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Levine H, Jørgensen N, Martino-Andrade A, Mendiola J, Weksler-Derri D, Jolles M, Pinotti R, Swan SH. Temporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries. Hum Reprod Update 2023; 29:157-176. [PMID: 36377604 DOI: 10.1093/humupd/dmac035] [Citation(s) in RCA: 118] [Impact Index Per Article: 118.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Numerous studies have reported declines in semen quality and other markers of male reproductive health. Our previous meta-analysis reported a significant decrease in sperm concentration (SC) and total sperm count (TSC) among men from North America-Europe-Australia (NEA) based on studies published during 1981-2013. At that time, there were too few studies with data from South/Central America-Asia-Africa (SAA) to reliably estimate trends among men from these continents. OBJECTIVE AND RATIONALE The aim of this study was to examine trends in sperm count among men from all continents. The broader implications of a global decline in sperm count, the knowledge gaps left unfilled by our prior analysis and the controversies surrounding this issue warranted an up-to-date meta-analysis. SEARCH METHODS We searched PubMed/MEDLINE and EMBASE to identify studies of human SC and TSC published during 2014-2019. After review of 2936 abstracts and 868 full articles, 44 estimates of SC and TSC from 38 studies met the protocol criteria. Data were extracted on semen parameters (SC, TSC, semen volume), collection year and covariates. Combining these new data with data from our previous meta-analysis, the current meta-analysis includes results from 223 studies, yielding 288 estimates based on semen samples collected 1973-2018. Slopes of SC and TSC were estimated as functions of sample collection year using simple linear regression as well as weighted meta-regression. The latter models were adjusted for predetermined covariates and examined for modification by fertility status (unselected by fertility versus fertile), and by two groups of continents: NEA and SAA. These analyses were repeated for data collected post-2000. Multiple sensitivity analyses were conducted to examine assumptions, including linearity. OUTCOMES Overall, SC declined appreciably between 1973 and 2018 (slope in the simple linear model: -0.87 million/ml/year, 95% CI: -0.89 to -0.86; P < 0.001). In an adjusted meta-regression model, which included two interaction terms [time × fertility group (P = 0.012) and time × continents (P = 0.058)], declines were seen among unselected men from NEA (-1.27; -1.78 to -0.77; P < 0.001) and unselected men from SAA (-0.65; -1.29 to -0.01; P = 0.045) and fertile men from NEA (-0.50; -1.00 to -0.01; P = 0.046). Among unselected men from all continents, the mean SC declined by 51.6% between 1973 and 2018 (-1.17: -1.66 to -0.68; P < 0.001). The slope for SC among unselected men was steeper in a model restricted to post-2000 data (-1.73: -3.23 to -0.24; P = 0.024) and the percent decline per year doubled, increasing from 1.16% post-1972 to 2.64% post-2000. Results were similar for TSC, with a 62.3% overall decline among unselected men (-4.70 million/year; -6.56 to -2.83; P < 0.001) in the adjusted meta-regression model. All results changed only minimally in multiple sensitivity analyses. WIDER IMPLICATIONS This analysis is the first to report a decline in sperm count among unselected men from South/Central America-Asia-Africa, in contrast to our previous meta-analysis that was underpowered to examine those continents. Furthermore, data suggest that this world-wide decline is continuing in the 21st century at an accelerated pace. Research on the causes of this continuing decline and actions to prevent further disruption of male reproductive health are urgently needed.
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Affiliation(s)
- Hagai Levine
- Braun School of Public Health and Community Medicine, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Niels Jørgensen
- Department of Growth and Reproduction, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,International Center for Research and Research Training in Endocrine Disruption of Male Reproduction and Child Health (EDMaRC), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - Jaime Mendiola
- Division of Preventive Medicine and Public Health, University of Murcia School of Medicine and Biomedical Research Institute of Murcia (IMIB-Arrixaca-UMU), Murcia, Spain
| | - Dan Weksler-Derri
- Clalit Health Services, Kiryat Ono, Israel.,Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Maya Jolles
- Braun School of Public Health and Community Medicine, Hadassah Medical Center, The Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachel Pinotti
- Gustave L. and Janet W. Levy Library, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Shanna H Swan
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Nicolas SCA, Welling LLM. A Preliminary Investigation Into Women’s Sexual Risk-taking That Could Lead to Unintended Pregnancy. EVOLUTIONARY PSYCHOLOGICAL SCIENCE 2022. [DOI: 10.1007/s40806-022-00319-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Fiala V, Třebický V, Pazhoohi F, Leongómez JD, Tureček P, Saribay SA, Akoko RM, Kleisner K. Facial attractiveness and preference of sexual dimorphism: A comparison across five populations. EVOLUTIONARY HUMAN SCIENCES 2021; 3:e38. [PMID: 37588529 PMCID: PMC10427909 DOI: 10.1017/ehs.2021.33] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Despite intensive research, evolutionary psychology has not yet reached a consensus regarding the association between sexual dimorphism and attractiveness. This study examines associations between perceived and morphological facial sexual dimorphism and perceived attractiveness in samples from five distant countries (Cameroon, Colombia, Czechia, Iran and Turkey). We also examined possible moderating effects of skin lightness, averageness, age, body mass and facial width. Our results suggest that in all samples, women's perceived femininity was positively related to their perceived attractiveness. Women found perceived masculinity in men attractive only in Czechia and Colombia, two distant populations. The association between perceived sexual dimorphism and attractiveness is thus potentially universal only for women. Across populations, morphological sexual dimorphism and averageness are not universally associated with either perceived facial sexual dimorphism or attractiveness. With our exploratory approach, results highlight the need for control of which measure of sexual dimorphism is used (perceived or measured) because they affect perceived attractiveness differently. Morphological averageness and sexual dimorphism are not good predictors of perceived attractiveness. It is noted that future studies should use samples from multiple populations to allow for identification of specific effects of local environmental and socioeconomic conditions on preferred traits in unmanipulated local facial stimuli.
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Affiliation(s)
- Vojtěch Fiala
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| | - Vít Třebický
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
- Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic
| | - Farid Pazhoohi
- Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Juan David Leongómez
- Human Behaviour Laboratory, Faculty of Psychology, Universidad El Bosque, Bogota, Colombia
| | - Petr Tureček
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| | - S. Adil Saribay
- Department of Psychology, Kadir Has University, Istanbul, Turkey
| | - Robert Mbe Akoko
- Department of Communication and Development Studies, University of Bamenda, Cameroon
| | - Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
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DeLecce T, Fink B, Shackelford T, Abed MG. No Evidence for a Relationship between Intelligence and Ejaculate Quality. EVOLUTIONARY PSYCHOLOGY 2020; 18:1474704920960450. [PMID: 32945185 PMCID: PMC10358410 DOI: 10.1177/1474704920960450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 09/01/2020] [Indexed: 11/17/2022] Open
Abstract
Genetic quality may be expressed through many traits simultaneously, and this would suggest a phenotype-wide fitness factor. In humans, intelligence has been positively associated with several potential indicators of genetic quality, including ejaculate quality. We conducted a conceptual replication of one such study by investigating the relationship between intelligence (assessed by the Raven Advanced Progressive Matrices Test-Short Form) and ejaculate quality (indexed by sperm count, sperm concentration, and sperm motility) in a sample of 41 men (ages ranging 18 to 33 years; M = 23.33; SD = 3.60). By self-report, participants had not had a vasectomy, and had never sought infertility treatment. We controlled for several covariates known to affect ejaculate quality (e.g., abstinence duration before providing an ejaculate) and found no statistically significant relationship between intelligence and ejaculate quality; our findings, therefore, do not match those of Arden, Gottfredson, Miller et al. or those of previous studies. We discuss limitations of this study and the general research area and highlight the need for future research in this area, especially the need for larger data sets to address questions around phenotypic quality and ejaculate quality.
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Affiliation(s)
- Tara DeLecce
- Department of Psychology, Oakland University, Rochester, MI, USA
| | - Bernhard Fink
- Department of Evolutionary Anthropology, University of Vienna, Austria
- Biosocial Science Information, Biedermannsdorf, Austria
- Department of Behavioral Ecology, University of Goettingen, Germany
| | - Todd Shackelford
- Department of Psychology, Oakland University, Rochester, MI, USA
| | - Mohaned G. Abed
- King Abdulaziz University, Educational Graduate Studies, Al Ehtifalat St, Jeddah 21589, Saudi Arabia
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Foo YZ, Simmons LW, Peters M, Rhodes G. Perceived physical strength in men is attractive to women but may come at a cost to ejaculate quality. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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7
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Levine H, Jørgensen N, Martino-Andrade A, Mendiola J, Weksler-Derri D, Mindlis I, Pinotti R, Swan SH. Temporal trends in sperm count: a systematic review and meta-regression analysis. Hum Reprod Update 2018; 23:646-659. [PMID: 28981654 DOI: 10.1093/humupd/dmx022] [Citation(s) in RCA: 705] [Impact Index Per Article: 117.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 06/28/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Reported declines in sperm counts remain controversial today and recent trends are unknown. A definitive meta-analysis is critical given the predictive value of sperm count for fertility, morbidity and mortality. OBJECTIVE AND RATIONALE To provide a systematic review and meta-regression analysis of recent trends in sperm counts as measured by sperm concentration (SC) and total sperm count (TSC), and their modification by fertility and geographic group. SEARCH METHODS PubMed/MEDLINE and EMBASE were searched for English language studies of human SC published in 1981-2013. Following a predefined protocol 7518 abstracts were screened and 2510 full articles reporting primary data on SC were reviewed. A total of 244 estimates of SC and TSC from 185 studies of 42 935 men who provided semen samples in 1973-2011 were extracted for meta-regression analysis, as well as information on years of sample collection and covariates [fertility group ('Unselected by fertility' versus 'Fertile'), geographic group ('Western', including North America, Europe Australia and New Zealand versus 'Other', including South America, Asia and Africa), age, ejaculation abstinence time, semen collection method, method of measuring SC and semen volume, exclusion criteria and indicators of completeness of covariate data]. The slopes of SC and TSC were estimated as functions of sample collection year using both simple linear regression and weighted meta-regression models and the latter were adjusted for pre-determined covariates and modification by fertility and geographic group. Assumptions were examined using multiple sensitivity analyses and nonlinear models. OUTCOMES SC declined significantly between 1973 and 2011 (slope in unadjusted simple regression models -0.70 million/ml/year; 95% CI: -0.72 to -0.69; P < 0.001; slope in adjusted meta-regression models = -0.64; -1.06 to -0.22; P = 0.003). The slopes in the meta-regression model were modified by fertility (P for interaction = 0.064) and geographic group (P for interaction = 0.027). There was a significant decline in SC between 1973 and 2011 among Unselected Western (-1.38; -2.02 to -0.74; P < 0.001) and among Fertile Western (-0.68; -1.31 to -0.05; P = 0.033), while no significant trends were seen among Unselected Other and Fertile Other. Among Unselected Western studies, the mean SC declined, on average, 1.4% per year with an overall decline of 52.4% between 1973 and 2011. Trends for TSC and SC were similar, with a steep decline among Unselected Western (-5.33 million/year, -7.56 to -3.11; P < 0.001), corresponding to an average decline in mean TSC of 1.6% per year and overall decline of 59.3%. Results changed minimally in multiple sensitivity analyses, and there was no statistical support for the use of a nonlinear model. In a model restricted to data post-1995, the slope both for SC and TSC among Unselected Western was similar to that for the entire period (-2.06 million/ml, -3.38 to -0.74; P = 0.004 and -8.12 million, -13.73 to -2.51, P = 0.006, respectively). WIDER IMPLICATIONS This comprehensive meta-regression analysis reports a significant decline in sperm counts (as measured by SC and TSC) between 1973 and 2011, driven by a 50-60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand. Because of the significant public health implications of these results, research on the causes of this continuing decline is urgently needed.
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Affiliation(s)
- Hagai Levine
- Braun School of Public Health and Community Medicine, Hadassah-Hebrew University, the Hebrew University Center of Excellence in Agriculture and Environmental Health, Ein Kerem Campus, PO BOX 12272, Jerusalem 9110202, Israel.,Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Niels Jørgensen
- University Department of Growth and Reproduction, University of Copenhagen, Rigshospitalet, CopenhagenDK-2100, Denmark
| | - Anderson Martino-Andrade
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Department of Physiology, Federal University of Parana, Curitiba 81531-980, Brazil
| | - Jaime Mendiola
- Division of Preventive Medicine and Public Health, University of Murcia School of Medicine and Biomedical Research Institute of Murcia (IMIB-Arrixaca-UMU), Murcia30100, Spain
| | - Dan Weksler-Derri
- Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva6676814, Israel
| | - Irina Mindlis
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY10029, USA
| | - Rachel Pinotti
- Gustave L. and Janet W. Levy Library, Icahn School of Medicine at Mount Sinai, New York, NY10029, USA
| | - Shanna H Swan
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY10029, USA
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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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9
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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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10
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Hill MQ, Streuber S, Hahn CA, Black MJ, O’Toole AJ. Creating Body Shapes From Verbal Descriptions by Linking Similarity Spaces. Psychol Sci 2016; 27:1486-1497. [DOI: 10.1177/0956797616663878] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 07/20/2016] [Indexed: 11/15/2022] Open
Abstract
Brief verbal descriptions of people’s bodies (e.g., “curvy,” “long-legged”) can elicit vivid mental images. The ease with which these mental images are created belies the complexity of three-dimensional body shapes. We explored the relationship between body shapes and body descriptions and showed that a small number of words can be used to generate categorically accurate representations of three-dimensional bodies. The dimensions of body-shape variation that emerged in a language-based similarity space were related to major dimensions of variation computed directly from three-dimensional laser scans of 2,094 bodies. This relationship allowed us to generate three-dimensional models of people in the shape space using only their coordinates on analogous dimensions in the language-based description space. Human descriptions of photographed bodies and their corresponding models matched closely. The natural mapping between the spaces illustrates the role of language as a concise code for body shape that captures perceptually salient global and local body features.
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Affiliation(s)
- Matthew Q. Hill
- School of Behavioral and Brain Sciences, The University of Texas at Dallas
| | | | - Carina A. Hahn
- School of Behavioral and Brain Sciences, The University of Texas at Dallas
| | | | - Alice J. O’Toole
- School of Behavioral and Brain Sciences, The University of Texas at Dallas
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11
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Jeffery AJ, Pham MN, Shackelford TK, Fink B. Does human ejaculate quality relate to phenotypic traits? Am J Hum Biol 2015; 28:318-29. [PMID: 26626022 DOI: 10.1002/ajhb.22805] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 10/08/2015] [Accepted: 10/27/2015] [Indexed: 11/06/2022] Open
Abstract
A given man's phenotype embodies cues of his ancestral ability to effectively defend himself and his kin from harm, to survive adverse conditions, and to acquire status and mating opportunities. In this review, we explore the hypothesis that a man's phenotype also embodies cues to fertility or the probability that an ejaculate will fertilize ova. Female mate choice depends on the ability to discern the quality of a male reproductive partner through his phenotype, and male fertility may be among the traits that females have evolved to detect. A female who selects as mates males that deliver higher quality ejaculates will, on average, be more fecund than her competitors. Data on several non-human species demonstrate correlations between ejaculate quality and secondary sexual characteristics that inform female mate choice, suggesting that females may select mates in part on the basis of fertility. While the non-human literature on this topic has advanced, the human literature remains limited in scope and there is no clear consensus on appropriate methodologies or theoretical positions. We provide a comprehensive review and meta-analysis of this literature, and conclude by proposing solutions to the many issues that impede progress in the field. In the process, we hope to encourage interest and insight from investigators in other areas of human mating and reproductive biology. Am. J. Hum. Biol. 28:318-329, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Michael N Pham
- Department of Psychology, Oakland University, Rochester, Michigan, 48307
| | - Todd K Shackelford
- Department of Psychology, Oakland University, Rochester, Michigan, 48307
| | - Bernhard Fink
- Institute of Psychology and Courant Research Center Evolution of Social Behavior, University of Göttingen, Göttingen, Germany
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12
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Tarín JJ, García-Pérez MA, Hamatani T, Cano A. Infertility etiologies are genetically and clinically linked with other diseases in single meta-diseases. Reprod Biol Endocrinol 2015; 13:31. [PMID: 25880215 PMCID: PMC4404574 DOI: 10.1186/s12958-015-0029-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/09/2015] [Indexed: 02/07/2023] Open
Abstract
The present review aims to ascertain whether different infertility etiologies share particular genes and/or molecular pathways with other pathologies and are associated with distinct and particular risks of later-life morbidity and mortality. In order to reach this aim, we use two different sources of information: (1) a public web server named DiseaseConnect ( http://disease-connect.org ) focused on the analysis of common genes and molecular mechanisms shared by diseases by integrating comprehensive omics and literature data; and (2) a literature search directed to find clinical comorbid relationships of infertility etiologies with only those diseases appearing after infertility is manifested. This literature search is performed because DiseaseConnect web server does not discriminate between pathologies emerging before, concomitantly or after infertility is manifested. Data show that different infertility etiologies not only share particular genes and/or molecular pathways with other pathologies but they have distinct clinical relationships with other diseases appearing after infertility is manifested. In particular, (1) testicular and high-grade prostate cancer in male infertility; (2) non-fatal stroke and endometrial cancer, and likely non-fatal coronary heart disease and ovarian cancer in polycystic ovary syndrome; (3) osteoporosis, psychosexual dysfunction, mood disorders and dementia in premature ovarian failure; (4) breast and ovarian cancer in carriers of BRCA1/2 mutations in diminished ovarian reserve; (5) clear cell and endometrioid histologic subtypes of invasive ovarian cancer, and likely low-grade serous invasive ovarian cancer, melanoma and non-Hodgkin lymphoma in endometriosis; and (6) endometrial and ovarian cancer in idiopathic infertility. The present data endorse the principle that the occurrence of a disease (in our case infertility) is non-random in the population and suggest that different infertility etiologies are genetically and clinically linked with other diseases in single meta-diseases. This finding opens new insights for clinicians and reproductive biologists to treat infertility problems using a phenomic approach instead of considering infertility as an isolated and exclusive disease of the reproductive system/hypothalamic-pituitary-gonadal axis. In agreement with a previous validation analysis of the utility of DiseaseConnect web server, the present study does not show a univocal correspondence between common gene expression and clinical comorbid relationship. Further work is needed to untangle the potential genetic, epigenetic and phenotypic relationships that may be present among different infertility etiologies, morbid conditions and physical/cognitive traits.
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Affiliation(s)
- Juan J Tarín
- Department of Functional Biology and Physical Anthropology, Faculty of Biological Sciences, University of Valencia, Burjassot, Valencia, 46100, Spain.
| | - Miguel A García-Pérez
- Department of Genetics, Faculty of Biological Sciences, University of Valencia, Burjassot, Valencia, 46100, Spain.
- Research Unit-INCLIVA, Hospital Clínico de Valencia, Valencia, 46010, Spain.
| | - Toshio Hamatani
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, 160-8582, Japan.
| | - Antonio Cano
- Department of Pediatrics, Obstetrics and Gynecology, Faculty of Medicine, University of Valencia, Valencia, 46010, Spain.
- Service of Obstetrics and Gynecology, University Clinic Hospital, Valencia, 46010, Spain.
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Farrera A, Villanueva M, Quinto-Sánchez M, González-José R. The relationship between facial shape asymmetry and attractiveness in Mexican students. Am J Hum Biol 2014; 27:387-96. [PMID: 25400276 DOI: 10.1002/ajhb.22657] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 09/20/2014] [Accepted: 10/25/2014] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVES It has been postulated that symmetric faces are considered more attractive than asymmetric ones because symmetry may signal high quality due to developmental stability. However, other studies showed that both symmetric and slightly asymmetric faces are considered attractive. Here we aim to explore this discrepancy, beginning with the analysis of the normal prevalence of facial symmetry in a population as a necessary first step prior to any attractiveness assessment. METHODS We collected facial landmarks from two-dimensional digital images of a sample of Mexican individuals (280 females and 285 males aged 18-68 years) that were analyzed using geometric morphometric methods. Then, we chose a subsample of 100 photographs (50 females and 50 males aged 18-27 years) selected to represent a broad range of asymmetrical variation, in order to evaluate attractiveness using a sex-opposite test. Finally, we analyzed the linear correlation between attractiveness and asymmetry. RESULTS We found that every evaluated subject presents some degree of facial asymmetry, and that both fluctuating asymmetry and directional asymmetry were significant (P < 0.0001) components of total facial asymmetry. Fluctuating asymmetry was slightly associated with age (r = 0.0858, P = 0.0414) and there were no differences between geographical regions (P = 0.413). Attractiveness was not correlated to levels of asymmetry in either sex (males: P = 0.0973; females P = 0.7415). CONCLUSIONS Asymmetry was a prevalent feature in the present sample, and preferences for symmetric faces were not operating in the studied population.
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Affiliation(s)
- Arodi Farrera
- Departamento de Antropología Física, Instituto de Investigaciones Antropológicas, Universidad Nacional Autónoma de México, Distrito Federal, México
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14
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Soler C, Kekäläinen J, Núñez M, Sancho M, Álvarez JG, Núñez J, Yaber I, Gutiérrez R. Male facial attractiveness and masculinity may provide sex- and culture-independent cues to semen quality. J Evol Biol 2014; 27:1930-8. [PMID: 25056484 DOI: 10.1111/jeb.12446] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 06/10/2014] [Accepted: 06/17/2014] [Indexed: 11/30/2022]
Abstract
Phenotype-linked fertility hypothesis (PLFH) predicts that male secondary sexual traits reveal honest information about male fertilization ability. However, PLFH has rarely been studied in humans. The aim of the present study was to test PLFH in humans and to investigate whether potential ability to select fertile partners is independent of sex or cultural background. We found that on the contrary to the hypothesis, facial masculinity was negatively associated with semen quality. As increased levels of testosterone have been demonstrated to impair sperm production, this finding may indicate a trade-off between investments in secondary sexual signalling (i.e. facial masculinity) and fertility or status-dependent differences in investments in semen quality. In both sexes and nationalities (Spanish and Colombian), ranked male facial attractiveness predicted male semen quality. However, Spanish males and females estimated facial images generally more attractive (gave higher ranks) than Colombian raters, and in both nationalities, males gave higher ranks than females. This suggests that male facial cues may provide culture- and sex-independent information about male fertility. However, our results also indicate that humans may be more sensitive to facial attractiveness cues within their own populations and also that males may generally overestimate the attractiveness of other men to females.
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Affiliation(s)
- C Soler
- Departament de Biologia Funcional i Antropologia Física, Universitat de València, Burjassot, Spain
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15
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Gilani SZ, Rooney K, Shafait F, Walters M, Mian A. Geometric facial gender scoring: objectivity of perception. PLoS One 2014; 9:e99483. [PMID: 24923319 PMCID: PMC4055752 DOI: 10.1371/journal.pone.0099483] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 05/15/2014] [Indexed: 11/18/2022] Open
Abstract
Gender score is the cognitive judgement of the degree of masculinity or femininity of a face which is considered to be a continuum. Gender scores have long been used in psychological studies to understand the complex psychosocial relationships between people. Perceptual scores for gender and attractiveness have been employed for quality assessment and planning of cosmetic facial surgery. Various neurological disorders have been linked to the facial structure in general and the facial gender perception in particular. While, subjective gender scoring by human raters has been a tool of choice for psychological studies for many years, the process is both time and resource consuming. In this study, we investigate the geometric features used by the human cognitive system in perceiving the degree of masculinity/femininity of a 3D face. We then propose a mathematical model that can mimic the human gender perception. For our experiments, we obtained 3D face scans of 64 subjects using the 3dMDface scanner. The textureless 3D face scans of the subjects were then observed in different poses and assigned a gender score by 75 raters of a similar background. Our results suggest that the human cognitive system employs a combination of Euclidean and geodesic distances between biologically significant landmarks of the face for gender scoring. We propose a mathematical model that is able to automatically assign an objective gender score to a 3D face with a correlation of up to 0.895 with the human subjective scores.
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Affiliation(s)
- Syed Zulqarnain Gilani
- School of Computer Science and Software Engineering, The University of Western Australia, Perth, Western Australia
- * E-mail:
| | - Kathleen Rooney
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Perth, Western Australia
| | - Faisal Shafait
- School of Computer Science and Software Engineering, The University of Western Australia, Perth, Western Australia
| | - Mark Walters
- Cranio-MaxilloFacial Unit, Princess Margaret Hospital for Children, Perth, Western Australia
| | - Ajmal Mian
- School of Computer Science and Software Engineering, The University of Western Australia, Perth, Western Australia
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16
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Leivers S, Rhodes G, Simmons LW. Context-dependent relationship between a composite measure of men’s mate value and ejaculate quality. Behav Ecol 2014. [DOI: 10.1093/beheco/aru093] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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17
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Wood W, Kressel L, Joshi PD, Louie B. Meta-Analysis of Menstrual Cycle Effects on Women’s Mate Preferences. EMOTION REVIEW 2014. [DOI: 10.1177/1754073914523073] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In evolutionary psychology predictions, women’s mate preferences shift between fertile and nonfertile times of the month to reflect ancestral fitness benefits. Our meta-analytic test involving 58 independent reports (13 unpublished, 45 published) was largely nonsupportive. Specifically, fertile women did not especially desire sex in short-term relationships with men purported to be of high genetic quality (i.e., high testosterone, masculinity, dominance, symmetry). The few significant preference shifts appeared to be research artifacts. The effects declined over time in published work, were limited to studies that used broader, less precise definitions of the fertile phase, and were found only in published research.
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Affiliation(s)
- Wendy Wood
- Department of Psychology, University of Southern California, USA
| | - Laura Kressel
- Department of Psychology, University of Southern California, USA
| | | | - Brian Louie
- Department of Psychology, University of Southern California, USA
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18
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Dixson BJ, Grimshaw GM, Ormsby DK, Dixson AF. Eye-tracking women’s preferences for men’s somatotypes. EVOL HUM BEHAV 2014. [DOI: 10.1016/j.evolhumbehav.2013.10.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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19
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20
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21
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Simmons LW, Peters M, Rhodes G. Low pitched voices are perceived as masculine and attractive but do they predict semen quality in men? PLoS One 2011; 6:e29271. [PMID: 22216228 PMCID: PMC3244455 DOI: 10.1371/journal.pone.0029271] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 11/23/2011] [Indexed: 11/18/2022] Open
Abstract
Women find masculinity in men's faces, bodies, and voices attractive, and women's preferences for men's masculine features are thought to be biological adaptations for finding a high quality mate. Fertility is an important aspect of mate quality. Here we test the phenotype-linked fertility hypothesis, which proposes that male secondary sexual characters are positively related to semen quality, allowing females to obtain direct benefits from mate choice. Specifically, we examined women's preferences for men's voice pitch, and its relationship with men's semen quality. Consistent with previous voice research, women judged lower pitched voices as more masculine and more attractive. However men with lower pitched voices did not have better semen quality. On the contrary, men whose voices were rated as more attractive tended to have lower concentrations of sperm in their ejaculate. These data are more consistent with a trade off between sperm production and male investment in competing for and attracting females, than with the phenotype-linked fertility hypothesis.
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Affiliation(s)
- Leigh W Simmons
- Centre for Evolutionary Biology, School of Animal Biology (M092), University of Western Australia, Crawley, Western Australia, Australia.
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22
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O'Connor JJ, Re DE, Feinberg DR. Voice Pitch Influences Perceptions of Sexual Infidelity. EVOLUTIONARY PSYCHOLOGY 2011. [DOI: 10.1177/147470491100900109] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Sexual infidelity can be costly to members of both the extra-pair and the paired couple. Thus, detecting infidelity risk is potentially adaptive if it aids in avoiding cuckoldry or loss of parental and relationship investment. Among men, testosterone is inversely related to voice pitch, relationship and offspring investment, and is positively related to the pursuit of short-term relationships, including extra-pair sex. Among women, estrogen is positively related to voice pitch, attractiveness, and the likelihood of extra-pair involvement. Although prior work has demonstrated a positive relationship between men's testosterone levels and infidelity, this study is the first to investigate attributions of infidelity as a function of sexual dimorphism in male and female voices. We found that men attributed high infidelity risk to feminized women's voices, but not significantly more often than did women. Women attributed high infidelity risk to masculinized men's voices at significantly higher rates than did men. These data suggest that voice pitch is used as an indicator of sexual strategy in addition to underlying mate value. The aforementioned attributions may be adaptive if they prevent cuckoldry and/or loss of parental and relationship investment via avoidance of partners who may be more likely to be unfaithful.
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Affiliation(s)
- Jillian J.M. O'Connor
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Canada
| | - Daniel E. Re
- School of Psychology, University of St Andrews, Scotland
| | - David R. Feinberg
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Canada
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23
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Gangestad SW, Thornhill R, Garver-Apgar CE. Men's facial masculinity predicts changes in their female partners' sexual interests across the ovulatory cycle, whereas men's intelligence does not. EVOL HUM BEHAV 2010. [DOI: 10.1016/j.evolhumbehav.2010.06.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Jokela M. Physical attractiveness and reproductive success in humans: Evidence from the late 20 century United States. EVOL HUM BEHAV 2009; 30:342-350. [PMID: 21151758 DOI: 10.1016/j.evolhumbehav.2009.03.006] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Physical attractiveness has been associated with mating behavior, but its role in reproductive success of contemporary humans has received surprisingly little attention. In the Wisconsin Longitudinal Study (1244 women, 997 men born between 1937 and 1940) we examined whether attractiveness assessed from photographs taken at age ~18 predicted the number of biological children at age 53-56. In women, attractiveness predicted higher reproductive success in a nonlinear fashion, so that attractive (second highest quartile) women had 16% and very attractive (highest quartile) women 6% more children than their less attractive counterparts. In men, there was a threshold effect so that men in the lowest attractiveness quartile had 13% fewer children than others who did not differ from each other in the average number of children. These associations were partly but not completely accounted for by attractive participants' increased marriage probability. A linear regression analysis indicated relatively weak directional selection gradient for attractiveness (β=0.06 in women, β=0.07 in men). These findings indicate that physical attractiveness may be associated with reproductive success in humans living in industrialized settings.
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Affiliation(s)
- Markus Jokela
- Department of Psychology, University of Helsinki, Helsinki, Finland
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25
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Dowling DK, Simmons LW. Reactive oxygen species as universal constraints in life-history evolution. Proc Biol Sci 2009; 276:1737-45. [PMID: 19324792 PMCID: PMC2674489 DOI: 10.1098/rspb.2008.1791] [Citation(s) in RCA: 462] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Evolutionary theory is firmly grounded on the existence of trade-offs between life-history traits, and recent interest has centred on the physiological mechanisms underlying such trade-offs. Several branches of evolutionary biology, particularly those focusing on ageing, immunological and sexual selection theory, have implicated reactive oxygen species (ROS) as profound evolutionary players. ROS are a highly reactive group of oxygen-containing molecules, generated as common by-products of vital oxidative enzyme complexes. Both animals and plants appear to intentionally harness ROS for use as molecular messengers to fulfil a wide range of essential biological processes. However, at high levels, ROS are known to exert very damaging effects through oxidative stress. For these reasons, ROS have been suggested to be important mediators of the cost of reproduction, and of trade-offs between metabolic rate and lifespan, and between immunity, sexual ornamentation and sperm quality. In this review, we integrate the above suggestions into one life-history framework, and review the evidence in support of the contention that ROS production will constitute a primary and universal constraint in life-history evolution.
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Affiliation(s)
- Damian K Dowling
- School of Animal Biology (M092), Centre for Evolutionary Biology, The University of Western Australia, Crawley, Western Australia 6009, Australia.
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26
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Peters M, Simmons LW, Rhodes G. Preferences across the menstrual cycle for masculinity and symmetry in photographs of male faces and bodies. PLoS One 2009; 4:e4138. [PMID: 19127295 PMCID: PMC2607552 DOI: 10.1371/journal.pone.0004138] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Accepted: 11/28/2008] [Indexed: 11/19/2022] Open
Abstract
Background Previous studies have shown that women increase their preference for masculinity during the fertile phase of the menstrual cycle. Evidence for a similar preference shift for symmetry is equivocal. These studies have required participants to choose between subtle variations in computer-generated stimuli, and preferences for more natural stimuli have not been investigated. Methodology/Principal Findings Our study employed photographs of individual males to investigate women's preferences for face and body masculinity and symmetry across the menstrual cycle. We collected attractiveness ratings from 25 normally cycling women at high- and low-fertility days of the menstrual cycle. Attractiveness ratings made by these women were correlated with independent ratings of masculinity and symmetry provided by different sets of raters. We found no evidence for any cyclic shift in female preferences. Correlations between attractiveness and masculinity, and attractiveness and symmetry did not differ significantly between high- and low-fertility test sessions. Furthermore, there was no significant difference between high- and low-fertility ratings of attractiveness. Conclusions These results suggest that a menstrual cycle shift in visual preferences for masculinity and symmetry may be too subtle to influence responses to real faces and bodies, and subsequent mate-choice decisions.
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Affiliation(s)
- Marianne Peters
- Centre for Evolutionary Biology, School of Animal Biology, University of Western Australia, Crawley, Australia
- School of Psychology, University of Western Australia, Crawley, Australia
- * E-mail:
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Animal Biology, University of Western Australia, Crawley, Australia
| | - Gillian Rhodes
- School of Psychology, University of Western Australia, Crawley, Australia
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27
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Abstract
Facial symmetry, averageness, sexual dimorphism, and skin colour/texture all serve as cues to attractiveness, but their role in the perception of health is less clear. This ambiguity could reflect the fact that these facial traits are not the only cues to health. We propose that adiposity is an important, but thus far disregarded, facial cue to health. Our results demonstrate two important prerequisites for any health cue. First, we show that facial adiposity, or the perception of weight in the face, significantly predicts perceived health and attractiveness. Second, we show that perceived facial adiposity is significantly associated with measures of cardiovascular health and reported infections. Perceived facial adiposity, or a correlate thereof, is therefore an important and valid cue to health that should be included in future studies.
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Affiliation(s)
- Vinet Coetzee
- Perception Laboratory, School of Psychology, University of St Andrews, St Mary's Quad, South Street, St Andrews, Fife KY16 9JP, Scotland, UK
| | - David I Perrett
- Perception Laboratory, School of Psychology, University of St Andrews, St Mary's Quad, South Street, St Andrews, Fife KY16 9JP, Scotland, UK
| | - Ian D Stephen
- Perception Laboratory, School of Psychology, University of St Andrews, St Mary's Quad, South Street, St Andrews, Fife KY16 9JP, Scotland, UK
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28
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Facial attractiveness: Variation, adaptiveness and consequences of facial preferences. ANTHROPOLOGICAL REVIEW 2008. [DOI: 10.2478/v10044-008-0012-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Facial attractiveness: Variation, adaptiveness and consequences of facial preferencesThis review embraces the following topics: intra- and inter-populational variation of facial preferences, relationship between facial attractiveness and mate value, biological and social effects of the perception of facial attractiveness, credibility of the adaptive perspective on facial preferences, and the phylogeny of facial attractiveness. Its main conclusions are as follows: (1) Many sources of inter-individual variation in assessments of facial attractiveness have been identified, e.g., the age, sex, biological quality, physiological state, personality, and living situation of the judge, as well as previously observed faces, physical similarity of the focal face to the judge's face, and acquaintance with and knowledge of the face owner. (2) Inter-populational consistency in perception of facial attractiveness is substantial and possesses both a biological and a cultural basis. (3) Facial attractiveness is a reliable cue to biological quality of the face owner, e.g., better parasite resistance, physical fitness, reproductive fitness, longevity, less mutational load, higher intelligence and better mental health. (4) Facially attractive people have more sexual partners, marry at a younger age, and remain single less frequently. Thereby, they have higher reproductive success than unattractive individuals. (5) As a whole, research supports the thesis that facial preferences are adaptive, that is, they evolved during the course of biological evolution because they assisted an individual in choosing a mate with good genes or a good personality.
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