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Chen N, Hidaka S, Ishii N, Wada M. People with higher systemizing traits have wider right hands. Front Psychiatry 2024; 15:1404559. [PMID: 39301224 PMCID: PMC11411187 DOI: 10.3389/fpsyt.2024.1404559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 08/19/2024] [Indexed: 09/22/2024] Open
Abstract
Introduction Various genetic mutations have been implicated in autism spectrum disorder (ASD). Some candidate genes for ASD are known to be related to signal transduction and may be involved in hand development as well as neurodevelopment. Therefore, although subtle, anatomical variations in hand configurations may be observed in individuals with ASD. However, except for research on the finger ratio, which has been suggested to be related to prenatal sex hormone exposure, only few studies have been conducted. Given the spectrum characteristics of ASD, we explored whether hand configurations are associated with ASD-related traits in the general population. Methods Photographs of the dorsal surface of each hand were obtained, and the distances between the metacarpophalangeal joints and finger lengths were measured. The Autism Spectrum Quotient, Empathy Quotient, and Systemizing Quotient were used to evaluate ASD-related traits. Results We found a significant positive correlation between the aspect ratio of the right hand and the Systemizing Quotient score: individuals with a larger width relative to the finger length showed more systemizing traits. Discussion These findings suggest that gene polymorphisms or prenatal sex hormone exposure may underlie the relationship between systemizing traits and hand configurations.
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Affiliation(s)
- Na Chen
- Developmental Disorders Section, Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Saitama, Japan
| | - Souta Hidaka
- Department of Psychology, Rikkyo University, Niiza, Saitama, Japan
- Department of Psychology, Faculty of Human Sciences, Sophia University, Chiyoda, Tokyo, Japan
| | - Naomi Ishii
- Developmental Disorders Section, Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Saitama, Japan
| | - Makoto Wada
- Developmental Disorders Section, Department of Rehabilitation for Brain Functions, Research Institute of National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Saitama, Japan
- Information and Support Center for Persons with Developmental Disorders, National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Saitama, Japan
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Ernsten L, Körner LM, Heil M, Schaal NK. The association between 2D:4D digit ratio and sex-typed play in children with and without siblings. Sci Rep 2024; 14:15231. [PMID: 38956189 PMCID: PMC11219774 DOI: 10.1038/s41598-024-65739-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 06/24/2024] [Indexed: 07/04/2024] Open
Abstract
The 2D:4D digit ratio is commonly used as a surrogate possibly reflecting prenatal testosterone levels. Indirect evidence comes from studies investigating the association between 2D:4D and human characteristics that likely relate to prenatal testosterone. In children, sex-typed play reveals large sex differences early in development and an influence of prenatal testosterone is likely. Findings on the association between 2D:4D and children's sex-typed play are heterogeneous and other influences on the development of sex-typed play have been suggested, most of all social influences like siblings, their sex and birth order. The current study examined the association between right and left 2D:4D, a proposed surrogate for prenatal testosterone exposure, which was assessed in right and left hands of N = 505 6-month-old children, and sex-typed play behavior, which was evaluated 3.5 years later using the Pre-School Activities Inventory (PSAI), and the influence of siblings. To capture differential effects of siblings' sex and birth order, dummy-coded variables were used reflecting having no siblings as well as older or younger sisters or brothers. Multiple regression models were used to investigate the association between PSAI scores and sex, right and left 2D:4D, being a singleton as well as having an older or younger sister or brother. It was shown that sex and having an older brother were significant predictors for sex-typed play. Effects were further disentangled by conducting separate regression analyses in boys and girls. In boys, a significant association between PSAI scores and having an older brother was revealed, in girls, no significant associations were found. Results are discussed highlighting the non-significant association between 2D:4D and children's sex-typed play, which weakens the applicability of 2D:4D as a surrogate reflecting influences of prenatal T. Further, the importance of social factors like siblings on children's sex-typed play is discussed.
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Affiliation(s)
- Luisa Ernsten
- Faculty of Mathematics and Natural Sciences, Institute of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany.
| | - Lisa M Körner
- Faculty of Mathematics and Natural Sciences, Institute of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany
| | - Martin Heil
- Faculty of Mathematics and Natural Sciences, Institute of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany
| | - Nora K Schaal
- Faculty of Mathematics and Natural Sciences, Institute of Experimental Psychology, Heinrich Heine University, Düsseldorf, Germany
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Kratochvíl L, Havlíček J. The fallacy of global comparisons based on per capita measures. ROYAL SOCIETY OPEN SCIENCE 2024; 11:230832. [PMID: 38511080 PMCID: PMC10951725 DOI: 10.1098/rsos.230832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 01/19/2024] [Accepted: 02/14/2024] [Indexed: 03/22/2024]
Abstract
Media, social scientists and public health researchers often present comparisons across countries, and policy makers use such comparisons to take evidence-based action. For a meaningful comparison among countries, one often needs to normalize the measure for differences in population size. To address this issue, the first choice is usually to calculate per capita ratios. Such ratios, however, normalize the measure for differences in population size directly only under the highly restrictive assumption of a proportional increase of the measure with population size. Violation of this assumption frequently leads to misleading conclusions. We compare per capita ratios with an approach based on regression, a widely used statistical procedure that eliminates many of the problems with ratios and allows for straightforward data interpretation. It turns out that the per capita measures in three global datasets (gross domestic product, COVID-19-related mortality and CO2 production) systematically overestimate values in countries with small populations, while countries with large populations tend to have misleadingly low per capita ratios owing to the large denominators. Unfortunately, despite their biases, comparisons based on per capita ratios are still ubiquitous, and they are used for influential recommendations by various global institutions. Their continued use can cause significant damage when employed as evidence for policy actions and should therefore be replaced by a more scientifically substantiated and informative method, such as a regression-based approach.
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Affiliation(s)
- Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague128 00, Czech Republic
| | - Jan Havlíček
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, Prague128 00, Czech Republic
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Kaur P, Mittal P, Kaur H, Kiran J, Singh S, Medhi R. Gender Determination Using Index and Ring Finger Linear Measurements in North Indian Population: A Cross-Sectional Study. Cureus 2024; 16:e54459. [PMID: 38510912 PMCID: PMC10953610 DOI: 10.7759/cureus.54459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/16/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND In the fields of medico-legal matters and bio-archaeological settings, gender evaluation plays a pivotal role in the initial stages of human identification. Approximately half of the population at risk is excluded when gender is determined, making it the most essential factor for identification. When it comes to medico-legal matters and bio-archaeological settings, gender evaluation is a crucial initial step in human identification. Traditional gender determination procedures, such as skull and pelvic analysis, may be hindered by fragmentary human remains that have been degraded by various forms of inhumation or physical assaults. AIM To investigate sexual dimorphism, this study examined the ratio of index finger length to ring finger length. MATERIALS AND METHOD The lengths of the index and ring fingers were measured and the ratios between them were calculated for both hands separately. Applications of IBM SPSS Statistics for Windows, Version 16.0 (Released 2007; IBM Corp., Armonk, New York, United States) included Student's t-test and Levene's test. RESULTS According to the study, women's index finger-to-ring finger length ratios were much longer than men's. The ratio of index finger to ring finger length was significantly different between the sexes on both sides of the hand (p<0.001). In terms of the right hand, the threshold value was 0.9666 for men and 0.9952 for females, while in terms of the left hand, the values were 0.9638 and 0.9920, respectively. CONCLUSION With an advancing front in this arena on gender determination, the use of digits has become an additional source of support to physical anthropologists for bio-archaeological surveys and to forensic experts for use in medico-legal investigations for fragmentary remains received during investigatory trials.
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Affiliation(s)
- Prabhpreet Kaur
- Department of Oral and Maxillofacial Pathology, Genesis Institute of Dental Sciences and Research, Firozpur, IND
| | - Pratham Mittal
- Department of Oral and Maxillofacial Pathology, Genesis Institute of Dental Sciences and Research, Firozpur, IND
| | - Harleen Kaur
- Department of Oral and Maxillofacial Pathology, Genesis Institute of Dental Sciences and Research, Firozpur, IND
| | - Jyoti Kiran
- Department of Oral and Maxillofacial Surgery, Dantya Clinic Dental & Cosmetic, Chandigarh, IND
| | - Simarjeev Singh
- Department of Oral Medicine and Radiology, Gian Sagar Dental College and Hospital, Patiala, IND
| | - Reeturaj Medhi
- Department of Oral and Maxillofacial Pathology, Vyas Dental College and Hospital, Jodhpur, IND
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Sorokowski P, Kowal M. Relationship between the 2D:4D and prenatal testosterone, adult level testosterone, and testosterone change: Meta-analysis of 54 studies. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:20-38. [PMID: 37795916 DOI: 10.1002/ajpa.24852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/29/2023] [Accepted: 09/12/2023] [Indexed: 10/06/2023]
Abstract
The ratio between the hands' second to the fourth finger (2D:4D) is commonly hypothesized to result from prenatal testosterone. The 2D:4D has also been hypothesized to relate to adult-level testosterone and, more recently, to the testosterone response to a challenging situation. In the present work, we tested these core assumptions. Drawing from, in total, 54 studies and 8077 participants, we investigated whether the 2D:4D is related to adult level testosterone (44 studies), testosterone change (6 studies), and prenatal testosterone (10 studies). We found no evidence of the relationship between the above testosterone types and digit ratios. Furthermore, there was no relationship between testosterone and the right and left 2D:4D, male and female 2D:4D, and the 2D:4D and testosterone measurement (i.e., measured in blood or saliva). However, we found some evidence that prenatal testosterone measured in amniotic fluid (but not cord blood) might be related to the digit ratios-further studies are necessary to validate this observation. In summary, considering the current state of knowledge, any conclusions drawn from the assumption of the digit ratios as the proxy for testosterone (prenatal, adult level, or testosterone change under a challenging situation) warrant great caution.
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Affiliation(s)
| | - Marta Kowal
- IDN Being Human Lab, University of Wrocław, Wrocław, Poland
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Abe T, Abe A, Loenneke JP. Association of changes in grip strength with second digit length adjusted for fourth digit length in young children. Am J Hum Biol 2023; 35:e23901. [PMID: 36998165 DOI: 10.1002/ajhb.23901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 04/01/2023] Open
Abstract
OBJECTIVES The factors involved in changes in grip strength (GS) during growth/development are not well known. Findings from cross-sectional studies have indicated that digit lengths are associated with physical fitness, including GS. This study aimed to investigate the association of changes in GS over 1 year and the second (2D) and fourth (4D) digit lengths in young children using the 4D as a covariate. METHODS One hundred and three young children (54 boys and 49 girls) performed maximum voluntary GS and ultrasound-measured forearm muscle thickness measurements in the right hand. All participants completed the first measurement and underwent a second measurement 1 year after the first one. The 2D and 4D were taken on the palmar surface of the outstretched right hand at the second measurement. RESULTS The 2D was inversely associated with the change in GS (B = -2.1, p = 0.023) adjusted for all covariates. Girls had numerically lower adjusted changes in grip strength, although this was not statistically significant [-0.61 (-1.2, 0.02) kg]. When sex was removed from the model, the 2D remained inversely associated with the change in GS (B = -2.39, p = 0.011). Finally, when only adjusting for the 4D, the 2D was inversely associated with the change in GS (B = -3.07, p = 0.004). CONCLUSION This study documented the association between changes in GS over 1 year and digit lengths in young children. The difference in children's digit length needs to be recognized as a factor involved in weak GS in children.
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Affiliation(s)
- Takashi Abe
- Institute of Health and Sports Science & Medicine, Juntendo University, Inzai-shi, Chiba, 270-1695, Japan
- Division of Children's Health and Exercise Research, Institute of Trainology, Fukuoka-shi, Fukuoka, 814-0001, Japan
| | - Akemi Abe
- Division of Children's Health and Exercise Research, Institute of Trainology, Fukuoka-shi, Fukuoka, 814-0001, Japan
| | - Jeremy P Loenneke
- Department of Health, Exercise Science, and Recreation Management, Kevser Ermin Applied Physiology Laboratory, The University of Mississippi, Mississippi, 38677, USA
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Bury S, Kratochvíl L, Starostová Z. Scaling of erythrocyte shape and nucleus size among squamate reptiles: reanalysis points to constrained, proportional rather than adaptive changes. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221513. [PMID: 37122952 PMCID: PMC10130710 DOI: 10.1098/rsos.221513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 04/04/2023] [Indexed: 05/03/2023]
Abstract
Small erythrocytes might be beneficial for blood rheology, as they contribute less to blood viscosity than large erythrocytes. We predicted that rheological disadvantages of larger erythrocytes could be alleviated by relatively smaller nucleus size in larger cells allowing higher flexibility and by more elongated shape. Across squamate reptiles, we found that species with larger erythrocytes tend to have smaller ratio of nucleus size to cell size (N : C ratio), but that larger erythrocytes tend to be rounder, not more elongated. Nevertheless, we document that in fact nucleus area changes with erythrocyte area more or less linearly, which is also true for the relationship between cell length and cell width. These linear relationships suggest that nucleus size and cell size, and cell width and cell length, might be constrained to largely proportional mutual changes. The shifts in widely used N : C ratio and elongation ratio (cell length/cell width) with cell size might be misleading, as they do not reflect adaptive or maladaptive changes of erythrocytes, but rather mathematically trivial scaling of the ratios of two variables with a linear relationship with non-zero intercepts. We warn that ratio scaling without analyses of underlying patterns of evolutionary changes can lead to misinterpretation of evolutionary processes.
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Affiliation(s)
- Stanisław Bury
- Department of Comparative Anatomy, Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9, 30-387 Kraków, Poland
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czech Republic
| | - Zuzana Starostová
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 12844 Prague, Czech Republic
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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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Silva RM, Clemente FM, González-Fernández F, Nobari H, Haghighi H, Cancela Carral JM. Does maturity estimation, 2D:4D and training load measures explain physical fitness changes of youth football players? BMC Pediatr 2022; 22:726. [PMID: 36539728 PMCID: PMC9764734 DOI: 10.1186/s12887-022-03801-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVES The purpose of the present study was two-fold: (1) To analyse physical fitness changes of youth football players after a full-season; and (2) to examine whether physical fitness changes are explainable by estimated maturity status, 2digit:4digit ratio (2D:4D) from each hand and training load (TL) measures. METHODS Twenty-seven youth elite Under-15 football players were daily monitored for training load measures during 38 weeks. At the beginning and at the end of the season, all players were assessed for physical fitness. Also, the maturity status estimation and the length of the second and fourth digits of both hands were collected at the beginning of the season. RESULTS Significant differences were found for all physical fitness measures after the season. The second and fourth digits of left and right hands had negative moderate correlations with change of direction (COD) changes (r=-.39 to - 0.45 | p = .05 to 0.02). Also, the maturity offset measure had negative moderate correlations with COD changes (r=-.40 | p = .04). From the reported significant correlations, the maturity offset, Left 4D, Right 2D and Right 4D significantly predicted the Mod.505 COD test changes (β = 0.41, p = .04; β = -0.41, p = .04; β = -0.45, p = .02; and β = -0.44, p = .03, respectively). CONCLUSION The maturity offset and the 2D:4D measures have the potential to predict COD performance changes over-time in youth football players. Given the lack of associations between the maturity estimation, 2D:4D and training load measures, with the overall physical fitness measures, coaches should rely only at COD changes.
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Affiliation(s)
- Rui Miguel Silva
- Faculty of Educational Sciences and Sports Sciences, University of Vigo, 36005, Pontevedra, Spain
- Escola Superior Desporto e Lazer, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun'Álvares, 4900-347, Viana do Castelo, Portugal
- Research Center in Sports Performance, Recreation, Innovation and Technology - SPRINT, 4900-347, Viana do Castelo, Portugal
| | - Filipe Manuel Clemente
- Escola Superior Desporto e Lazer, Instituto Politécnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun'Álvares, 4900-347, Viana do Castelo, Portugal
- Research Center in Sports Performance, Recreation, Innovation and Technology - SPRINT, 4900-347, Viana do Castelo, Portugal
| | - Francisco González-Fernández
- Department of Physical Education and Sport, Faculty of Education and Sport Sciences, University of Granada, Campus Melilla, 52006, Melilla, Spain
- SER Research Group, Pontifical University of Comillas, 07013, Palma, Spain
| | - Hadi Nobari
- Faculty of Sport Sciences, University of Extremadura, 10003, Cáceres, Spain.
- Department of Exercise Physiology, Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabili, 56199-11367, Ardabil, Iran.
- Department of Motor Performance, Faculty of Physical Education and Mountain Sports, Transilvania University of Brasov, 500068, Brasov, Romania.
- Department of Sports Injuries and Corrective Exercises, Faculty of Sport Sciences, University of Isfahan, 81746-7344, Isfahan, Iran.
| | - Hamed Haghighi
- Department of Motor Performance, Faculty of Physical Education and Mountain Sports, Transilvania University of Brasov, 500068, Brasov, Romania
- Department of Sports Injuries and Corrective Exercises, Faculty of Sport Sciences, University of Isfahan, 81746-7344, Isfahan, Iran
| | - José Ma Cancela Carral
- Faculty of Educational Sciences and Sports Sciences, University of Vigo, 36005, Pontevedra, Spain
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Levin RN, Erickson-Schroth L, Mak K, Edmiston EK. Biological studies of transgender identity: A critical review. JOURNAL OF GAY & LESBIAN MENTAL HEALTH 2022. [DOI: 10.1080/19359705.2022.2127042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Rachel N. Levin
- Departments of Biology and Neuroscience, Pomona College, Claremont, CA, USA
| | | | - Kristie Mak
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - E. Kale Edmiston
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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The Percentage of Mature Height as a Morphometric Index of Somatic Growth: A Formal Scrutiny of Conventional Simple Ratio Scaling Assumptions. Pediatr Exerc Sci 2022; 35:107-115. [PMID: 36126945 DOI: 10.1123/pes.2022-0077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/21/2022] [Accepted: 07/29/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE To assess conventional assumptions that underpin the percentage of mature height index as the simple ratio of screening height (numerator) divided by actual or predicted adult height (denominator). METHODS We examined cross-sectional data from 99 academy youth soccer players (chronological age range, 11.5 to 17.7 y) skeletally immature at the screening time and with adult height measurements available at follow-up. RESULTS The y-intercept value of -60 cm (95% confidence interval, -115 to -6 cm) from linear regression between screening height and adult height indicated the failure to meet the zero y-intercept assumption. The correlation coefficient between present height and adult height of .64 (95% confidence interval, .50 to .74) was not equal to the ratio of coefficient of variations between these variables (CVx/CVy = 0.46) suggesting Tanner's special circumstance was violated. The non-zero correlation between the ratio and the denominator of .21 (95% confidence interval, .01 to .39) indicated that the percentage of mature height was biased low for players with generally shorter adult height, and vice versa. CONCLUSION For the first time, we have demonstrated that the percentage of mature height is an inconsistent statistic for determining the extent of completed growth, leading to potentially biased inferences for research and applied purposes.
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Banyeh M, Yeboah NA, Seidu L, Doglikuu AF. Sex estimation accuracies from variables of the index and ring fingers in a Ghanaian population: Absolute lengths versus length ratios. FORENSIC SCIENCE INTERNATIONAL: REPORTS 2022. [DOI: 10.1016/j.fsir.2022.100277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Abstract
Lukáš Kratochvíl and Michail Rovatsos respond to the recent study by Thibault Leroy and colleagues on island songbirds.
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Affiliation(s)
- Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague 12844, Czech Republic.
| | - Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, Prague 12844, Czech Republic
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Skorska MN, Coome LA, Peragine DE, Aitken M, VanderLaan DP. An anthropometric study of sexual orientation and gender identity in Thailand. Sci Rep 2021; 11:18432. [PMID: 34531440 PMCID: PMC8445993 DOI: 10.1038/s41598-021-97845-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 08/31/2021] [Indexed: 11/23/2022] Open
Abstract
The biodevelopment of psychological sex differentiation is putatively reflected in several anthropometrics. We examined eight anthropometrics in 1404 Thai participants varying in sex, sexual orientation, and gender identity/expression: heterosexual men and women, gay men, lesbian women, bisexual women, sao praphet song (transgender birth-assigned males), toms (transgender birth-assigned females), and dees (birth-assigned females attracted to toms). Exploratory factor analyses indicated the biomarkers should be analyzed independently. Using regressions, in birth-assigned males, less male-typical second-to-fourth digit ratios in the left hand were associated with sexual orientation towards men regardless of gender identity/expression, whereas shorter height and long-bone growth in the arms and legs were more evident among sao praphet song-who are both sexually oriented towards men and markedly feminine. In birth-assigned females, there were no clear sexual orientation effects, but there were possible gender-related effects. Groups of individuals who tend to be more masculine (i.e., toms, lesbians) showed more male-typical patterns on weight and leg length than some groups of individuals who tend to be less masculine (i.e., heterosexual women, dees). Thus, it appears the various anthropometrics inform separate biodevelopmental processes that differentially relate to sexual orientation and gender identity/expression depending on the measure in question as well as birth-assigned sex.
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Affiliation(s)
- Malvina N Skorska
- Child & Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, M6J 1H4, Canada
| | - Lindsay A Coome
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada
| | - Diana E Peragine
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada
| | - Madison Aitken
- Department of Psychiatry, University of Toronto, Toronto, ON, M5T 1R8, Canada
| | - Doug P VanderLaan
- Child & Youth Psychiatry, Centre for Addiction and Mental Health, Toronto, ON, M6J 1H4, Canada.
- Department of Psychology, University of Toronto Mississauga, 3359 Mississauga Rd. N., Mississauga, ON, L5L 1C6, Canada.
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Packard GC. When perception isn’t reality: allometric variation in the exaggerated mandibles of male stag beetles (Coleoptera: Lucanidae). Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
A variety of protocols have been used to study allometric variation in size of the exaggerated mandibles on male stag beetles. Many of these protocols entail logarithmic transformation of the original measurements followed by numerical analysis of the transformations by linear regression or some conceptual extension thereof. I reanalysed data from four such studies to show how these protocols can lead investigators to conclusions that are not well supported by the original observations. One of the data sets was originally reported to conform to simple loglinear allometry, with untransformed observations that presumably follow the path of a two-parameter power function; one was said to represent biphasic, loglinear allometry, with two distinctive morphs having different scaling relationships on the arithmetic scale; and two were originally described as cases of discontinuous, loglinear allometry caused by dimorphisms. My analyses, which were based on graphical analysis and nonlinear regression of untransformed observations, revealed that all the data sets form S-shaped distributions and that each of the distributions is well described by a four-parameter sigmoid function. None of the bivariate distributions reveals a discontinuity or dimorphism. Thus, the original authors unknowingly offered descriptions and interpretations for patterns of variation that do not exist in their data.
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Affiliation(s)
- Gary C Packard
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
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16
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Vorsatz M, Sanchez-Pages S, Turiegano E. Masculinity and Lying. Front Psychol 2021; 12:684226. [PMID: 34393911 PMCID: PMC8360853 DOI: 10.3389/fpsyg.2021.684226] [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: 03/23/2021] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Dishonesty in communication has important economic implications. The standing literature has shown that lying is less pervasive than predicted by standard economic theory. We explore whether biology can help to explain this behavior. In a sample of men, we study whether masculine traits are related to (dis)honesty in a sender-receiver game. We study three masculine physical traits: the second-to-fourth digit ratio, facial morphometric masculinity and the facial width-to-height ratio. These biomarkers display significant associations with lying and deception in the game. We also explore the extent to which these effects operate through social preferences or through beliefs about the behavior of receivers.
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Affiliation(s)
- Marc Vorsatz
- Department of Economic Analysis, National University of Distance Education (UNED), Madrid, Spain
| | | | - Enrique Turiegano
- Department of Biology, Autonomous University of Madrid, Madrid, Spain
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17
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Butovskaya M, Burkova V, Apalkova Y, Dronova D, Rostovtseva V, Karelin D, Mkrtchyan R, Negasheva M, Batsevich V. Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations. Sci Rep 2021; 11:8157. [PMID: 33854119 PMCID: PMC8046776 DOI: 10.1038/s41598-021-87394-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 03/25/2021] [Indexed: 02/06/2023] Open
Abstract
Recently, a number of authors have claimed that sexual dimorphism in the second-to-fourth digit ratio (2D:4D) is simply dependent on digit length and is an artifact of allometry. The goal of our study is to verify the validity of these assumptions. The study sample comprised 7,582 individuals (3,802 men and 3,780 women) from three large world populations: Europeans (n = 3043), East Africans (n = 2844), and Central Asians (n = 1695). The lengths of the second and fourth digits on both hands were measured. Digit ratios were computed according to standard procedures. Analyses were conducted separately for each hand for the whole sample and in succession for the three large populations. Additionally, we separately tested four age cohorts (≤ 13, 14-18, 19-30, and 31 ≥ years) to test the effect of developmental allometry. The second and fourth digits showed strong positive linear relationships on both hands, and demonstrated an increase with age; digit length in women from the youngest age cohort was longer or equal to that of men, and shorter than men in older age cohorts. However, the 2D:4D magnitude and its sexual dimorphism remained stable throughout the ontogeny. To test for an allometric effect on 2D:4D, the average digit lengths were calculated. Both sex and population origin were permanent reliable predictors of 2D:4D, whereas average digit length was not. Height was applied as another measure of allometric effect on the limited sample (≤ 30 years) from the European population, along with sex and age. No allometric effect was observed in this case. We conclude that sex differences in 2D:4D are not an artifact of allometry.
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Affiliation(s)
- Marina Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky pr., 32a, Moscow, Russia, 119991.
- National Research University Higher School of Economics, Moscow, Russia.
- Russian State University for the Humanities, Moscow, Russia.
| | - Valentina Burkova
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky pr., 32a, Moscow, Russia, 119991
- National Research University Higher School of Economics, Moscow, Russia
| | - Yulia Apalkova
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky pr., 32a, Moscow, Russia, 119991
| | - Daria Dronova
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky pr., 32a, Moscow, Russia, 119991
| | - Victoria Rostovtseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky pr., 32a, Moscow, Russia, 119991
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18
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Pruszkowska-Przybylska P, Sitek A, Rosset I, Sobalska-Kwapis M, Słomka M, Strapagiel D, Żądzińska E, Morling N. Associations between second to fourth digit ratio, cortisol, vitamin D, and body composition among Polish children. Sci Rep 2021; 11:7029. [PMID: 33782473 PMCID: PMC8007693 DOI: 10.1038/s41598-021-86521-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 03/16/2021] [Indexed: 01/17/2023] Open
Abstract
Associations between body characteristics (body composition: fat mass, muscle mass, cell, and water mass as well as body proportion—BMI), the 2D:4D digit ratio, and the concentrations of cortisol and vitamin (25-OH)D among Polish children have not been studied before. A total of 133 (73 girls and 60 boys) healthy Polish children aged 7–11 years were examined. The investigation was divided into three parts: measuring (the length of the second and fourth fingers in both hands, body composition, and body height and mass), questionnaires (socioeconomic status), and laboratory investigations (25-OH vitamin D and cortisol concentrations in saliva measured with ELISA methods). Boys with digit ratios below 1 had lower vitamin D concentration than those with digit ratios equal to or higher than 1 (Z = − 2.33; p = 0.019). Only boys with the male-typical pattern of 2D:4D digit ratio tended to have a lower 25-OH vitamin D concentration in saliva. Thus, it might indicate an effect of prenatal programming on the concentrations of steroid hormones in later life. Neither vitamin D, 2D:4D digit ratio nor the cortisol level was associated with the body components or proportions. More studies are needed to evaluate the molecular and genetic background of this phenomenon.
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Affiliation(s)
| | - Aneta Sitek
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237, Lodz, Poland
| | - Iwona Rosset
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237, Lodz, Poland
| | - Marta Sobalska-Kwapis
- The Biobank Lab, Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.,BBMRI.Pl Consortium, Wrocław, Poland
| | - Marcin Słomka
- The Biobank Lab, Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.,BBMRI.Pl Consortium, Wrocław, Poland
| | - Dominik Strapagiel
- The Biobank Lab, Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.,BBMRI.Pl Consortium, Wrocław, Poland
| | - Elżbieta Żądzińska
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Lodz, 90-237, Lodz, Poland.,Biological Anthropology and Comparative Anatomy Research Unit, School of Medicine, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Niels Morling
- Section of Forensic Genetics, Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V's Vej 11, 2100, Copenhagen, Denmark
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19
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Rodríguez-Ramos Á, Moriana JA, García-Torres F, Ruiz-Rubio M. Emotional stability is related to 2D:4D and social desirability in women: Possible implications on subjective well-being and psychopathology. PLoS One 2021; 16:e0248368. [PMID: 33690629 PMCID: PMC7942991 DOI: 10.1371/journal.pone.0248368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 02/23/2021] [Indexed: 01/07/2023] Open
Abstract
Emotional stability-Neuroticism is a complex construct influenced by genetics and environmental factors. Women tend to exhibit higher neuroticism scores than men, which may be associated with an increased risk of suffering from some common mental conditions. Some authors have pointed out the influence of sex hormones, since they induce sexual differentiation of the brain that can lead to sex-specific behaviors. 2D:4D digit ratio is commonly used as a marker of prenatal sex hormones. In this study we analyzed whether there was an association between 2D:4D and personality measured through the BFQ in a homogeneous sample of 101 young women college students. We found a positive association between 2D:4D and emotional stability, as well as with its subdimensions emotion control and impulse control. This association could be quadratic and nonlinear. However, no association was found with the other four dimensions. We also measured anxiety, depression and global life satisfaction, variables related to neuroticism. We observed that emotional stability is positively associated to social desirability and global life satisfaction, and negatively related to anxiety and depression. On the other hand, we did not find any association between 2D:4D and anxiety, depression, and global life satisfaction. These results can be linked to other aspects such as subjective well-being and psychopathological symptoms. This study may help to better understand how these constructs are related and could lead to future projects to elucidated how these variables influence personality.
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Affiliation(s)
- Ángel Rodríguez-Ramos
- Department of Genetics, University of Córdoba, Córdoba, Spain
- Department of Psychology, University of Córdoba, Córdoba, Spain
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), Córdoba, Spain
- University Hospital Reina Sofía of Córdoba, Córdoba, Spain
| | - Juan Antonio Moriana
- Department of Psychology, University of Córdoba, Córdoba, Spain
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), Córdoba, Spain
- University Hospital Reina Sofía of Córdoba, Córdoba, Spain
| | - Francisco García-Torres
- Department of Psychology, University of Córdoba, Córdoba, Spain
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), Córdoba, Spain
- University Hospital Reina Sofía of Córdoba, Córdoba, Spain
| | - Manuel Ruiz-Rubio
- Department of Genetics, University of Córdoba, Córdoba, Spain
- Maimónides Biomedical Research Institute of Córdoba (IMIBIC), Córdoba, Spain
- University Hospital Reina Sofía of Córdoba, Córdoba, Spain
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20
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Packard GC. Back to the basics: allometric growth by the horns of bovid mammals. ZOOLOGY 2020; 144:125878. [PMID: 33373943 DOI: 10.1016/j.zool.2020.125878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/14/2020] [Accepted: 11/10/2020] [Indexed: 11/26/2022]
Abstract
I used the equivalent of nonlinear analysis of covariance (ANCOVA) to re-examine relative growth by the horns on males and females of alpine ibex (Capra ibex) and mouflon sheep (Ovis gmelini). A prior study of allometric growth by the horns on these animals described a pattern of biphasic allometry for both sexes, with two different mathematical equations being required to capture the pattern of variation over the full range in body size. However, the investigation in question used conventional analytical methods based on logarithmic transformations, which alter bivariate distributions and commonly introduce problems with analysis and interpretation. My new analyses of data for both species revealed that untransformed observations for both males and females are monophasic and that they are described quite well by three-parameter power equations with negative intercepts. Equations for males follow a steep upward trajectory whereas those for females follow much shallower paths. The negative intercepts indicate that males and females of both species must attain a minimum body size before horns begin to develop. Conclusions from the earlier investigation were based on inaccurate perceptions of pattern in the data. Future studies should be based on graphical and analytical analysis of observations expressed on the original arithmetic scale.
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Affiliation(s)
- Gary C Packard
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
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21
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Rostovtseva VV, Mezentseva AA, Windhager S, Butovskaya ML. Second-to-fourth digit ratio and facial shape in Buryats of Southern Siberia. Early Hum Dev 2020; 149:105138. [PMID: 32750625 PMCID: PMC7374133 DOI: 10.1016/j.earlhumdev.2020.105138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/08/2020] [Accepted: 07/14/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND The 2nd-to-4th digit ratio (2D:4D) is a putative predictor of a prenatal exposure to sex hormones. 2D:4D is sexually dimorphic (males < females). Studies, linking digit ratio and full facial shapes among Europeans, show that a low 2D:4D is associated with a set of male-specific facial features. Buryats - Mongolian people from Southern Siberia - demonstrate a different pattern of facial sexual dimorphism than Europeans (narrower and more vertically elongated faces in men as opposed to women). AIM The aim of the present study was to investigate the association between facial shape and the 2D:4D in comparison to the pattern of facial sexual dimorphism in Buryats. SUBJECTS Buryats: 88 men and 80 women aged 20 ± 2 years. OUTCOME MEASURES To assess relationship between facial shape and 2D:4D we used a geometric morphometric approach based on standardized full-face frontal photographs and direct measurements of the digit lengths among right-handed individuals. RESULTS The results revealed that 2D:4D was associated with facial morphology in Buryat men, and to a lesser extent in women. Narrower faces, elongated in the vertical direction, and a narrower lower facial outline, were characteristic of Buryat men with low 2D:4D ratios, which corresponded to the male-like facial shapes in Buryats. CONCLUSIONS In Europeans, such facial features were reported for men with a high 2D:4D, which corresponded more to female-like European facial shapes. Hence, our results show that sex-specific morphogenesis in humans is multidirectional, and that digit ratio is capable of predicting sex-specific facial traits even in populations with differing sexually-dimorphic morphology.
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Affiliation(s)
- Victoria V. Rostovtseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninskiy pr-t 32a, Moscow 119334, Russia,Corresponding author
| | - Anna A. Mezentseva
- Department of Ethnology, Lomonosov Moscow State University, Lomonosovskiy pr-t 27/4, Moscow 119192, Russia
| | - Sonja Windhager
- Department of Evolutionary Anthropology, University of Vienna, Althanstrasse 14, Vienna 1090, Austria
| | - Marina L. Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninskiy pr-t 32a, Moscow 119334, Russia,National Research University Higher School of Economics, Myasnitskaya str. 20, Moscow 101000, Russia
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22
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Butovskaya M, Rostovtseva V, Butovskaya P, Burkova V, Dronova D, Filatova V, Sukhodolskaya E, Vasiliev V, Mesa T, Rosa A, Lazebny O. Oxytocin receptor gene polymorphism (rs53576) and digit ratio associates with aggression: comparison in seven ethnic groups. J Physiol Anthropol 2020; 39:20. [PMID: 32795360 PMCID: PMC7427763 DOI: 10.1186/s40101-020-00232-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/03/2020] [Indexed: 11/10/2022] Open
Abstract
Background The specific role of the oxytocin receptor (OXTR) gene polymorphisms in emotional support seeking, related to social norms and culturally normative behavior, has been discussed in several studies. Evidence on the association between aggression and OXTR polymorphisms has also been reported. The goal of the current study was to analyze the effect of the OXTR rs53576 polymorphism, prenatal testosterone effect (second-to-fourth digit ratio, or 2D:4D), and culture on aggression assessed with the Buss-Perry Aggression Questionnaire (BPAQ). Methods The data were collected in Russia and Tanzania and included seven ethnic groups of European, Asian, and African origin. The total sample included 1705 adults (837 males, 868 females). All the subjects were evaluated with the BPAQ. As a measure of prenatal androgenization, the second and fourth digits were measured directly from hand, and the digit ratios were calculated. All the participants provided buccal samples, from which genomic DNA was extracted, and the OXTR gene rs53576 polymorphism was genotyped. Statistical analysis was performed using SPSS version 23.0; the alpha level for all analyses was set at 0.05. Results The ethnic group factor was the most significant predictor of ratings on BPAQ (medium effect size for physical aggression, anger and hostility scales, and low for verbal aggression). To study the effect of sex, the OXTR polymorphism, and prenatal androgenization, we conducted the z-score transformation for BPAQ scales and 2D:4D for each ethnic group and pooled these data into new z-score variables. According to the GLM analysis after leveling the effects of culture (z-transformation), all four scales of BPAQ demonstrated association with sex (main effects), with men scoring higher on physical and verbal aggression and women scoring higher on anger and hostility. Anger and hostility scales were also associated with OXTR polymorphism and 2D:4D of the right hand. The lowest levels of anger and hostility were observed in individuals with the AA genotype, especially in men. Conclusions Our data suggest that both oxytocin (OXTR gene polymorphism) and fetal testosterone (2D:4D) may significantly affect emotional (anger) and cognitive (hostility) aggression in humans, given the leveling the role of culture.
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Affiliation(s)
- Marina Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky Prospect 32a, 119991, Moscow, Russia. .,National Research University Higher School of Economics, Moscow, Russia.
| | - Victoria Rostovtseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky Prospect 32a, 119991, Moscow, Russia
| | | | - Valentina Burkova
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky Prospect 32a, 119991, Moscow, Russia.,National Research University Higher School of Economics, Moscow, Russia
| | - Daria Dronova
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky Prospect 32a, 119991, Moscow, Russia
| | - Vasilisa Filatova
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninsky Prospect 32a, 119991, Moscow, Russia
| | - Eugenia Sukhodolskaya
- Federal Budget Institution of Science "Central Research Institute of Epidemiology" of The Federal Service on Customers' Rights Protection and Human Well-being Surveillance, Moscow, Russia
| | - Vasiliy Vasiliev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Tania Mesa
- Secció de Zoologia i Antropologia Biològica, Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona, Spain
| | - Araceli Rosa
- Secció de Zoologia i Antropologia Biològica, Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona, Spain.,Institut de Biomedicina de la Universitat de Barcelona (IBUB), Barcelona, Spain.,Centre for Biomedical Research Network on Mental Health (CIBERSAM), Instituto de Salud Carlos III, Barcelona, Spain
| | - Oleg Lazebny
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
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23
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Kowal M, Sorokowski P, Żelaźniewicz A, Nowak J, Orzechowski S, Żurek G, Żurek A, Juszkiewicz A, Wojtycka L, Sieniuć W, Poniatowska M, Tarnowska K, Kowalska K, Drabik K, Łukaszek P, Krawczyk K, Stefaniak T, Danek N. No relationship between the digit ratios (2D:4D) and salivary testosterone change: Study on men under an acute exercise. Sci Rep 2020; 10:10068. [PMID: 32572079 PMCID: PMC7308391 DOI: 10.1038/s41598-020-66915-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/16/2020] [Indexed: 01/08/2023] Open
Abstract
The digit ratio (2D:4D) is said to be a potential marker of exposure to prenatal sex steroids. Some studies suggest that the 2D:4D is also linked with the testosterone response to challenging situations due to organizational effect of prenatal hormonal milieu on adult endocrine functioning. However, up to date, there were only four studies (conducted on small samples) that examined the 2D:4D and the testosterone response to a challenging situation (i.e. physical exertion or aggressive context). Here, we examined the relationship between the 2D:4D and the testosterone change under an acute exercise among 97 men. We found that the digit ratios (the right 2D:4D, the left 2D:4D, and the right minus left 2D:4D) were neither predictors of pre-exercise testosterone, nor the change in testosterone level after a cycling task. Our results add a contradictory to previous studies evidence in a discussion on the links of the 2D:4D and the testosterone change.
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Affiliation(s)
- Marta Kowal
- Institute of Psychology, University of Wrocław, Wrocław, Poland
| | - Piotr Sorokowski
- Institute of Psychology, University of Wrocław, Wrocław, Poland.
| | | | - Judyta Nowak
- Department of Human Biology, University of Wrocław, Wrocław, Poland
| | | | - Grzegorz Żurek
- University School of Physical Education in Wrocław, Wrocław, Poland
| | - Alina Żurek
- Institute of Psychology, University of Wrocław, Wrocław, Poland
| | | | - Lidia Wojtycka
- Institute of Psychology, University of Wrocław, Wrocław, Poland
| | | | | | | | - Kaja Kowalska
- Institute of Psychology, University of Wrocław, Wrocław, Poland
| | | | | | | | | | - Natalia Danek
- University School of Physical Education in Wrocław, Wrocław, Poland
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24
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Lombardo MP, Otieno S. The associations between digit ratio, aerobic fitness, physical skills, and overall physical fitness of elite youth distance runners. Am J Hum Biol 2020; 33:e23448. [PMID: 32501636 DOI: 10.1002/ajhb.23448] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 04/23/2020] [Accepted: 05/13/2020] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE Lower digit ratios between the lengths of fingers 2 (2D) and 4 (4D) (2D:4D) are associated with superior distance running and athletic performance. We examined relationships between 2D:4D, aerobic fitness, physical skills, and overall physical fitness of elite adolescent boy and girl distance runners. METHODS Subjects were top five finishers for their sex and age in 10 or more races of 10 km or longer in Michigan in 1981. We calculated 2D:4D of 15 girls and 11 boys from radiographs. Subject peak O2 consumption (VO2Peak ), ventilatory threshold (VT), and point of equivalent change (PEC) were collected during intermittent treadmill protocol tests. Performances on physical skills tests (flex-arm hang, broad jump, vertical jump, figure-8-run, sit ups, and sit-and-reach test) were collected in the laboratory. We examined the interrelationships between 2D:4D, subject sex, aerobic fitness, physical skills test performance, and overall physical fitness, a composite of aerobic and physical skills performance with correlation, linear regression, t tests, and principle component analyses. RESULTS Girls had significantly larger right hand (R) 2D:4D than boys. Boys had greater VO2Peak by mass than girls. Boys with lower R2D:4D had significantly greater VO2Peak and PEC. Girls with lower R2D:4D had significantly greater VT. Factors associated with aerobic fitness explained most of the variation in composite physical fitness scores. Composite aerobic fitness, physical skills, and overall physical fitness scores of boys were negatively correlated with R2D:4D. CONCLUSIONS These data suggest that R2D:4D may help predict distance running performance in girls and boys and overall physical fitness in boys and provide additional insights into the innate factors influencing youth physical fitness.
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Affiliation(s)
- Michael P Lombardo
- Biology Department, Grand Valley State University, Allendale, Michigan, USA
| | - Sango Otieno
- Statistics Department, Grand Valley State University, Allendale, Michigan, USA
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25
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Sartori C, Gianesella M, Pilastro A, Mantovani R, Armato L, Fiore E. Digit ratio and length asymmetry in calves' limbs. ZOOLOGY 2020; 140:125777. [PMID: 32248058 DOI: 10.1016/j.zool.2020.125777] [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: 08/07/2019] [Revised: 02/16/2020] [Accepted: 02/17/2020] [Indexed: 10/24/2022]
Abstract
This study considered possible sexual dimorphism in the relative lengths of the second, third and fourth digits (digit ratio), in calves. Furthermore, a different length of the bone structures of the third (3D) and of the fourth (4D) digits has been examined as an evolutionary adaptation to locomotion on soft ground. The length of the digital bones of the right fore-limb of 33 females and 15 male calves was measured in vivo using a portable X-ray machine. The vestigial structure of the second digit (2D), and 3D and 4D, from metacarpus to the third phalanx were considered in a mixed model, as well as some ratios between 2D and different parts of 3D or 4D (2D:3D and 2D:4D). A covariate for the mean finger length was considered for digit ratios to control for possible biases due to shape allometry. Shorter first phalanx and trotter were found in 3D than in 4D, and the reverse for the third phalanx. The 2D was significantly shorter in females, as well as the second phalanges of 3D and 4D. Significant sex differences in 2D:3D and 2D:4D were found for some digit parts of 3D and 4D and for the first phalanges of 3D:4D. These ratios were always shorter in females, in contrast to that found in most mammals. The asymmetry between 3D and 4D could mean a functional adaptation for locomotion. Sex differences in 2D:4D and 3D:4D were found, but with a reverse pattern than in most mammal species (males > females rather than males < females). In this regard digit ratio in calves was similar to that of Old World monkeys. This study is the first investigation of digit ratio in Ungulates, whose limbs differ from the limbs of most mammals, maintaining five digits. The reverse pattern of sex differences (digit ratios: males> females) could be due to the peculiar nature of the vestigial dewclaw of 2D and to the hormone patterns acting on this digit during development, but further research is required around this topic.
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Affiliation(s)
- Cristina Sartori
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Viale dell'Università 16, 35020, Legnaro, Padova, Italy.
| | - Matteo Gianesella
- Department of Animal Medicine, Productions and Health (MAPS), University of Padova, Padova, Italy
| | | | - Roberto Mantovani
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Viale dell'Università 16, 35020, Legnaro, Padova, Italy
| | - Leonardo Armato
- Department of Animal Medicine, Productions and Health (MAPS), University of Padova, Padova, Italy
| | - Enrico Fiore
- Department of Animal Medicine, Productions and Health (MAPS), University of Padova, Padova, Italy
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Stibbard-Hawkes DNE. No Association between 2D:4D Ratio and Hunting Success among Hadza Hunters. HUMAN NATURE (HAWTHORNE, N.Y.) 2020; 31:22-42. [PMID: 31838723 DOI: 10.1007/s12110-019-09359-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ratio of index- and ring-finger lengths (2D:4D ratio) is thought to be related to prenatal androgen exposure, and in many, though not all, populations, men have a lower average digit ratio than do women. In many studies an inverse relationship has been observed, among both men and women, between 2D:4D ratio and measures of athletic ability. It has been further suggested that, in hunter-gatherer populations, 2D:4D ratio might also be negatively correlated with hunting ability, itself assumed to be contingent on athleticism. This hypothesis has been tested using endurance running performance among runners from a Western, educated, and industrialized population as a proximate measure of hunting ability. However, it has not previously been tested among actual hunter-gatherers using more ecologically valid measures of hunting ability and success. The current study addresses this question among Tanzanian Hadza hunter-gatherers. I employ a novel method of assessing hunting reputation that, unlike previous methods, allows granular distinctions to be made between hunters at all levels of perceived ability. I find no statistically significant relationship between digit ratio and either hunting reputation or two important hunting skills. I confirm that Hadza men have higher mean 2D:4D ratios than men in many Western populations. I discuss the notion that 2D:4D ratio may be the consequence of an allometric scaling relationship between relative and absolute finger lengths. Although it is difficult to draw clear conclusions from these results, the current study provides no support for the theorized relationship between 2D:4D ratio and hunting skill.
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Manning JT, Fink B. Sexual dimorphism in the ontogeny of second (2D) and fourth (4D) digit lengths, and digit ratio (2D:4D). Am J Hum Biol 2019; 30:e23138. [PMID: 30133905 DOI: 10.1002/ajhb.23138] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 04/29/2018] [Accepted: 05/10/2018] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE Sex differences are often reported in digit lengths and digit ratio (2D:4D). However, the ontogeny of these sex differences and their interrelationships are less well known. METHODS We considered sex differences in the lengths of the 2nd (2D) and 4th (4D) digit and 2D:4D in children aged 2 to 18 years (Sample I, n = 680) and adults aged 18 to 30 years (Sample II, n = 89,246). Digit length was determined by direct experimenter-measurement (Sample I) and direct self-measurement (Sample II). The data were tested with two-factor ANOVA's (sex and year-group). RESULTS In both samples, there were significant main effects of sex and year-group, and a significant interaction effect on digit length. Digit length was positively related to age in both samples. Boys had longer digits than girls but only after 13 years. Men had longer digits than women and the dimorphism increased from 18 to 30 years. There were significant sex differences in 2D:4D (males < females), but no significant effect of age and no interaction effect of age and sex on 2D:4D in children or adults. CONCLUSIONS Between 2 and 30 years, the lengths and the sexual dimorphisms of 2D and 4D are dependent on age. In contrast, 2D:4D is not age-dependent. We discuss our findings in the context of the ontogeny of digits and in the light of recent claims on the presence of static allometry in 2D and 4D lengths.
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Affiliation(s)
- John T Manning
- Applied Sports, Technology, Exercise, and Medicine (A-STEM), Swansea University, Swansea, United Kingdom, University of Swansea
| | - Bernhard Fink
- Department of Behavioral Ecology, University of Goettingen, Germany.,Hanse-Wissenschaftskolleg, Institute for Advanced Study, Delmenhorst, Germany
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Misiak M, Butovskaya M, Oleszkiewicz A, Sorokowski P. Digit ratio and hand grip strength are associated with male competition outcomes: A study among traditional populations of the Yali and Hadza. Am J Hum Biol 2019; 32:e23321. [PMID: 31512345 DOI: 10.1002/ajhb.23321] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 08/17/2019] [Accepted: 08/28/2019] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES Indirect measures of physiological features, such as digit ratio and hand grip strength (HGS), are associated with the outcome of male competition activities. However, most of the studies were conducted in developed and industrialized societies. We tested the hypothesis that both digit ratio and HGS are associated with performance in male-specific activities in two traditional preindustrial societies: Yali and Hadza. METHODS To measure masculine behavioral traits, we determined warriorship status (Yali; n = 49) and assessed hunting skills (Yali n = 47 and Hadza n = 49). We also assessed the digit ratio and HGS of each male. We conducted our analyses using the Bayesian approach. RESULTS Bayesian regression models indicated that greater hand grip strength is associated with better hunting outcomes among Hadza males. We did not find a similar link for the Yali. We found anecdotal evidence for the link between left hand digit ratio and the number of birds hunted by Hadza. We found no evidence for the link between digit ratio and performance in male-male competition. CONCLUSIONS Our results suggest that male-male competition outcomes are determined by upper body strength, but only in the Hadza population. We also found limited support for the hypothesis that digit ratio is associated with hunting success among the Hadza. We found no support for the hypothesis concerning the digit ratio or HGS among the Yali. Our research provides partial support for the evolutionary hypotheses based on studies conducted in industrialized populations.
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Affiliation(s)
- Michał Misiak
- Faculty of Historical and Pedagogical Sciences, Institute of Psychology, University of Wroclaw, Wroclaw, Poland
| | - Marina Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russia
| | - Anna Oleszkiewicz
- Faculty of Historical and Pedagogical Sciences, Institute of Psychology, University of Wroclaw, Wroclaw, Poland.,Department of Otorhinolaryngology, Smell and Taste Clinic, Dresden, Germany
| | - Piotr Sorokowski
- Faculty of Historical and Pedagogical Sciences, Institute of Psychology, University of Wroclaw, Wroclaw, Poland
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Blomquist GE. Unpacking the heritability of body mass index and other ratios. Am J Hum Biol 2019; 31:e23289. [PMID: 31243841 DOI: 10.1002/ajhb.23289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 04/20/2019] [Accepted: 06/09/2019] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVES Ratios of weight to height, especially body mass index (BMI = kg/m2 ), are often used in epidemiological and genetic studies of health, but the limitations of quantitative genetic analysis of ratios are not widely known. The heritability of these ratios can be closely approximated from a bivariate quantitative genetic model of weight and height which clarifies how BMI heritabilities change. METHODS I explored this bivariate approximation and alternative measures through simulated datasets fit with linear mixed models. Simulated data were based on published heritabilities and other statistics for BMI and related anthropometric dimensions from four human samples. RESULTS Inspection of the bivariate approximation and analysis of simulated data show the heritability of weight/height crucially depends on the phenotypic (rP ) and genetic correlations (rA ) between weight and height. Changes in these correlations can have dramatic effects on the heritability of BMI. For example, when rP ≪ rA heritability of BMI is reduced to 35-50% of its value when the correlations are equal. DISCUSSION Increasing adiposity likely decreases the phenotypic correlations more than the genetic correlation resulting in reduced heritability of the ratio. This contrasts with the commonly reported stability or increase of BMI heritability and implies it may result from increased genetic variance in weight in obesogenic environments. The bivariate model offers other advantages over ratios, including estimating the conditional genetic variance or heritability of weight that is unassociated with height, which may prove useful in quantitative and molecular genetic studies.
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Lombardo MP, Otieno S, Heiss A. College-aged women in the United States that play overhand throwing sports have masculine digit ratios. PLoS One 2018; 13:e0203685. [PMID: 30212523 PMCID: PMC6136748 DOI: 10.1371/journal.pone.0203685] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 08/24/2018] [Indexed: 11/19/2022] Open
Abstract
Athletic prowess in both males and females is negatively correlated with the ratio between the lengths of the second and fourth fingers (2D:4D), a correlate of prenatal testosterone exposure. Because multiple lines of evidence suggest that prenatal testosterone exposure is associated with sports interest, motivation, and athletic performance we measured the digit ratios of 77 non-athletes, 103 varsity athletes, and 78 club sport athletes to test 8 hypotheses about the relationship between digit ratio and the athletic behavior of college-age women in the USA. Using independent samples t-tests, we found no significant differences between the digit ratios of women that (1) were athletes and non-athletes, (2) were varsity or club sport athletes, (3) had played or were currently playing individual or team sports, (4) played contact and non-contact sports, (5) played sports involving a ball and those that do not, (6) played sports where the outcome was determined by a score or the outcome of direct physical competition or subjectively by judges, or (7) were starters or reserves on their teams. However, women that played overhand throwing sports softball and water polo had significantly smaller digit ratios than did women that played other sports. These differences were not due to scaling effects. The independent samples t-test results were supported by subsequent Monte Carlo bootstrap, Bayesian, Random Forest, and multiple linear regression analyses. We suggest that the organizational consequences of prenatal testosterone exposure may influence the anatomy and physiology of women that leads to success playing overhand throwing sports.
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Affiliation(s)
- Michael P. Lombardo
- Biology Department, Grand Valley State University, Allendale, Michigan, United States of America
- * E-mail:
| | - Sango Otieno
- Statistics Department, Grand Valley State University, Allendale, Michigan, United States of America
| | - Adam Heiss
- Statistics Department, Grand Valley State University, Allendale, Michigan, United States of America
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Packard GC. Evolutionary allometry of horn length in the mammalian family Bovidae reconciled by non-linear regression. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Gary C Packard
- Department of Biology, Colorado State University, Fort Collins, CO, USA
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Li G, Lv X, Zhou J, Shen C, Xia D, Xie H, Luo Y. Are the surface areas of the gills and body involved with changing metabolic scaling with temperature? ACTA ACUST UNITED AC 2018; 221:jeb.174474. [PMID: 29559548 DOI: 10.1242/jeb.174474] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 03/13/2018] [Indexed: 01/04/2023]
Abstract
The metabolic-level boundaries (MLB) hypothesis proposes that metabolic level mediates the relative influence of surface area (SA)- versus volume-related metabolic processes on the body-mass scaling of metabolic rate in organisms. The variation in the scaling of SA may affect how metabolic level affects the metabolic scaling exponent. This study aimed to determine the influence of increasing metabolic level at a higher temperature on the metabolic scaling exponent of the goldfish and determine the link between metabolic scaling exponents and SA parameters of both gills and body. The SA of gills and body and the resting metabolic rate (RMR) of the goldfish were assessed at 15°C and 25°C, and their mass scaling exponents were analyzed. The results showed a significantly higher RMR, with a lower scaling exponent, in the goldfish at a higher temperature. The SA of the gills and the total SA of the fish (TSA) were reduced with the increasing temperature. The scaling exponent of RMR (bRMR) tended to be close to that of the TSA at a higher temperature. This suggests that temperature positively affects metabolic level but negatively affects bRMR The findings support the MLB hypothesis. The lower scaling exponent at a higher temperature can be alternatively explained as follows: the higher viscosity of cold water impedes respiratory ventilation and oxygen uptake and reduces metabolic rate more in smaller individuals than in larger individuals at lower temperature, thus resulting in a negative association between temperature and bRMR.
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Affiliation(s)
- Ge Li
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China.,Wudu Bayi High School, Wudu, Longnan, Gansu 746000, China
| | - Xiao Lv
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Jing Zhou
- Department of Clinical Medicine, Chongqing Medical and Pharmaceutical College, Chongqing 401331, China
| | - Cong Shen
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Danyang Xia
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Hang Xie
- Luzhou Agricultural Bureau, National Nature Reserve of Rare and Endemic Fish in the Upper Yangtze River for Luzhou Workstation, Luzhou, Sichuan 646009, China
| | - Yiping Luo
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400715, China
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Packard GC. A new research paradigm for bivariate allometry: combining ANOVA and non-linear regression. J Exp Biol 2018; 221:221/7/jeb177519. [DOI: 10.1242/jeb.177519] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 02/26/2018] [Indexed: 11/20/2022]
Abstract
ABSTRACT
A novel statistical routine is presented here for exploring and comparing patterns of allometric variation in two or more groups of subjects. The routine combines elements of the analysis of variance (ANOVA) with non-linear regression to achieve the equivalent of an analysis of covariance (ANCOVA) on curvilinear data. The starting point is a three-parameter power equation to which a categorical variable has been added to identify membership by each subject in a specific group or treatment. The protocol differs from earlier ones in that different assumptions can be made about the form for random error in the full statistical model (i.e. normal and homoscedastic, normal and heteroscedastic, lognormal and heteroscedastic). The general equation and several modifications thereof were used to study allometric variation in field metabolic rates of marsupial and placental mammals. The allometric equations for both marsupials and placentals have an explicit, non-zero intercept, but the allometric exponent is higher in the equation for placentals than in that for marsupials. The approach followed here is extraordinarily versatile, and it has wider application in allometry than standard ANCOVA performed on logarithmic transformations.
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Affiliation(s)
- Gary C. Packard
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
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Lolli L, Batterham AM, Atkinson G. Correct allometric analysis is always helpful for scaling flow-mediated dilation in research and individual patient contexts. Clin Physiol Funct Imaging 2017; 38:907-910. [PMID: 29114983 DOI: 10.1111/cpf.12486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 10/11/2017] [Indexed: 11/28/2022]
Abstract
McLay et al. (Clin Physiol Funct Imaging (2017); DOI: 10.1111/cpf.12465) recently examined whether the allometric scaling of flow-mediated dilation influenced the mean difference between samples of young and older adults compared with the traditional percentage change approach. They also explored whether a new scaling calculation improved the ability to obtain individually scaled flow-mediated dilation. In our response to their study, we can demonstrate that McLay et al. (Clin Physiol Funct Imaging, 2017) have (i) managed to formulate a new scaling index which does nothing to remove the dependency of that index on baseline diameter and (ii) suggested, incorrectly, that the original allometric approach cannot be used to derive individually-adjusted values of flow-mediated dilation, which can be interpreted in a similar way to a percentage change.
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Affiliation(s)
- Lorenzo Lolli
- Health and Social Care Institute, Teesside University, Middlesbrough, UK
| | - Alan M Batterham
- Health and Social Care Institute, Teesside University, Middlesbrough, UK
| | - Greg Atkinson
- Health and Social Care Institute, Teesside University, Middlesbrough, UK
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