invariant traits, including some that are relevant for mate choice. For example, faces of males may convey information about their health or genetic quality through symmetry or facial masculinity. Because perceiving and processing such information may have bearing on the reproductive success of an individual, cognitive systems are expected to be sensitive to facial cues of mate quality. However, few studies have investigated this topic in non-human primate species. Orang-utans are an interesting species to test mate-relevant cognitive biases, because they are characterised by male bimaturism: some adult males are fully developed and bear conspicuous flanges on the side of their face, while other males look relatively similar to females. Here, we describe two non-invasive computerised experiments with Bornean orang-utans (Pongo pygmaeus), testing (i) immediate attention towards large flanges and symmetrical faces using a dot-probe task (N = 3 individuals; 2F) and (ii) choice bias for pictures of flanged males over unflanged males using a preference test (N = 6 individuals; 4F). In contrast with our expectations, we found no immediate attentional bias towards either large flanges or symmetrical faces. In addition, individuals did not show a choice bias for stimuli of flanged males. We did find exploratory evidence for a colour bias and energy efficiency trade-offs in the preference task. We discuss our null results and exploratory results in the context of the evolutionary history of Bornean orang-utans, and provide suggestions for a more biocentric approach to the study of orang-utan cognition.
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Affiliation(s)
- Tom S Roth
- Cognitive Psychology Unit, Institute of Psychology, The Faculty of Social and Behavioral Sciences, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands.
- Apenheul Primate Park, J.CWilslaan 21, 7313 HK, Apeldoorn, The Netherlands.
- Animal Behaviour & Cognition, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
| | - Iliana Samara
- Cognitive Psychology Unit, Institute of Psychology, The Faculty of Social and Behavioral Sciences, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands
- Leiden Institute of Brain and Cognition (LIBC), Leiden, The Netherlands
| | - Juan Olvido Perea-Garcia
- Cognitive Psychology Unit, Institute of Psychology, The Faculty of Social and Behavioral Sciences, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands
| | - Mariska E Kret
- Cognitive Psychology Unit, Institute of Psychology, The Faculty of Social and Behavioral Sciences, Leiden University, Wassenaarseweg 52, 2333 AK, Leiden, The Netherlands
- Leiden Institute of Brain and Cognition (LIBC), Leiden, The Netherlands
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Harvey AJ, White C, Madelin K, Morrison E. Impaired face symmetry detection under alcohol, but no 'beer goggles' effect. J Psychopharmacol 2024; 38:268-279. [PMID: 38069489 PMCID: PMC10944579 DOI: 10.1177/02698811231215592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
BACKGROUND The 'beer goggles' phenomenon describes sexual attraction to individuals when alcohol intoxicated whom we would not desire when sober. One possible explanation of the effect is that alcohol impairs the detection of facial asymmetry, thus lowering the drinker's threshold for physical attraction. AIMS We therefore tested the hypotheses that higher breath alcohol drinkers would award more generous ratings of attractiveness to asymmetrical faces, and be poorer at discriminating bilateral facial asymmetry than less intoxicated counterparts. METHODS Ninety-nine male and female bar patrons rated 18 individual faces for attractiveness and symmetry. Each type of rating was given twice, once per face with an enhanced asymmetry and once again for each face in its natural form. Participants then judged which of two same-face versions (one normal, the other perfectly symmetrised) was more attractive and, in the final task, more symmetrical. RESULTS Alcohol had no influence on attractiveness judgements but higher blood alcohol concentrations were associated with higher symmetry ratings. Furthermore, as predicted, heavily intoxicated individuals were less able to distinguish natural from perfectly symmetrised face versions than more sober drinkers. CONCLUSIONS Findings therefore suggest alcohol impairs face asymmetry detection, but it seems that this perceptual distortion does not contribute to the 'beer goggles' phenomenon.
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Affiliation(s)
| | - Ciara White
- Department of Psychology, University of Portsmouth, UK
| | | | - Ed Morrison
- Department of Psychology, University of Portsmouth, UK
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Arnocky S, Denomme B, Hodges-Simeon C, Hlay JK, Davis AC, Brennan H. Self-perceived Mate Value is Predicted by Biological and self-reported Indices of Health in Young Adults. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2023; 9:54-71. [PMID: 36686590 PMCID: PMC9838438 DOI: 10.1007/s40750-022-00209-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 01/12/2023]
Abstract
Immunocompetence can influence an organism's reproductive fitness, and thus presumably their desirability as a mate (i.e., mate value). In humans, the link between immunocompetence and mate value has found circumstantial support by way of both expressed mate preferences for healthy partners, and via preferences for attractive phenotypes that are ostensibly linked to immune functioning. We examined whether a biological marker of immunocompetence, salivary immunoglobulin A (sIgA), along with self-reported frequency and severity of symptoms of poor health predicted individuals' reported mate value and mating behavior in a sample of 691 young adults. Our measures of immunocompetence (sIgA and symptoms of poor health) correlated significantly with one another, suggesting sIgA is a viable marker of general immune function in young adults. We then examined the independent contributions of these variables to mate value, controlling for age, sex, and body mass index (BMI). Results showed that sIgA (positively) and poor health (negatively) predicted mate value, but not lifetime number of sex partners or current romantic relationship status. These findings suggest that those with better health and immune function report being more desirable as mating partners but support past research showing null links to reported mating behavior. Together, these findings suggest that more comprehensive work on links between immunocompetence and mating is required.
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Affiliation(s)
- Steven Arnocky
- Nipissing University, 100 College Drive, P1B8L7 North Bay, ON Canada
| | - Brittany Denomme
- Nipissing University, 100 College Drive, P1B8L7 North Bay, ON Canada
| | | | | | - Adam C. Davis
- Nipissing University, 100 College Drive, P1B8L7, North Bay, ON Canada
| | - Hillary Brennan
- Nipissing University, 100 College Drive, P1B8L7 North Bay, ON Canada
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Ertuğrul B, Aydık MF. No association between developmental instability as a general measure of stress and 2D:4D digit ratios in a non-western sample. Am J Hum Biol 2023; 35:e23860. [PMID: 36602102 DOI: 10.1002/ajhb.23860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE Random deviation from perfect symmetry of organisms is defined as fluctuating asymmetry. Fluctuating asymmetry is widely considered to be a marker of developmental instability, developmental noise and phenotypic quality at the population level. In this study, we investigated hypothesized relationship between 2D:4D digit ratios as a proxy measure of prenatal sex hormones and developmental instability levels in young adult humans. MATERIALS AND METHODS In the study, seven bilateral traits were measured for fluctuating asymmetry, as well as second and fourth digit lengths on both hands of 185 individuals, 87 men (mean age: 22.42 ± 3.37) and 97 women (mean age: 22.88 ± 3.87). The second digit length was divided by the fourth digit length and the resulting value was used as the digit ratio (2D:4D). Composite fluctuating asymmetry was calculated using five bilateral traits displaying fluctuating asymmetry. RESULTS Only the right hand 2D:4D ratio is lower in men than in women. However, this difference disappears when the effect of digit lengths is controlled. Composite fluctuating asymmetry results reveal that men are more asymmetrical than women. There was no significant relationship between digit ratios and composite fluctuating asymmetry. CONCLUSION In this study, the 2D:4D digit ratios appear to be influenced (at least in humans) by different digit lengths. This study also confirms previous studies that digit ratios as a proxy measure of exposure to either high testosterone or estrogen levels during early development does not appear to affect levels of developmental instability.
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Affiliation(s)
- Berna Ertuğrul
- Faculty of Literature, Department of Anthropology, İstanbul University, İstanbul, Turkey
| | - Muhammet Fatih Aydık
- Faculty of Literature, Department of Anthropology, İstanbul University, İstanbul, Turkey
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Developmental instability, fluctuating asymmetry, and human psychological science. Emerg Top Life Sci 2022; 6:311-322. [PMID: 35994000 DOI: 10.1042/etls20220025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/22/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022]
Abstract
Developmental instability (DI) is an individual's inability to produce a specific developmental outcome under a given set of conditions, generally thought to result from random perturbations experienced during development. Fluctuating asymmetry (FA) - asymmetry on bilateral features that, on average, are symmetrical (or asymmetry deviating from that arising from design) - has been used to measure DI. Dating to half a century ago, and accelerating in the past three decades, psychological researchers have examined associations between FA (typically measured on bodily or facial features) and a host of outcomes of interest, including psychological disorders, cognitive ability, attractiveness, and sexual behavior. A decade ago, a meta-analysis on findings from nearly 100 studies extracted several conclusions. On average, small but statistically reliable associations between FA and traits of interest exist. Though modest, these associations are expected to greatly underestimate the strength of associations with underlying DI. Despite the massive sample size across studies, we still lack a good handle on which traits are most strongly affected by DI. A major methodological implication of the meta-analysis is that most studies have been, individually, woefully underpowered to detect associations. Though offering some intriguing findings, much research is the past decade too has been underpowered; hence, the newer literature is also likely noisy. Several large-scale studies are exceptions. Future progress depends on additional large-scale studies and researchers' sensitivity to power issues. As well, theoretical assumptions and conceptualizations of DI and FA driving psychological research may need revision to explain empirical patterns.
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Shape asymmetry - what's new? Emerg Top Life Sci 2022; 6:285-294. [PMID: 35758318 DOI: 10.1042/etls20210273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 11/17/2022]
Abstract
Studies of shape asymmetry have become increasingly abundant as the methods of geometric morphometrics have gained widespread use. Most of these studies have focussed on fluctuating asymmetry and have largely obtained similar results as more traditional analyses of asymmetry in distance measurements, but several notable differences have also emerged. A key difference is that shape analyses provide information on the patterns, not just the amount of variation, and therefore tend to be more sensitive. Such analyses have shown that apparently symmetric structures in animals consistently show directional asymmetry for shape, but not for size. Furthermore, the long-standing prediction that phenotypic plasticity in response to environmental heterogeneity can contribute to fluctuating asymmetry has been confirmed for the first time for the shape of flower parts (but not for size). Finally, shape analyses in structures with complex symmetry, such as many flowers, can distinguish multiple types of directional asymmetry, generated by distinct direction-giving factors, which combine to the single component observable in bilaterally symmetric structures. While analyses of shape asymmetry are broadly compatible with traditional analyses of asymmetry, they incorporate more detailed morphological information, particularly for structures with complex symmetry, and therefore can reveal subtle biological effects that would otherwise not be apparent. This makes them a promising tool for a wide range of studies in the basic and applied life sciences.
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Borráz-León JI, Rantala MJ, Krams IA, Cerda-Molina AL, Contreras-Garduño J. Are Toxoplasma-infected subjects more attractive, symmetrical, or healthier than non-infected ones? Evidence from subjective and objective measurements. PeerJ 2022; 10:e13122. [PMID: 35356475 PMCID: PMC8958965 DOI: 10.7717/peerj.13122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 02/24/2022] [Indexed: 01/12/2023] Open
Abstract
Background Parasites are among the main factors that negatively impact the health and reproductive success of organisms. However, if parasites diminish a host's health and attractiveness to such an extent that finding a mate becomes almost impossible, the parasite would decrease its odds of reproducing and passing to the next generation. There is evidence that Toxoplasma gondii (T. gondii) manipulates phenotypic characteristics of its intermediate hosts to increase its spread. However, whether T. gondii manipulates phenotypic characteristics in humans remains poorly studied. Therefore, the present research had two main aims: (1) To compare traits associated with health and parasite resistance in Toxoplasma-infected and non-infected subjects. (2) To investigate whether other people perceive differences in attractiveness and health between Toxoplasma-infected and non-infected subjects of both sexes. Methods For the first aim, Toxoplasma-infected (n = 35) and non-infected subjects (n = 178) were compared for self-perceived attractiveness, number of sexual partners, number of minor ailments, body mass index, mate value, handgrip strength, facial fluctuating asymmetry, and facial width-to-height ratio. For the second aim, an independent group of 205 raters (59 men and 146 women) evaluated the attractiveness and perceived health of facial pictures of Toxoplasma-infected and non-infected subjects. Results First, we found that infected men had lower facial fluctuating asymmetry whereas infected women had lower body mass, lower body mass index, a tendency for lower facial fluctuating asymmetry, higher self-perceived attractiveness, and a higher number of sexual partners than non-infected ones. Then, we found that infected men and women were rated as more attractive and healthier than non-infected ones. Conclusions Our results suggest that some sexually transmitted parasites, such as T. gondii, may produce changes in the appearance and behavior of the human host, either as a by-product of the infection or as the result of the manipulation of the parasite to increase its spread to new hosts. Taken together, these results lay the foundation for future research on the manipulation of the human host by sexually transmitted pathogens and parasites.
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Affiliation(s)
| | | | - Indrikis A. Krams
- Department of Biotechnology, Daugavpils University, Daugavpils, Latvia,Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia,Department of Zoology and Animal Ecology, University of Latvia, Riga, Latvia
| | - Ana Lilia Cerda-Molina
- Department of Ethology, National Institute of Psychiatry “Ramón de la Fuente Muñiz”, Mexico City, Mexico
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Fajardo G, Polo P, Muñoz-Reyes JA, Rodríguez-Sickert C. Long-Term Mating Orientation in Men: The Role of Socioeconomic Status, Protection Skills, and Parenthood Disposition. Front Psychol 2022; 13:815819. [PMID: 35282237 PMCID: PMC8913582 DOI: 10.3389/fpsyg.2022.815819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/07/2022] [Indexed: 12/23/2022] Open
Abstract
From an evolutionary perspective, phenotypic, social, and environmental factors help to shape the different costs and benefits of pursuing different reproductive strategies (or a mixture of them) from one individual to another. Since men's reproductive success is mainly constrained to women's availability, their mating orientations should be partially calibrated by features that women prefer in a potential partner. For long-term relationships, women prefer traits that signal access to resources, protection skills, and the willingness to share them. Using generalized linear models with laboratory data taken from a Chilean population (N = 197), this study aimed to test whether real and potential resources (measured as self-reported socioeconomic status), protection skills (measured as handgrip strength), and the willingness to provide resources and protection (measured as their disposition toward parenthood) are related to mating orientation in men. Our predictions were: (1) socioeconomic status would be positively associated with long-term and short-term mating orientation but for long-term-oriented individuals, this would be enhanced by having a more favorable parenthood disposition and (2) strength would be positively related to long-term mating orientation in men with higher socioeconomic status and a favorable disposition toward parenthood and it would have a positive and direct association with short-term mating orientation. Our results partially supported the first hypothesis, since men with higher socioeconomic status were more long-term oriented, but parenting disposition did not moderate this effect. Contrary to our expectations, socioeconomic status was not related to short-term mating orientation. Strength appeared not to be significant for long-term mating orientation, even interacting with other traits. However, strength by itself was powerfully linked with a short-term mating orientation. Our results suggest that only some individuals that are attractive for long-term relationships are indeed long-term oriented and may reflect the overall conflict of interests between mating strategies among sexes.
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Affiliation(s)
- Gabriela Fajardo
- Laboratorio de Comportamiento Animal y Humano, Facultad de Gobierno, Centro de Investigación en Complejidad Social, Universidad del Desarrollo, Santiago, Chile
| | - Pablo Polo
- Laboratorio de Comportamiento Animal y Humano, Facultad de Gobierno, Centro de Investigación en Complejidad Social, Universidad del Desarrollo, Santiago, Chile
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Viña del Mar, Chile
| | - José Antonio Muñoz-Reyes
- Laboratorio de Comportamiento Animal y Humano, Facultad de Gobierno, Centro de Investigación en Complejidad Social, Universidad del Desarrollo, Santiago, Chile
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Viña del Mar, Chile
| | - Carlos Rodríguez-Sickert
- Laboratorio de Comportamiento Animal y Humano, Facultad de Gobierno, Centro de Investigación en Complejidad Social, Universidad del Desarrollo, Santiago, Chile
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Abstract
Humans, like other species, have a preference for symmetrical visual stimuli, a preference that is influenced by factors such as age, sex, and artistic training. In particular, artistic training seems to decrease the rejection of asymmetry in abstract stimuli. However, it is not known whether the same trend would be observed in relation to concrete stimuli such as human faces. In this article, we investigated the role of expertise in visual arts, music, and dance, in the perceived beauty and attractiveness of human faces with different asymmetries. With this objective, the beauty and attractiveness of 100 photographs of faces with different degrees of asymmetry were evaluated by 116 participants with different levels of art expertise. Expertise in visual arts and dance was associated with the extent to which facial asymmetry influenced the beauty ratings assigned to the faces. The greater the art expertise in visual arts and dance, the more indifferent to facial asymmetry the participant was to evaluate beauty. The same effect was not found for music and neither for attractiveness ratings. These findings are important to help understand how face aesthetic evaluation is modified by artistic training and the difference between beauty and attractiveness evaluations.
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Like Father, Like Child? Paternal Age at Birth and Offspring’s Facial Asymmetry and Distinctiveness. Symmetry (Basel) 2022. [DOI: 10.3390/sym14020344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Paternal age at birth, a potential proxy of mutation load transmitted to the offspring, has previously been related to the offspring’s health, biological condition and reproductive potential. As higher facial asymmetry and distinctiveness serve as putative markers of the lower genetic quality of an individual, we hypothesize that more advanced paternal age at birth will be related to children’s higher levels of facial asymmetry and distinctiveness. To the best of our knowledge, this is the first study evaluating the link between paternal age at birth and facial asymmetry in offspring. Based on archived photographs of 159 children born within 47 Polish families, we have conducted facial geometric morphometric measurements and calculated the levels of facial asymmetry and distinctiveness. The relationship between paternal age at birth and the offspring’s facial features was explored with the use of Bayesian Linear Mixed-effects Models, controlling for sex, age and birth order of the offspring, and maternal age at child’s birth. No associations between paternal age at birth and facial asymmetry or distinctiveness in children were found. The lack of such a relationship might be a result of the potentially insufficient influence of newly accumulated paternal mutations affecting the offspring’s phenotype or higher importance of maternal (prenatal) and postnatal environments in shaping facial features.
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Changes in Facial Shape throughout Pregnancy—A Computational Exploratory Approach. Symmetry (Basel) 2021. [DOI: 10.3390/sym13101944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Facial cognition serves an important role in human daily interactions. It has been suggested that facial shape can serve as a signal for underlining biological condition, and that it is correlated with, among others, health, fertility, and attractiveness. In this study, 14 women were photographed during three consecutive trimesters of pregnancy, and the levels of their facial sexual dimorphism, asymmetry, and averageness were computed. Facial sexual dimorphism in first trimester was higher than in the second trimester (F(2, 22) = 5.77; p = 0.01; ηp2 = 0.34, post-hoc Tukey HSD test p = 0.007). Similar pattern was visible for asymmetry (F(2, 22) = 3.67; p = 0.04; ηp2 = 0.25, post-hoc Tukey HSD test p = 0.05). No statistically significant changes in measurement of averageness were observed. Results from Bayesian complementary analyses confirmed the observed effects for sexual dimorphism. The evidence for trimester differences in asymmetry and averageness was inconsequential. Based on the preliminary results of this exploratory study, we suggest that previously found decrease in observed facial attractiveness during pregnancy can be related to the decrease in computed facial femininity (possibly mediated by the changes in facial adiposity).
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Brown M, Tracy RE, Young SG, Sacco DF. Crowd Salience Heightens Tolerance to Healthy Facial Features. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2021; 7:432-446. [PMID: 34567952 PMCID: PMC8455113 DOI: 10.1007/s40750-021-00176-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Recent findings suggest crowd salience heightens pathogen-avoidant motives, serving to reduce individuals' infection risk through interpersonal contact. Such experiences may similarly facilitate the identification, and avoidance, of diseased conspecifics. The current experiment sought to replicate and extend previous crowding research. METHODS In this experiment, we primed participants at two universities with either a crowding or control experience before having them evaluate faces manipulated to appear healthy or diseased by indicating the degree to which they would want to interact with them. RESULTS Crowding-primed participants reported a more heightened preferences for healthy faces than control-primed participants. Additionally, crowd salience reduced aversion toward healthy faces but did not heighten aversion to diseased faces. CONCLUSION Results suggest crowding appears to heighten tolerance for health cues given the heightened proximal threat of infections through interpersonal contact within crowded environments. Conversely, this work extends previous findings by indicating this preference is not rooted in an aversion to cues of poor health. We frame findings from a threat management perspective in understanding how crowding fosters sensitivity toward pathogenic threats.
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Affiliation(s)
- Mitch Brown
- Department of Psychological Science, University of Arkansas, Fayetteville, AR 72701 USA
| | | | - Steven G. Young
- Graduate Center at CUNY, New York, NY USA
- CUNY Baruch College, New York, NY USA
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13
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Assessment of the Orbital and Auricular Asymmetry in Italian and Sudanese Children: A Three-Dimensional Study. Symmetry (Basel) 2021. [DOI: 10.3390/sym13091657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The evaluation of the symmetry of orbital and ear soft tissues is important for aesthetic and reconstructive surgery. However, little information is available for these facial regions, especially in children. We analyzed the orbital and auricular symmetry in 418 Italian and 206 Sudanese subadult males divided into three age groups (8–11, 12–15, and 16–19 years old). Orbital and auricular height and width were measured for calculating fluctuating and directional asymmetry indices. Differences in asymmetry indices according to ethnicity and age group were assessed through the two-way ANOVA test (p < 0.01), while differences in the prevalence of right or left asymmetry according to ethnicity were assessed through the chi-square test. On average, directional asymmetry indices ranged from −2.1% to 1.1%, while fluctuating asymmetry indices ranged between 2.9% and 5.4%, corresponding to a small effect size and to 1.06–2.34 mm actual dimensions. Sudanese subjects showed a greater asymmetry for all the indices except for the fluctuating asymmetry of orbital height (p < 0.01). The directional asymmetry of auricular width increased with age. A prevalent right-side asymmetry was found for all the orbital indices (p < 0.001) in both populations, although significantly more prevalent in Sudanese individuals (over 83% for both measures), while auricular measures showed a prevalent left asymmetry exclusively in the Sudanese but with lower percentages. Aside from the limited effect size, the results proved the ethnic variability of asymmetry of orbital and auricle regions in children and suggest the need to collect more population data.
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Borráz-León JI, Rantala MJ, Luoto S, Krams IA, Contreras-Garduño J, Krama T, Cerda-Molina AL. Self-Perceived Facial Attractiveness, Fluctuating Asymmetry, and Minor Ailments Predict Mental Health Outcomes. ADAPTIVE HUMAN BEHAVIOR AND PHYSIOLOGY 2021. [DOI: 10.1007/s40750-021-00172-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abstract
Objective
Phenotypic markers associated with developmental stability such as fluctuating asymmetry, facial attractiveness, and reports of minor ailments can also act as indicators of overall physical health. However, few studies have assessed whether these markers might also be cues of mental health. We tested whether self- and other-perceived facial attractiveness, fluctuating asymmetry, and minor ailments are associated with psychopathological symptoms in a mixed sample of 358 college students, controlling for the effects of body mass index, age, and sex.
Methods
We applied the Symptom Checklist-90-Revised (SCL-90-R) questionnaire to assess psychopathological symptoms, a battery of questionnaires about self-perceptions of facial attractiveness, and gathered information about the number of previous minor ailments as well as demographic data. Other-perceived attractiveness was assessed by an independent mixed sample of 109 subjects. Subjects’ facial fluctuating asymmetry was determined by geometric morphometrics.
Results
The results revealed that in both men and women, higher self-perceived attractiveness and fewer minor ailments predicted lower scores of Somatization, Obsessive–Compulsive, Interpersonal Sensitivity, Depression, Anxiety, Phobic Anxiety, Paranoid Ideation, Psychoticism, and a General Psychopathology Index. Higher facial fluctuating asymmetry was associated with higher Interpersonal Sensitivity, but did not contribute to its prediction when controlling for the other studied variables.
Conclusions
The observed strong associations between self-perceived attractiveness, minor ailments, and psychopathology indicate common developmental pathways between physiological and psychological symptomatology which may reflect broader life history (co)variation between genetics, developmental environment, and psychophysiological functioning.
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Young SG, Brown M, Sacco DF. Using psychological science to support social distancing: Tradeoffs between affiliation and disease‐avoidance motivations. SOCIAL AND PERSONALITY PSYCHOLOGY COMPASS 2021. [DOI: 10.1111/spc3.12597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Steven G. Young
- Baruch College City University of New York New York City New York USA
- The Graduate Center City University of New York New York City New York USA
| | - Mitch Brown
- University of Arkansas Fayetteville Arkansas USA
| | - Donald F. Sacco
- The University of Southern Mississippi Hattiesburg Mississippi USA
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Farnell DJJ, Richmond S, Galloway J, Zhurov AI, Pirttiniemi P, Heikkinen T, Harila V, Matthews H, Claes P. An exploration of adolescent facial shape changes with age via multilevel partial least squares regression. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 200:105935. [PMID: 33485077 PMCID: PMC7920996 DOI: 10.1016/j.cmpb.2021.105935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/05/2021] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND OBJECTIVES Multilevel statistical models represent the existence of hierarchies or clustering within populations of subjects (or shapes in this work). This is a distinct advantage over single-level methods that do not. Multilevel partial-least squares regression (mPLSR) is used here to study facial shape changes with age during adolescence in Welsh and Finnish samples comprising males and females. METHODS 3D facial images were obtained for Welsh and Finnish male and female subjects at multiple ages from 12 to 17 years old. 1000 3D points were defined regularly for each shape by using "meshmonk" software. A three-level model was used here, including level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The mathematical formalism of mPLSR is given in an Appendix. RESULTS Differences in facial shape between the ages of 12 and 17 predicted by mPLSR agree well with previous results of multilevel principal components analysis (mPCA); buccal fat is reduced with increasing age and features such as the nose, brow, and chin become larger and more distinct. Differences due to ethnicity and sex are also observed. Plausible simulated faces are predicted from the model for different ages, sexes and ethnicities. Our models provide good representations of the shape data by consideration of appropriate measures of model fit (RMSE and R2). CONCLUSIONS Repeat measures in our dataset for the same subject at different ages can only be modelled indirectly at the lowest level of the model at discrete ages via mPCA. By contrast, mPLSR models age explicitly as a continuous covariate, which is a strong advantage of mPLSR over mPCA. These investigations demonstrate that multivariate multilevel methods such as mPLSR can be used to describe such age-related changes for dense 3D point data. mPLSR might be of much use in future for the prediction of facial shapes for missing persons at specific ages or for simulating shapes for syndromes that affect facial shape in new subject populations.
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Affiliation(s)
- D J J Farnell
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom.
| | - S Richmond
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom
| | - J Galloway
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom
| | - A I Zhurov
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom
| | - P Pirttiniemi
- Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland
| | - T Heikkinen
- Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland
| | - V Harila
- Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland
| | - H Matthews
- Medical Imaging Research Center, UZ Leuven, 3000 Leuven, Belgium; Department of Human Genetics, KU Leuven, 3000 Leuven, Belgium; Facial Sciences Research Group, Murdoch Children's Research Institute, Melbourne; Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - P Claes
- Medical Imaging Research Center, UZ Leuven, 3000 Leuven, Belgium; Department of Human Genetics, KU Leuven, 3000 Leuven, Belgium; Department of Electrical Engineering, ESAT/PSI, KU Leuven, 3000 Leuven, Belgium
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Osu T, Lechler-Lombardi J, Butler A, Newman M, Miłkowska K, Galbarczyk A, Richards G. Fluctuating asymmetry of finger lengths, digit ratio (2D:4D), and tattoos: A pre-registered replication and extension of Koziel et al. (2010). Early Hum Dev 2021; 152:105273. [PMID: 33227633 DOI: 10.1016/j.earlhumdev.2020.105273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Tattoos bring risks yet no obvious evolutionary benefit. Koziel et al. (2010) reported increased fluctuating symmetry (a proxy for low developmental instability) in tattooed men, suggesting they could serve as fitness indicators. AIMS We replicate and extend the findings of Koziel et al. by examining fluctuating asymmetry of finger lengths and digit ratio (2D:4D) (a putative indicator of prenatal testosterone exposure) as predictors of adult tattoo prevalence. STUDY DESIGN We used an online survey with a correlational design. SUBJECTS Participants were recruited from the UK and Poland via university participant pools and social media. Data were available for presence/absence of tattoos and at least one predictor variable (composite Fluctuating Asymmetry [cFA], right-hand digit ratio [R2D:4D] and left-hand digit ratio [L2D:4D]) for n = 186 males and n = 997 females. OUTCOME MEASURES We firstly assessed presence/absence of tattoos; when at least one tattoo was present, we also examined overall number and highest visibility. RESULTS Greater cFA was associated with lower likelihood of having tattoos in males, though in females greater cFA was associated with higher numbers of tattoos. R2D:4D and L2D:4D correlated negatively with number of tattoos in males, and a positive correlation between L2D:4D and number of tattoos was observed in females. However, these latter findings did not remain significant after controlling for covariates. CONCLUSIONS Tattoos may act as fitness indicators in males, though this explanation appears not to extend to females. Prenatal testosterone may also play a role, though doubt is cast on this premise because 2D:4D effects did not remain statistically significant after controlling for covariates.
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Affiliation(s)
- Tinisha Osu
- School of Psychology, Faculty of Medical Sciences, Newcastle University, UK
| | | | - Amy Butler
- School of Psychology, Faculty of Medical Sciences, Newcastle University, UK
| | - Miles Newman
- School of Psychology, Faculty of Medical Sciences, Newcastle University, UK
| | - Karolina Miłkowska
- Department of Environmental Health, Faculty of Health Science, Jagiellonian University Medical College, Poland
| | - Andrzej Galbarczyk
- Department of Environmental Health, Faculty of Health Science, Jagiellonian University Medical College, Poland
| | - Gareth Richards
- School of Psychology, Faculty of Medical Sciences, Newcastle University, UK.
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Weiss S, Grewe CM, Olderbak S, Goecke B, Kaltwasser L, Hildebrandt A. Symmetric or not? A holistic approach to the measurement of fluctuating asymmetry from facial photographs. PERSONALITY AND INDIVIDUAL DIFFERENCES 2020. [DOI: 10.1016/j.paid.2020.110137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Figueroa O, Muñoz-Reyes JA, Rodriguez-Sickert C, Valenzuela N, Pavez P, Ramírez-Herrera O, Pita M, Diaz D, Fernández-Martínez AB, Polo P. Testing strategic pluralism: The roles of attractiveness and competitive abilities to understand conditionality in men's short-term reproductive strategies. PLoS One 2020; 15:e0237315. [PMID: 32866153 PMCID: PMC7458284 DOI: 10.1371/journal.pone.0237315] [Citation(s) in RCA: 3] [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: 10/02/2019] [Accepted: 07/23/2020] [Indexed: 01/20/2023] Open
Abstract
The decision to allocate time and energy to find multiple sexual partners or raise children is a fundamental reproductive trade-off. The Strategic Pluralism Hypothesis argues that human reproductive strategies are facultatively calibrated towards either investing in mating or parenting (or a mixture), according to the expression of features dependent on the individual's condition. This study seeks to test predictions derived from this hypothesis in a sample of 242 young men (M ± SD = 22.12 ± 3.08) from Chile's 5th Region (33֯ south latitude). Specifically, two predictions were considered that raise questions about the relationship between traits related to physical and psychological attractiveness (fluctuating facial asymmetry and self-perception of attractiveness) and competitive skills (baseline testosterone and self-perception of fighting ability) with short-term reproductive strategies. Our results indicate that psychological features related to the self-perception of physical attractiveness are related to short-term reproductive strategies. However, no evidence was found that fluctuating facial asymmetry, basal levels of testosterone and self-perception of fighting ability were related to short-term reproductive strategies. These results support the existing evidence of the importance of physical attractiveness in calibrating men's reproductive strategies but cast doubts about the role of fluctuating facial asymmetry. They also suggest that traits related to physical attractiveness, in comparison to competitive capabilities, play a more important role in calibrating men's short-term reproductive strategies.
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Affiliation(s)
- Oriana Figueroa
- Doctorado en Ciencias de la Complejidad Social, Centro de Investigación en Complejidad Social, Facultad de Gobierno, Universidad del Desarrollo, Concepción, Chile
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Valparaíso, Chile
| | - Jose Antonio Muñoz-Reyes
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Valparaíso, Chile
| | - Carlos Rodriguez-Sickert
- Centro de Investigación en Complejidad Social, Facultad de Gobierno, Universidad del Desarrollo, Concepción, Chile
| | - Nohelia Valenzuela
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Valparaíso, Chile
- Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña del Mar, Chile
| | - Paula Pavez
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Valparaíso, Chile
| | - Oriana Ramírez-Herrera
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Valparaíso, Chile
| | - Miguel Pita
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, España
| | - David Diaz
- Facultad de Ciencias Económicas, Universidad de Chile, Santiago, Chile
| | | | - Pablo Polo
- Laboratorio de Comportamiento Animal y Humano, Centro de Estudios Avanzados, Universidad de Playa Ancha, Valparaíso, Chile
- * E-mail:
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20
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Farnell DJJ, Richmond S, Galloway J, Zhurov AI, Pirttiniemi P, Heikkinen T, Harila V, Matthews H, Claes P. Multilevel principal components analysis of three-dimensional facial growth in adolescents. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 188:105272. [PMID: 31865094 DOI: 10.1016/j.cmpb.2019.105272] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 11/19/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND OBJECTIVES The study of age-related facial shape changes across different populations and sexes requires new multivariate tools to disentangle different sources of variations present in 3D facial images. Here we wish to use a multivariate technique called multilevel principal components analysis (mPCA) to study three-dimensional facial growth in adolescents. METHODS These facial shapes were captured for Welsh and Finnish subjects (both male and female) at multiple ages from 12 to 17 years old (i.e., repeated-measures data). 1000 "dense" 3D points were defined regularly for each shape by using a deformable template via "meshmonk" software. A three-level model was used here, namely: level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The technicalities underpinning the mPCA method are presented in Appendices. RESULTS Eigenvalues via mPCA predicted that: level 1 (ethnicity/sex) contained 7.9% of variation; level 2 contained 71.5%; and level 3 (age) contained 20.6%. The results for the eigenvalues via mPCA followed a similar pattern to those results of single-level PCA. Results for modes of variation made sense, where effects due to ethnicity, sex, and age were reflected in modes at appropriate levels of the model. Standardised scores at level 1 via mPCA showed much stronger differentiation between sex and ethnicity groups than results of single-level PCA. Results for standardised scores from both single-level PCA and mPCA at level 3 indicated that females had different average "trajectories" with respect to these scores than males, which suggests that facial shape matures in different ways for males and females. No strong evidence of differences in growth patterns between Finnish and Welsh subjects was observed. CONCLUSIONS mPCA results agree with existing research relating to the general process of facial changes in adolescents with respect to age quoted in the literature. They support previous evidence that suggests that males demonstrate larger changes and for a longer period of time compared to females, especially in the lower third of the face. These calculations are therefore an excellent initial test that multivariate multilevel methods such as mPCA can be used to describe such age-related changes for "dense" 3D point data.
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Affiliation(s)
- D J J Farnell
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom.
| | - S Richmond
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom
| | - J Galloway
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom
| | - A I Zhurov
- School of Dentistry, Cardiff University, Heath Park, Cardiff CF14 4XY, United Kingdom
| | - P Pirttiniemi
- Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland
| | - T Heikkinen
- Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland
| | - V Harila
- Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland
| | - H Matthews
- Medical Imaging Research Center, UZ Leuven, 3000 Leuven, Belgium; Department of Human Genetics, KU Leuven, 3000 Leuven, Belgium; OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Leuven, Belgium; Facial Sciences Research Group, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - P Claes
- Medical Imaging Research Center, UZ Leuven, 3000 Leuven, Belgium; Department of Human Genetics, KU Leuven, 3000 Leuven, Belgium; Department of Electrical Engineering, ESAT/PSI, KU Leuven, 3000 Leuven, Belgium
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Marcinkowska UM, Holzleitner IJ. Stability of women's facial shape throughout the menstrual cycle. Proc Biol Sci 2020; 287:20192910. [PMID: 32259474 DOI: 10.1098/rspb.2019.2910] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Facial characteristics can serve as a cue for judgements of multiple human traits, from maternal tendencies, overall fertility to sexual openness. In this study, we tested previously found fluctuations in facial shape throughout the menstrual cycle. With methods more robust than those formerly used (larger sample size and detailed hormonal assessments determining the timing of the ovulation), we did not find significant changes in either of the three facial measurements conducted: symmetry, averageness and sexual dimorphism (all F ≤ 0.78, all partial η2 ≤ 0.01, all p ≥ 0.542). After narrowing the sample to cycles that had a higher probability of being ovulatory (based on daily measurements of luteinizing hormone and oestradiol), the results remained non-significant (all F ≤ 1.20, all partial η2 ≤ 0.03, all p ≥ 0.315). Our results (i) suggest that the previously found increased facial attractiveness of women in the most fertile phase of the menstrual cycle is not driven by changes in facial shape, but might instead stem from other changes in facial appearance, such as a more attractive skin tone; and (ii) underline the importance of replication of studies with new methods.
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Affiliation(s)
- U M Marcinkowska
- Department of Anthropology, Yale University, USA.,Faculty of Health Sciences, Jagiellonian University Medical College, Poland
| | - I J Holzleitner
- Institute of Neuroscience and Psychology, University of Glasgow, Scotland, UK
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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] [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.
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Thiesen G, Freitas MPM, Gribel BF, Kim KB. Comparison of maxillomandibular asymmetries in adult patients presenting different sagittal jaw relationships. Dental Press J Orthod 2019; 24:54-62. [PMID: 31508707 PMCID: PMC6733234 DOI: 10.1590/2177-6709.24.4.054-062.oar] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 10/22/2018] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The present study aims at using cone beam computed tomography (CBCT) to analyze the maxillomandibular characteristics present in adults with mandibular asymmetries and different sagittal jaw relationships. METHODS 360 patients were selected and divided into three groups (Class I, Class II, and Class III), with 120 individuals per group. The groups were then subdivided according to the intensity of lateral deviation of the gnathion point, into: 1) relative symmetry, 2) moderate asymmetry, and 3) severe asymmetry. Three planes of reference were established in the CBCT images and several measurements were taken to compare the bilateral skeletal differences between the intensities of asymmetry for the different sagittal jaw relationships. RESULTS When the groups were compared by the intensity of asymmetry, significant differences among patients with relative symmetry and moderate to severe asymmetry were found. This was especially noticed for severe asymmetry, suggesting that the deviation of the chin did not constitute the only morphological alteration for these patients, especially because a series of measurements showed significant bilateral differences. When comparing sagittal jaw relationships, the only significant finding was the vertical positioning of the gonion between Class II and III patients with severe asymmetry. CONCLUSIONS When comparing the three sagittal jaw relationships with the same intensity of asymmetry, most maxillofacial aspects were quite similar. The only difference was found for patients with severe asymmetry, as the individuals with Class II showed greater bilateral difference in the vertical positioning of the gonion, when compared to patients with Class III.
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Affiliation(s)
- Guilherme Thiesen
- Universidade do Sul de Santa Catarina, Departamento de Ortodontia (Florianópolis/SC, Brazil)
| | | | | | - Ki Beom Kim
- Saint Louis University, Department of Orthodontics (Saint Louis/MO, USA)
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24
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Wen YF, Wong HM, McGrath CP. Developmental shape changes in facial morphology: Geometric morphometric analyses based on a prospective, population-based, Chinese cohort in Hong Kong. PLoS One 2019; 14:e0218542. [PMID: 31252428 PMCID: PMC6599092 DOI: 10.1371/journal.pone.0218542] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/04/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Thorough understanding of developmental changes of human facial shape is lacking. The present study aimed to evaluate developmental shape changes of facial morphology based on a prospective, population-representative, Chinese cohort in Hong Kong. METHODS A population-representative sample of Chinese in Hong Kong was followed. Serial facial images of over 260 participants were obtained at age 12, 15, and 18 years. Facial landmarks were digitized and the corresponding coordinates were submitted for Generalized Procrustes Analysis. The resultant Procrustes shape coordinates, which captured shape information encoded by the facial landmarks, were then used for statistical shape analyses. RESULTS Small but significant developmental changes in mean facial shape were observed (p < 0.0001 for all pairwise comparisons). Significant age-related changes in the magnitude of variance of facial shape were also observed (p < 0.05). Phenotypic growth trajectories representing developmental shape changes were similar in size (p > 0.05) between sexes but differed in direction (p < 0.05) in shape space and trajectory shape (p < 0.05). The magnitude of shape differences between sexes remained constant from 12 to 18 years. Results of frontal facial shape analyses after removing the effect of allometry were similar to results obtained before removal of allometry. For lateral facial configurations, allometric trajectories among the age-by-sex groups were similar in slope (p > 0.05) but varied in directions in the multidimensional shape space. CONCLUSIONS Our findings suggested significant age-related changes in facial shape and provided a dynamic view of developmental changes in sexual dimorphism of facial shape. Allometry contributed minimally to developmental changes in frontal facial shape. In addition, the allometric trajectories for lateral facial configurations were similar in rate of shape change but differed in their directions in shape space.
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Affiliation(s)
- Yi Feng Wen
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi’an Jiaotong University, Xi’an, China
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi’an Jiaotong University, Xi’an, China
| | - Hai Ming Wong
- Paediatric Dentistry, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
- * E-mail:
| | - Colman P. McGrath
- Dental Public Health, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
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Bertamini M, Rampone G, Makin ADJ, Jessop A. Symmetry preference in shapes, faces, flowers and landscapes. PeerJ 2019; 7:e7078. [PMID: 31245176 PMCID: PMC6585942 DOI: 10.7717/peerj.7078] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 05/06/2019] [Indexed: 11/20/2022] Open
Abstract
Most people like symmetry, and symmetry has been extensively used in visual art and architecture. In this study, we compared preference for images of abstract and familiar objects in the original format or when containing perfect bilateral symmetry. We created pairs of images for different categories: male faces, female faces, polygons, smoothed version of the polygons, flowers, and landscapes. This design allows us to compare symmetry preference in different domains. Each observer saw all categories randomly interleaved but saw only one of the two images in a pair. After recording preference, we recorded a rating of how salient the symmetry was for each image, and measured how quickly observers could decide which of the two images in a pair was symmetrical. Results reveal a general preference for symmetry in the case of shapes and faces. For landscapes, natural (no perfect symmetry) images were preferred. Correlations with judgments of saliency were present but generally low, and for landscapes the salience of symmetry was negatively related to preference. However, even within the category where symmetry was not liked (landscapes), the separate analysis of original and modified stimuli showed an interesting pattern: Salience of symmetry was correlated positively (artificial) or negatively (original) with preference, suggesting different effects of symmetry within the same class of stimuli based on context and categorization.
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Affiliation(s)
- Marco Bertamini
- Department of Psychological Science, University of Liverpool, Liverpool, UK
| | - Giulia Rampone
- School of Psychology, University of Liverpool, Liverpool, UK
| | - Alexis D J Makin
- Department of Psychological Science, University of Liverpool, Liverpool, UK
| | - Andrew Jessop
- Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
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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.
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Ekrami O, Claes P, White JD, Zaidi AA, Shriver MD, Van Dongen S. Measuring asymmetry from high-density 3D surface scans: An application to human faces. PLoS One 2018; 13:e0207895. [PMID: 30586353 PMCID: PMC6306226 DOI: 10.1371/journal.pone.0207895] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 11/07/2018] [Indexed: 12/02/2022] Open
Abstract
Perfect bilateral symmetry is the optimal outcome of the development of bilateral traits in the absence of developmental perturbations. Any random perturbation in this perfect symmetrical state is called Fluctuating Asymmetry (FA). Many studies have been conducted on FA as an indicator of Developmental Instability (DI) and its possible link with stress and individual quality in general and with attractiveness, health and level of masculinity or femininity in humans. Most human studies of facial asymmetry use 2D pictures and a limited number of landmarks. We developed a protocol to utilize high-density 3D scans of human faces to measure the level of asymmetry. A completely symmetric spatially dense anthropometric mask with paired vertices is non-rigidly mapped on target faces using an Iterative Closest Point (ICP) registration algorithm. A set of 19 manually indicated landmarks were used to validate the mapping precision. The protocol's accuracy in FA calculation is assessed, and results show that a spatially dense approach is more accurate. In addition, it generates an integrated asymmetry estimate across the entire face. Finally, the automatic nature of the protocol provides a great advantage by omitting the tedious step of manual landmark indication on the biological structure of interest.
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Affiliation(s)
- Omid Ekrami
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Peter Claes
- Medical Imaging Research Center (MIRC), Department of Electrical Engineering–ESAT, Faculty of Engineering, KU Leuven, Leuven, Belgium
| | - Julie D. White
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Arslan A. Zaidi
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Mark D. Shriver
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Stefan Van Dongen
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
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Richmond S, Howe LJ, Lewis S, Stergiakouli E, Zhurov A. Facial Genetics: A Brief Overview. Front Genet 2018; 9:462. [PMID: 30386375 PMCID: PMC6198798 DOI: 10.3389/fgene.2018.00462] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/20/2018] [Indexed: 12/20/2022] Open
Abstract
Historically, craniofacial genetic research has understandably focused on identifying the causes of craniofacial anomalies and it has only been within the last 10 years, that there has been a drive to detail the biological basis of normal-range facial variation. This initiative has been facilitated by the availability of low-cost hi-resolution three-dimensional systems which have the ability to capture the facial details of thousands of individuals quickly and accurately. Simultaneous advances in genotyping technology have enabled the exploration of genetic influences on facial phenotypes, both in the present day and across human history. There are several important reasons for exploring the genetics of normal-range variation in facial morphology. - Disentangling the environmental factors and relative parental biological contributions to heritable traits can help to answer the age-old question "why we look the way that we do?" - Understanding the etiology of craniofacial anomalies; e.g., unaffected family members of individuals with non-syndromic cleft lip/palate (nsCL/P) have been shown to differ in terms of normal-range facial variation to the general population suggesting an etiological link between facial morphology and nsCL/P. - Many factors such as ancestry, sex, eye/hair color as well as distinctive facial features (such as, shape of the chin, cheeks, eyes, forehead, lips, and nose) can be identified or estimated using an individual's genetic data, with potential applications in healthcare and forensics. - Improved understanding of historical selection and adaptation relating to facial phenotypes, for example, skin pigmentation and geographical latitude. - Highlighting what is known about shared facial traits, medical conditions and genes.
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Affiliation(s)
- Stephen Richmond
- Applied Clinical Research and Public Health, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Laurence J. Howe
- MRC Integrative Epidemiology Unit, Population Health Sciences, University of Bristol, Bristol, United Kingdom
- Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Sarah Lewis
- MRC Integrative Epidemiology Unit, Population Health Sciences, University of Bristol, Bristol, United Kingdom
- School of Oral and Dental Sciences, University of Bristol, Bristol, United Kingdom
| | - Evie Stergiakouli
- MRC Integrative Epidemiology Unit, Population Health Sciences, University of Bristol, Bristol, United Kingdom
- School of Oral and Dental Sciences, University of Bristol, Bristol, United Kingdom
| | - Alexei Zhurov
- Applied Clinical Research and Public Health, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, United Kingdom
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Pawlowski B, Borkowska B, Nowak J, Augustyniak D, Drulis-Kawa Z. Human body symmetry and immune efficacy in healthy adults. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 167:207-216. [DOI: 10.1002/ajpa.23617] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Boguslaw Pawlowski
- Department of Human Biology; University of Wroclaw; Kuźnicza 35, Wrocław, 50-138 Poland
| | - Barbara Borkowska
- Department of Human Biology; University of Wroclaw; Kuźnicza 35, Wrocław, 50-138 Poland
| | - Judyta Nowak
- Department of Human Biology; University of Wroclaw; Kuźnicza 35, Wrocław, 50-138 Poland
| | - Daria Augustyniak
- Department of Pathogen Biology and Immunology; University of Wroclaw; Przybyszewskiego 63, Wrocław, 51-148 Poland
| | - Zuzanna Drulis-Kawa
- Department of Pathogen Biology and Immunology; University of Wroclaw; Przybyszewskiego 63, Wrocław, 51-148 Poland
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Kleisner K, Kočnar T, Tureček P, Stella D, Akoko RM, Třebický V, Havlíček J. African and European perception of African female attractiveness. EVOL HUM BEHAV 2017. [DOI: 10.1016/j.evolhumbehav.2017.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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31
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Stephen ID, Hiew V, Coetzee V, Tiddeman BP, Perrett DI. Facial Shape Analysis Identifies Valid Cues to Aspects of Physiological Health in Caucasian, Asian, and African Populations. Front Psychol 2017; 8:1883. [PMID: 29163270 PMCID: PMC5670498 DOI: 10.3389/fpsyg.2017.01883] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 10/11/2017] [Indexed: 01/21/2023] Open
Abstract
Facial cues contribute to attractiveness, including shape cues such as symmetry, averageness, and sexual dimorphism. These cues may represent cues to objective aspects of physiological health, thereby conferring an evolutionary advantage to individuals who find them attractive. The link between facial cues and aspects of physiological health is therefore central to evolutionary explanations of attractiveness. Previously, studies linking facial cues to aspects of physiological health have been infrequent, have had mixed results, and have tended to focus on individual facial cues in isolation. Geometric morphometric methodology (GMM) allows a bottom–up approach to identifying shape correlates of aspects of physiological health. Here, we apply GMM to facial shape data, producing models that successfully predict aspects of physiological health in 272 Asian, African, and Caucasian faces – percentage body fat (21.0% of variance explained), body mass index (BMI; 31.9%) and blood pressure (BP; 21.3%). Models successfully predict percentage body fat and blood pressure even when controlling for BMI, suggesting that they are not simply measuring body size. Predicted values of BMI and BP, but not percentage body fat, correlate with health ratings. When asked to manipulate the shape of faces along the physiological health variable axes (as determined by the models), participants reduced predicted BMI, body fat and (marginally) BP, suggesting that facial shape provides a valid cue to aspects of physiological health.
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Affiliation(s)
- Ian D Stephen
- Department of Psychology, Macquarie University, Sydney, NSW, Australia.,ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, NSW, Australia.,Perception in Action Research Centre, Macquarie University, Sydney, NSW, Australia
| | - Vivian Hiew
- School of Psychology, University of Nottingham Malaysia Campus, Semenyih, Malaysia
| | - Vinet Coetzee
- Department of Genetics, University of Pretoria, Pretoria, South Africa
| | - Bernard P Tiddeman
- Department of Computer Science, Aberystwyth University, Aberystwyth, United Kingdom
| | - David I Perrett
- School of Psychology and Neuroscience, University of St. Andrews, St. Andrews, United Kingdom
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Factors Affecting the Perception of 3D Facial Symmetry from 2D Projections. Symmetry (Basel) 2017. [DOI: 10.3390/sym9100243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Brown M, Sacco DF. Put a (Limbal) Ring on It: Women Perceive Men's Limbal Rings as a Health Cue in Short-Term Mating Domains. PERSONALITY AND SOCIAL PSYCHOLOGY BULLETIN 2017; 44:80-91. [PMID: 28978250 DOI: 10.1177/0146167217733072] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Limbal rings are dark annuli encircling the iris that fluctuate in visibility based on health and age. Research also indicates their presence augments facial attractiveness. Given individuals' prioritization of health cues in short-term mates, those with limbal rings may be implicated as ideal short-term mates. Three studies tested whether limbal rings serve as veridical health cues, specifically the extent to which this cue enhances a person's value as a short-term mating partner. In Study 1, targets with limbal rings were rated as healthier, an effect that was stronger for female participants and male targets. In Study 2, temporally activated short-term mating motives led women to report a heightened preference for targets with limbal rings. In Study 3, women rated targets with limbal rings as more desirable short-term mates. Results provide evidence for limbal rings as veridical cues to health, particularly in relevant mating domains.
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Affiliation(s)
- Mitch Brown
- 1 The University of Southern Mississippi, Hattiesburg, USA
| | - Donald F Sacco
- 1 The University of Southern Mississippi, Hattiesburg, USA
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Dixson BJW, Little AC, Dixson HGW, Brooks RC. Do prevailing environmental factors influence human preferences for facial morphology? Behav Ecol 2017. [DOI: 10.1093/beheco/arx067] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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35
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Hujoel PP, Masterson EE, Bollen AM. Lower face asymmetry as a marker for developmental instability. Am J Hum Biol 2017; 29. [DOI: 10.1002/ajhb.23005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 01/23/2017] [Accepted: 03/11/2017] [Indexed: 12/22/2022] Open
Affiliation(s)
- Philippe P. Hujoel
- Oral Health Sciences; School of Dentistry, University of Washington; Box 357475, Seattle WA 98115
| | - Erin E. Masterson
- Oral Health Sciences; School of Dentistry, University of Washington; Box 357475, Seattle WA 98115
| | - A-M Bollen
- Orthodontics; School of Dentistry, University of Washington, Health Sciences; Box 357446, Seattle WA 98115
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36
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Developmental Origins of Limb Developmental Instability in Human Fetuses: Many Abnormalities Make the Difference. Symmetry (Basel) 2017. [DOI: 10.3390/sym9040051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Foo YZ, Simmons LW, Rhodes G. Predictors of facial attractiveness and health in humans. Sci Rep 2017; 7:39731. [PMID: 28155897 PMCID: PMC5290736 DOI: 10.1038/srep39731] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 11/28/2016] [Indexed: 11/08/2022] Open
Abstract
Facial attractiveness has been suggested to provide signals of biological quality, particularly health, in humans. The attractive traits that have been implicated as signals of biological quality include sexual dimorphism, symmetry, averageness, adiposity, and carotenoid-based skin colour. In this study, we first provide a comprehensive examination of the traits that predict attractiveness. In men, attractiveness was predicted positively by masculinity, symmetry, averageness, and negatively by adiposity. In women, attractiveness was predicted positively by femininity and negatively by adiposity. Skin colour did not predict attractiveness in either sex, suggesting that, despite recent interest in the literature, colour may play limited role in determining attractiveness. Male perceived health was predicted positively by averageness, symmetry, and skin yellowness, and negatively by adiposity. Female perceived health was predicted by femininity. We then examined whether appearance predicted actual health using measures that have been theoretically linked to sexual selection, including immune function, oxidative stress, and semen quality. In women, there was little evidence that female appearance predicted health. In men, we found support for the phenotype-linked fertility hypothesis that male masculinity signalled semen quality. However, we also found a negative relationship between averageness and semen quality. Overall, these results indicate weak links between attractive facial traits and health.
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Affiliation(s)
- Yong Zhi Foo
- ARC Centre of Excellence in Cognition and its Disorders, School of Psychology, University of Western Australia, 35 Stirling Hwy, Crawley, 6009, WA, Australia
- Centre for Evolutionary Biology & School of Animal Biology, University of Western Australia, 35 Stirling Hwy, Crawley, 6009, WA, Australia
| | - Leigh W. Simmons
- ARC Centre of Excellence in Cognition and its Disorders, School of Psychology, University of Western Australia, 35 Stirling Hwy, Crawley, 6009, WA, Australia
- Centre for Evolutionary Biology & School of Animal Biology, University of Western Australia, 35 Stirling Hwy, Crawley, 6009, WA, Australia
| | - Gillian Rhodes
- ARC Centre of Excellence in Cognition and its Disorders, School of Psychology, University of Western Australia, 35 Stirling Hwy, Crawley, 6009, WA, Australia
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Quinto-Sánchez M, Cintas C, Silva de Cerqueira CC, Ramallo V, Acuña-Alonzo V, Adhikari K, Castillo L, Gomez-Valdés J, Everardo P, De Avila F, Hünemeier T, Jaramillo C, Arias W, Fuentes M, Gallo C, Poletti G, Schuler-Faccini L, Bortolini MC, Canizales-Quinteros S, Rothhammer F, Bedoya G, Rosique J, Ruiz-Linares A, González-José R. Socioeconomic Status Is Not Related with Facial Fluctuating Asymmetry: Evidence from Latin-American Populations. PLoS One 2017; 12:e0169287. [PMID: 28060876 PMCID: PMC5218465 DOI: 10.1371/journal.pone.0169287] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 12/14/2016] [Indexed: 11/18/2022] Open
Abstract
The expression of facial asymmetries has been recurrently related with poverty and/or disadvantaged socioeconomic status. Departing from the developmental instability theory, previous approaches attempted to test the statistical relationship between the stress experienced by individuals grown in poor conditions and an increase in facial and corporal asymmetry. Here we aim to further evaluate such hypothesis on a large sample of admixed Latin Americans individuals by exploring if low socioeconomic status individuals tend to exhibit greater facial fluctuating asymmetry values. To do so, we implement Procrustes analysis of variance and Hierarchical Linear Modelling (HLM) to estimate potential associations between facial fluctuating asymmetry values and socioeconomic status. We report significant relationships between facial fluctuating asymmetry values and age, sex, and genetic ancestry, while socioeconomic status failed to exhibit any strong statistical relationship with facial asymmetry. These results are persistent after the effect of heterozygosity (a proxy for genetic ancestry) is controlled in the model. Our results indicate that, at least on the studied sample, there is no relationship between socioeconomic stress (as intended as low socioeconomic status) and facial asymmetries.
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Affiliation(s)
- Mirsha Quinto-Sánchez
- Grupo de Investigación en Biología Evolutiva Humana, Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET. Puerto Madryn, Chubut, Argentina
- Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Celia Cintas
- Grupo de Investigación en Biología Evolutiva Humana, Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET. Puerto Madryn, Chubut, Argentina
| | - Caio Cesar Silva de Cerqueira
- Grupo de Investigación en Biología Evolutiva Humana, Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET. Puerto Madryn, Chubut, Argentina
- Ciencia Forense, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, México
- Superintendência da Polícia Técnico-Científica do Estado de São Paulo. Equipe de Perícias Criminalísticas de Ourinhos, São Paulo, Brazil
| | - Virginia Ramallo
- Grupo de Investigación en Biología Evolutiva Humana, Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET. Puerto Madryn, Chubut, Argentina
| | - Victor Acuña-Alonzo
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, United Kingdom
- Escuela Nacional de Antropología e Historia. Instituto Nacional de Antropología e Historia, Ciudad de México, México
| | - Kaustubh Adhikari
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, United Kingdom
| | - Lucía Castillo
- Grupo de Investigación en Biología Evolutiva Humana, Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET. Puerto Madryn, Chubut, Argentina
| | - Jorge Gomez-Valdés
- Posgrado en Antropología Física, Escuela Nacional de Antropología e Historia, Ciudad de México, México
| | - Paola Everardo
- Escuela Nacional de Antropología e Historia. Instituto Nacional de Antropología e Historia, Ciudad de México, México
| | - Francisco De Avila
- Escuela Nacional de Antropología e Historia. Instituto Nacional de Antropología e Historia, Ciudad de México, México
| | - Tábita Hünemeier
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo
| | | | | | - Macarena Fuentes
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, United Kingdom
- Departamento de Técnología Médica, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, Chile
| | - Carla Gallo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Giovani Poletti
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Lavinia Schuler-Faccini
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Maria Cátira Bortolini
- Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Samuel Canizales-Quinteros
- Unidad de Genómica de Poblaciones Aplicada a la Salud, Facultad de Química, UNAM-Instituto Nacional de Medicina Genómica, Ciudad de México, México
| | | | | | - Javier Rosique
- Departamento de Antropología. Facultad de Ciencias Sociales y Humanas. Universidad de Antioquia, Medellín, Colombia
| | - Andrés Ruiz-Linares
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, United Kingdom
- MOE Key Laboratory of Contemporary Anthropology, Fudan University, Shanghai, China
- Aix Marseille Univ, CNRS, EFS, ADES, Marseille, France
| | - Rolando González-José
- Grupo de Investigación en Biología Evolutiva Humana, Instituto Patagónico de Ciencias Sociales y Humanas, Centro Nacional Patagónico, CONICET. Puerto Madryn, Chubut, Argentina
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Henderson AJ, Holzleitner IJ, Talamas SN, Perrett DI. Perception of health from facial cues. Philos Trans R Soc Lond B Biol Sci 2016; 371:rstb.2015.0380. [PMID: 27069057 DOI: 10.1098/rstb.2015.0380] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2015] [Indexed: 11/12/2022] Open
Abstract
Impressions of health are integral to social interactions, yet poorly understood. A review of the literature reveals multiple facial characteristics that potentially act as cues to health judgements. The cues vary in their stability across time: structural shape cues including symmetry and sexual dimorphism alter slowly across the lifespan and have been found to have weak links to actual health, but show inconsistent effects on perceived health. Facial adiposity changes over a medium time course and is associated with both perceived and actual health. Skin colour alters over a short time and has strong effects on perceived health, yet links to health outcomes have barely been evaluated. Reviewing suggested an additional influence of demeanour as a perceptual cue to health. We, therefore, investigated the association of health judgements with multiple facial cues measured objectively from two-dimensional and three-dimensional facial images. We found evidence for independent contributions of face shape and skin colour cues to perceived health. Our empirical findings: (i) reinforce the role of skin yellowness; (ii) demonstrate the utility of global face shape measures of adiposity; and (iii) emphasize the role of affect in facial images with nominally neutral expression in impressions of health.
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Affiliation(s)
- Audrey J Henderson
- School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK
| | - Iris J Holzleitner
- School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK
| | - Sean N Talamas
- School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK
| | - David I Perrett
- School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK
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40
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Coall DA, Tickner M, McAllister LS, Sheppard P. Developmental influences on fertility decisions by women: an evolutionary perspective. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150146. [PMID: 27022073 DOI: 10.1098/rstb.2015.0146] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2016] [Indexed: 01/19/2023] Open
Abstract
Developmental environments are crucial for shaping our life course. Elements of the early social and biological environments have been consistently associated with reproduction in humans. To date, a strong focus has been on the relationship between early stress, earlier menarche and first child birth in women. These associations, found predominately in high-income countries, have been usefully interpreted within life-history theory frameworks. Fertility, on the other hand--a missing link between an individual's early environment, reproductive strategy and fitness--has received little attention. Here, we synthesize this literature by examining the associations between early adversity, age at menarche and fertility and fecundity in women. We examine the evidence that potential mechanisms such as birth weight, childhood body composition, risky health behaviours and developmental influences on attractiveness link the early environment and fecundity and fertility. The evidence that menarche is associated with fertility and fecundity is good. Currently, owing to the small number of correlational studies and mixed methodologies, the evidence that early adversity predicts fecundity and fertility is not conclusive. This area of research is in its infancy; studies examining early adversity and adult fertility decisions that can also examine likely biological, social and psychological pathways present opportunities for future fertility research.
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Affiliation(s)
- D A Coall
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, Western Australia, Australia
| | - M Tickner
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - L S McAllister
- Department of Anthropology, University of California, Santa Barbara, CA 93106, USA
| | - P Sheppard
- Department of Population Health, London School of Hygiene and Tropical Medicine, London, UK
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Danel DP, Dziedzic-Danel A, Kleisner K. Does age difference really matter? Facial markers of biological quality and age difference between husband and wife. HOMO-JOURNAL OF COMPARATIVE HUMAN BIOLOGY 2016; 67:337-47. [PMID: 27238548 DOI: 10.1016/j.jchb.2016.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 02/29/2016] [Indexed: 11/15/2022]
Abstract
Information conveyed by facial attractiveness markers such as averageness, bilateral symmetry, and secondary sexual characteristics may play an important adaptive role in human sexual selection. Nonetheless, mate choice also relies on other non-physical characteristics such as, for instance, an individual's age. Women prefer and enter in relationships with older partners, whereas in men the inverse relation is observed. Surprisingly, the link between facial morphological markers of biological quality on the one hand and age disparity between partners on the other hand has been as yet subject of very little research. This study aims to fill this gap. We had used facial photographs and demographic data of heterosexual marriages. Facial cues of biological quality, such as averageness, bilateral symmetry, and sexual dimorphism, were digitally measured using geometric morphometric methods and then associated with spouses' age difference. It turned out that a greater age disparity between spouses correlates, in both partners, with higher scores in facial measures which indicate partners' biological quality. One exception is female facial masculinity - generally regarded as an unattractive marker of a low biological quality - which, too, is associated with higher spouse age disparity. In general, our results show that facial symmetry, averageness, and secondary sexual characteristics may play a role in age-dependent mate choice. We suggest that in marriages where the wife is considerably younger than the husband, wife's greater facial masculinity may increase her perceived age and with it, her perceived maturity.
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Affiliation(s)
- D P Danel
- Polish Academy of Sciences, Anthropology Unit in Wroclaw, Podwale 75, 50-449 Wroclaw, Poland.
| | - A Dziedzic-Danel
- Department of Heart Diseases, Wroclaw Medical University, Weigla 5, 50-981 Wroclaw, Poland
| | - K Kleisner
- Department of Philosophy and History of Sciences, Faculty of Sciences, Charles University in Prague, Viničná 7, 128 44 Praha 2, Czech Republic
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42
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Mühlenbeck C, Liebal K, Pritsch C, Jacobsen T. Differences in the Visual Perception of Symmetric Patterns in Orangutans (Pongo pygmaeus abelii) and Two Human Cultural Groups: A Comparative Eye-Tracking Study. Front Psychol 2016; 7:408. [PMID: 27065184 PMCID: PMC4811873 DOI: 10.3389/fpsyg.2016.00408] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/07/2016] [Indexed: 11/27/2022] Open
Abstract
Symmetric structures are of importance in relation to aesthetic preference. To investigate whether the preference for symmetric patterns is unique to humans, independent of their cultural background, we compared two human populations with distinct cultural backgrounds (Namibian hunter-gatherers and German town dwellers) with one species of non-human great apes (Orangutans) in their viewing behavior regarding symmetric and asymmetric patterns in two levels of complexity. In addition, the human participants were asked to give their aesthetic evaluation of a subset of the presented patterns. The results showed that humans of both cultural groups fixated on symmetric patterns for a longer period of time, regardless of the pattern’s complexity. On the contrary, Orangutans did not clearly differentiate between symmetric and asymmetric patterns, but were much faster in processing the presented stimuli and scanned the complete screen, while both human groups rested on the symmetric pattern after a short scanning time. The aesthetic evaluation test revealed that the fixation preference for symmetric patterns did not match with the aesthetic evaluation in the Hai//om group, whereas in the German group aesthetic evaluation was in accordance with the fixation preference in 60 percent of the cases. It can be concluded that humans prefer well-ordered structures in visual processing tasks, most likely because of a positive processing bias for symmetry, which Orangutans did not show in this task, and that, in humans, an aesthetic preference does not necessarily accompany the fixation preference.
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Affiliation(s)
- Cordelia Mühlenbeck
- Department of Education and Psychology, Freie Universität Berlin Berlin, Germany
| | - Katja Liebal
- Department of Education and Psychology, Freie Universität Berlin Berlin, Germany
| | - Carla Pritsch
- Department of Education and Psychology, Freie Universität BerlinBerlin, Germany; Graduate School "Languages of Emotion," Freie Universität BerlinBerlin, Germany
| | - Thomas Jacobsen
- Experimental Psychology Unit, Helmut Schmidt University - University of the Federal Armed Forces Hamburg Hamburg, Germany
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43
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Analyzing Fluctuating Asymmetry with Geometric Morphometrics: Concepts, Methods, and Applications. Symmetry (Basel) 2015. [DOI: 10.3390/sym7020843] [Citation(s) in RCA: 208] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Plasmodium infections and fluctuating asymmetry among children and teenagers from Senegal. INFECTION GENETICS AND EVOLUTION 2015; 32:97-101. [PMID: 25725158 DOI: 10.1016/j.meegid.2015.02.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 11/22/2022]
Abstract
Although fluctuating asymmetry is a sensitive indicator of stress, its links with health remains controversial, especially in humans. Here, we explored for the first time the association between fluctuating asymmetry and malaria infections in humans, from 107 participants involved in a long term medical survey in Senegal. No clear relationship was detected. Depending on traits considered, associations were not significant, or (marginally) significant but not in the same directions. We discuss the possible reasons for the global weakness of the signals detected in this study.
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