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Ribeiro E, Neave N, Marsili BK, Figueiredo ECG, Martino-Andrade AJ, de Moraes RN. Prenatal androgenization (2D:4D) predictions of tennis match-play success in junior players: A search for physiological explanations. Am J Hum Biol 2024; 36:e23979. [PMID: 37602536 DOI: 10.1002/ajhb.23979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023] Open
Abstract
AIM This study aims to investigate the possible association between digit ratio (2D:4D) and match-play success (MPS) in junior tennis players. In addition, we consider the possible explanatory pathways of these associations in relation to psychological, strength, power, and hormonal parameters. METHODS We performed a cross-sectional study, with a sample comprised of 64 male junior tennis players (11-18 years old). Digit ratio was calculated from direct finger measurements. In addition, we measured the ratio of wins by number of matches played in 5 years of official competition (MPS), handgrip strength (HGS), standing long jump (SLJ), training (in weekly hours), and expertise (number of years in official competition). Salivary testosterone and cortisol levels were measured before and after physical "challenge" tests. RESULTS The 2D:4D correlated negatively with HGS and SLJ. MPS was also negatively associated with 2D:4D, but was positively correlated to HGS, expertise, training, and self-confidence (SC). Multiple linear regression showed 2D:4D and expertise were associated with MPS (43%-54%). None of the physical, or hormonal variables tested explained the links between 2D:4D and MPS. CONCLUSION Therefore, the specific fitness components influenced by prenatal androgenization that moderate sports success remain unknown. Future studies should explore the interaction of 2D:4D, with tennis exercises as a challenge to induce hormonal change, the effect of pubertal stage, and the influence of aerobic endurance in determining MPS.
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Affiliation(s)
- Evaldo Ribeiro
- Litoral Sector, Federal University of Paraná, Matinhos, Brazil
- Department of Physiology, Federal University of Paraná, Curitiba, Brazil
| | - Nick Neave
- Department of Psychology, Northumbria University, Newcastle-upon-Tyne, UK
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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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Anthropometrics, Performance, and Psychological Outcomes in Mixed Martial Arts Athletes. BIOLOGY 2022; 11:biology11081147. [PMID: 36009774 PMCID: PMC9404939 DOI: 10.3390/biology11081147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/27/2022] [Accepted: 05/28/2022] [Indexed: 11/17/2022]
Abstract
The digit ratio (2D:4D) is related to prenatal testosterone (T) and sports performance. Few investigations have explored 2D:4D in determining the potential performance of individuals in power-based sports, specifically combat sports. This study compared 2D:4D between mixed martial arts (MMA) athletes and non-athletes and investigated the association between (1) handgrip strength (HGS) and lean body mass (LBM) with 2D:4D in MMA athletes and (2) psychometric variables and 2D:4D in MMA athletes and non-athletes. In total, 122 men participated in this study (53 non-athletes, 45 professionals, and 24 amateur fighters). The 2D:4D was measured using a caliper, HGS was assessed with a dynamometer, and psychometric variables were evaluated using questionnaires. Athletes displayed significantly (p < 0.05) lower median values of right (0.95 ± 0.04) and left (0.96 ± 0.03) 2D:4D in comparison with non-athletes, (0.97 ± 0.03) and (0.99 ± 0.03), respectively. We observed that left hand 2D:4D was negatively correlated with HGS (r = −0.43; p < 0.05) and lean body mass (r = −0.49; p < 0.05) in professional athletes. Professional athletes also displayed significant differences (* p < 0.05; ** p < 0.001) in psychometric variables compared to non-athletes for (1) agreeableness **, median values (interquartile range) = −0.11 (−0.19−0.07) and 0.2 (−0.09−0.33), respectively; (2) anger **, mean ± standard error = 2.40 ± 0.12 and 2.89 ± 0.89, respectively; and (3) openness *, mean ± standard error = 0.17 ± 0.04 and −0.006 ± 0.04, respectively. However, we did not observe an association between psychometric variables or wins with 2D:4D. In conjunction with other measures, 2D:4D is valuable in determining the potential athleticism of an MMA athlete.
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Bäck N, Schaefer K, Windhager S. Handgrip strength and 2D : 4D in women: homogeneous samples challenge the (apparent) gender paradox. Proc Biol Sci 2021; 288:20212328. [PMID: 34875193 PMCID: PMC8651413 DOI: 10.1098/rspb.2021.2328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The length ratio between the second and the fourth digit (2D : 4D) is a retrospective, non-invasive biomarker for prenatal androgen exposure. It was found to be negatively correlated with handgrip strength (HGS) in men, but the evidence for women is mixed. Such studies in women call for increased detection sensitivity. The present study was designed to reduce potential confounding factors, especially age and ethnicity variation. We measured the digit ratios and HGS of 125 healthy women between 19 and 31 years of age from a remote region in Austria. 2D : 4D of both hands was significantly and negatively correlated with HGS (n = 125, right hand: r = -0.255, p = 0.002, left hand: r = -0.206, p = 0.011). Size, direction and significance of correlation coefficients remained stable when statistically controlling for age, body weight, body height, body mass index or hours of exercise per week. This yields theory-consistent evidence that HGS and 2D : 4D are clearly associated in women-when sufficiently reducing genetic variation (confounding 2D : 4D), the ontogenetic environment and age ranges (confounding HGS) in the study population. This finding implies similar organizing effects of prenatal androgens as in men, pointing to a more parsimonious developmental mechanism and a new look into its proximate and ultimate causes.
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Affiliation(s)
- Nora Bäck
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Katrin Schaefer
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria.,Human Evolution and Archaeological Sciences (HEAS), University of Vienna, Vienna, Austria
| | - Sonja Windhager
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
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Pasanen BE, Tomkinson JM, Dufner TJ, Park CW, Fitzgerald JS, Tomkinson GR. The relationship between digit ratio (2D:4D) and muscular fitness: A systematic review and meta-analysis. Am J Hum Biol 2021; 34:e23657. [PMID: 34331730 DOI: 10.1002/ajhb.23657] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/18/2021] [Accepted: 07/20/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Digit ratio (2D:4D), a marker of prenatal testosterone exposure, is a weak negative correlate of sports/athletic/fitness performance. While numerous studies have examined the relationship between 2D:4D and physical fitness, there has never been a comprehensive study that has synthesized studies examining relationships between 2D:4D and muscular fitness. OBJECTIVES To systematically review and meta-analyze the relationship between 2D:4D and muscular fitness measured as handgrip strength (HGS). METHODS We systematically searched five electronic databases, reference lists, topical systematic reviews/meta-analyses, and personal libraries in November 2020. Peer-reviewed, cross-sectional studies that reported Pearson's correlation coefficients between objectively measured 2D:4D and HGS were included. We used random-effects meta-analysis to estimate the pooled correlation and the 95% confidence interval (95%CI), and moderator analyses to estimate the influence of sex and age. RESULTS Data from 22 studies, representing 5271 individuals from 11 countries ranging in (mean) age from 10.4 to 58.0 years, were included. Overall, there was a weak negative correlation between 2D:4D and HGS (r = -0.15, 95%CI = -0.20 to -0.09), indicating that individuals with low 2D:4Ds had high HGS. We found substantial heterogeneity between studies (Q = 123.4, p < .0001; I2 = 74%), but neither sex (Q = 0.003, p = .96) nor age (Q = 0.46, p = .50) significantly moderated the pooled correlation. CONCLUSIONS We found a weak negative relationship between 2D:4D and HGS, which showed substantial heterogeneity between studies, but was neither moderated by sex nor age. Our finding probably reflects both the long-term (organizational) and short-term (activational) benefits of testosterone.
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Affiliation(s)
- Brooke E Pasanen
- Department of Education, Health and Behavior Studies, University of North Dakota, Grand Forks, North Dakota, USA
| | - Jordan M Tomkinson
- Department of Education, Health and Behavior Studies, University of North Dakota, Grand Forks, North Dakota, USA
| | - Trevor J Dufner
- Department of Education, Health and Behavior Studies, University of North Dakota, Grand Forks, North Dakota, USA
| | - Chan Woong Park
- Department of Education, Health and Behavior Studies, University of North Dakota, Grand Forks, North Dakota, USA
| | - John S Fitzgerald
- Department of Education, Health and Behavior Studies, University of North Dakota, Grand Forks, North Dakota, USA
| | - Grant R Tomkinson
- Department of Education, Health and Behavior Studies, University of North Dakota, Grand Forks, North Dakota, USA.,Alliance for Research in Exercise, Nutrition and Activity (ARENA), Allied Health and Human Performance, University of South Australia, Adelaide, South Australia, Australia
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Zhang K, Yang X, Zhang M, Wang C, Fang P, Xue M, Zhao J, Gao X, Pan R, Gong P. Revisiting the relationships of 2D:4D with androgen receptor (AR) gene and current testosterone levels: Replication study and meta-analyses. J Neurosci Res 2019; 98:353-370. [PMID: 31359506 DOI: 10.1002/jnr.24502] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 07/13/2019] [Accepted: 07/15/2019] [Indexed: 01/07/2023]
Abstract
The relationships of digit ratio (2D:4D) with the length of AR (CAG)n, and testosterone levels from saliva and blood have been extensively debated over the years. This research including three studies further clarifies such controversies. To do so, we re-examined the relationships between the length of AR (CAG)n, 2D:4D, and current testosterone levels, through replication study and meta-analysis for each study. The results indicate: (a) the length of AR (CAG)n is not significantly associated with 2D:4D; (b) current testosterone levels are not significantly associated with the ratio; and (c) the length is not significantly associated with testosterone levels. Thus, AR (CAG)n and current testosterone levels are not significantly related to 2D:4D at individual level.
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Affiliation(s)
- Kejin Zhang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, China.,College of Life Science, Northwest University, Xi'an, China
| | - Xing Yang
- College of Life Science, Northwest University, Xi'an, China
| | - Mengfei Zhang
- College of Life Science, Northwest University, Xi'an, China
| | - Chunlan Wang
- College of Life Science, Northwest University, Xi'an, China
| | - Pengpeng Fang
- College of Life Science, Northwest University, Xi'an, China
| | - Mengying Xue
- College of Life Science, Northwest University, Xi'an, China
| | - Jing Zhao
- College of Life Science, Northwest University, Xi'an, China
| | - Xiaocai Gao
- Institute of Population and Health, Northwest University, Xi'an, China
| | - Ruliang Pan
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, China.,School of Human Sciences, Centre for Evolutionary Biology, The University of Western Australia, Perth, WA, Australia.,School of Biological Sciences, The University of Western Australia, Perth, WA, Australia
| | - Pingyuan Gong
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, China.,College of Life Science, Northwest University, Xi'an, China.,Institute of Population and Health, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China
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Králík M, Hupková A, Zeman T, Hložek M, Hlaváček L, Slováčková M, Čuta M, Urbanová P. Family effects on the digit ratio (2D:4D): The role of the interbirth interval. Am J Hum Biol 2019; 31:e23260. [PMID: 31183942 DOI: 10.1002/ajhb.23260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/26/2019] [Accepted: 05/12/2019] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVES Family represents the closest social environment that immediately affects human ontogeny from an early prenatal period. This study aimed to assess sibship influences on the second-to-fourth digit length ratio (2D:4D ratio). METHODS The source sample represented 329 children aged 6.5 to 15.8 years (Czech Republic), including a subsample of 75 sibling pairs. A combination of (a) between-family design (cross-sectional sample) and (b) within-family design (pairs of siblings) was used to study the effect of family variables and interbirth interval (IBI) on the 2D:4D ratio. RESULTS Birth order, number of siblings (except for younger sisters), and sex ratio in siblings were significantly related to the 2D:4D ratio on the right, left, or both hands. At the same time, the relationships were opposite in males and females for birth order, number of older brothers and number of children in the family--increasing values in these variables increased digit ratio in males but decreased digit ratio in females. Mean difference in 2D:4D ratio (DIFF) within pairs (older minus younger sibling) differed from zero only in the "older sister--younger brother" group, where DIFF did not depend on IBI. On the contrary, in remaining pair types the DIFF tended to change with IBI, the strongest in the "older brother--younger sister" pairs. CONCLUSIONS Family variables, especially number of older brothers, should be considered as important confounding factors in 2D:4D ratio studies. However, the effect of these variables might be modified by IBI.
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Affiliation(s)
- Miroslav Králík
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Adela Hupková
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Tomáš Zeman
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Martin Hložek
- Department of Archaeology and Museology, Faculty of Arts, Masaryk University, Brno, Czech Republic
| | - Lukáš Hlaváček
- Palacký University Olomouc, Conference Services, Olomouc, Czech Republic
| | - Marie Slováčková
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Martin Čuta
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Petra Urbanová
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
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Bakholdina VY, Movsesian AA, Negasheva MA. Association between the digit ratio (2D:4D) and body fat distribution in Mordovian students. Ann Hum Biol 2018; 45:414-418. [PMID: 30328710 DOI: 10.1080/03014460.2018.1495264] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND The length ratio of the second to the fourth finger (2D:4D) is a possible biomarker of prenatal sex hormone levels, which play a significant role in determining sex-related body traits. AIMS To evaluate the value of the 2D:4D ratio in a Mordovian sample and to test the associations between the 2D:4D ratio and sexually dimorphic morphological traits, such as height and body weight, body mass index, waist and hip circumference, the waist-to-hip ratio, handgrip strength and the skinfold thickness. SUBJECTS AND METHODS The sample studied included 106 individuals of Mordovian ethnicity: 58 males and 48 females, 16-23 years old. The associations between the 2D:4D ratio and morphological traits were evaluated by multivariate regression analysis and correlation analysis. RESULTS The 2D:4D ratio in males was significantly lower than in females. Most of the associations of the 2D:4D ratio with morphological traits were statistically insignificant. The 2D:4D ratio is only significantly correlated with skinfold thickness of the forearm and the abdomen in females. CONCLUSION The association between the 2D:4D ratio and skinfold thickness is indicative of the role of prenatal sex hormones in shaping the body fat distribution in females, along with the significant impact of sex hormones at puberty.
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Affiliation(s)
| | - Alla A Movsesian
- a Department of Anthropology , Lomonosov State University , Moscow , Russian
| | - Marina A Negasheva
- a Department of Anthropology , Lomonosov State University , Moscow , Russian
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Sitek A, Kozieł S, Kasielska-Trojan A, Antoszewski B. Do skin and hair pigmentation in prepubertal and early pubertal stages correlate with 2D:4D? Am J Hum Biol 2018; 30:e12631. [PMID: 30260076 DOI: 10.1002/ajhb.23183] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 07/24/2018] [Accepted: 08/28/2018] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES In most human populations women are less pigmented than men. However, before puberty, boys tend to have lighter skin than girls. Previous research has shown that skin pigmentation in European women is negatively correlated with digit ratio (2D:4D). Therefore, it has been hypothesized that skin pigmentation in females is partially controlled by prenatal hormones. The aim of this study was to examine the correlation between 2D:4D and pigmentation in girls and boys in the prepubertal or early pubertal stages of ontogenesis. METHODS The study group consisted of 598 Polish children (275 boys), aged 6.5-10.5 years. All underwent spectrophotometric measurements of skin and hair melanin index (SMI and HMI) and had the second and the fourth finger on both hands measured directly. RESULTS SMI (in girls) and HMI (in girls and boys) were positively correlated with age but 2D:4D was not. We regressed SMI and HMI on age and used the residuals as a measure of age-independent pigmentation. In girls, positive correlations were found between resSMI and 2D:4D for the right hand, but there was no correlation with left 2D:4D. In boys, resSMI did not correlate with 2D:4D. The resHMI was not related to 2D:4D in girls or boys. CONCLUSION Skin pigmentation in prepubertal or early pubertal girls is related to 2D:4D such that high 2D:4D is associated with higher pigmentation. This relationship may be mediated by the individual rate of sexual maturation.
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Affiliation(s)
- Aneta Sitek
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Sławomir Kozieł
- Department of Anthropology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Anna Kasielska-Trojan
- Plastic, Reconstructive and Aesthetic Surgery Clinic, Medical University of Lodz, Lodz, Poland
| | - Bogusław Antoszewski
- Plastic, Reconstructive and Aesthetic Surgery Clinic, Medical University of Lodz, Lodz, Poland
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Pruszkowska-Przybylska P, Sitek A, Rosset I, Sobalska-Kwapis M, Słomka M, Strapagiel D, Żądzińska E. Association of the 2D:4D digit ratio with body composition among the Polish children aged 6-13 years. Early Hum Dev 2018; 124:26-32. [PMID: 30119034 DOI: 10.1016/j.earlhumdev.2018.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/02/2018] [Accepted: 08/07/2018] [Indexed: 12/17/2022]
Abstract
The 2D:4D digit ratio is formed as a result of genetic factors but also prenatal exposure to sex hormones. The higher index value the higher concentration of the prenatal oestrogen. It is commonly known that testosterone is a hormone connected with muscle mass growth and that oestrogen affects adipogenesis. The aim of this study was to find if the digit ratio can be an informative indicator of the fat mass and muscle mass and body proportions in prepubertal children. Material and methods The analysed cohort included 420 children (221 girls and 199 boys) aged 6-13 years. Pearson's and Spearman's tests were conducted to assess whether 2D:4D was significantly correlated with the body composition measurements. Multiple regression models and stepwise forward regression were applied to select the most important independent variables affecting fat mass (%) and muscle mass (%) as well as the BMI and the WHR. Results The study shows that the digit ratio is negatively correlated with muscle mass (MM%) among girls (p < 0.05).There was no similar relationship in the group of boys. The regression models showed a significant role in determining the body composition and body proportions played by maternal factors such as: maternal level of education and weight gain during pregnancy. Conclusions The 2D:4D digit ratio seems to be an informative indicator of the muscle mass development since girls' early childhood. Moreover, maternal environment is also important in forming the offspring's body composition and proportions.
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Affiliation(s)
| | - Aneta Sitek
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Łódź, 90-237, Poland
| | - Iwona Rosset
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Łódź, 90-237, 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 Łódź, 90-237, Poland; Biological Anthropology and Comparative Anatomy Research Unit, School of Medicine, The University of Adelaide, South Australia 5005, Australia
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11
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Del Giudice M, Barrett ES, Belsky J, Hartman S, Martel MM, Sangenstedt S, Kuzawa CW. Individual differences in developmental plasticity: A role for early androgens? Psychoneuroendocrinology 2018; 90:165-173. [PMID: 29500952 PMCID: PMC5864561 DOI: 10.1016/j.psyneuen.2018.02.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 02/20/2018] [Accepted: 02/22/2018] [Indexed: 11/16/2022]
Abstract
Developmental plasticity is a widespread property of living organisms, but different individuals in the same species can vary greatly in how susceptible they are to environmental influences. In humans, research has sought to link variation in plasticity to physiological traits such as stress reactivity, exposure to prenatal stress-related hormones such as cortisol, and specific genes involved in major neurobiological pathways. However, the determinants of individual differences in plasticity are still poorly understood. Here we present the novel hypothesis that, in both sexes, higher exposure to androgens during prenatal and early postnatal life should lead to increased plasticity in traits that display greater male variability (i.e., a majority of physical and behavioral traits). First, we review evidence of greater phenotypic variation and higher susceptibility to environmental factors in males; we then consider evolutionary models that explain greater male variability and plasticity as a result of sexual selection. These empirical and theoretical strands converge on the hypothesis that androgens may promote developmental plasticity, at least for traits that show greater male variability. We discuss a number of potential mechanisms that may mediate this effect (including upregulation of neural plasticity), and address the question of whether androgen-induced plasticity is likely to be adaptive or maladaptive. We conclude by offering suggestions for future studies in this area, and considering some research designs that could be used to empirically test our hypothesis.
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Affiliation(s)
- Marco Del Giudice
- Department of Psychology, University of New Mexico, Albuquerque, NM, USA.
| | - Emily S Barrett
- School of Public Health, Rutgers University, Piscataway, NJ, USA
| | - Jay Belsky
- Department of Human Ecology, University of California - Davis, Davis, CA, USA
| | - Sarah Hartman
- Department of Human Ecology, University of California - Davis, Davis, CA, USA
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12
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Georgiev AV, Ryan CP, Borja JB, Kuzawa CW. Is early postnatal growth velocity, a proxy of minipubertal androgen action, related to adult second‐to‐fourth digit (2D:4D) ratios in men? A test in Cebu, Philippines. Am J Hum Biol 2017; 29. [DOI: 10.1002/ajhb.23047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 05/25/2017] [Accepted: 07/05/2017] [Indexed: 12/19/2022] Open
Affiliation(s)
- Alexander V. Georgiev
- Department of AnthropologyNorthwestern University1810 Hinman Avenue, Evanston Illinois60208
- School of Biological SciencesBangor University, Deiniol RoadBangor GwyneddLL57 2UW United Kingdom
| | - Calen P. Ryan
- Department of AnthropologyNorthwestern University1810 Hinman Avenue, Evanston Illinois60208
| | - Judith B. Borja
- Office of Population Studies Foundation, Inc. and Department of Nutrition and Dietetics, University of San CarlosCebu City Philippines
| | - Christopher W. Kuzawa
- Department of AnthropologyNorthwestern University1810 Hinman Avenue, Evanston Illinois60208
- Institute for Policy ResearchNorthwestern University2040 Sheridan Road, Evanston Illinois60208
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