1
|
Eichler A, Kaufmann F, Titzmann A, Fasching PA, Beckmann MW, Gerlach J, Kratz O, Moll GH, Buchholz VN, Kornhuber J, Lenz B. 2D:4D biomarker reliability and validity in a within-subject pregnancy-childhood-adolescence cohort. Early Hum Dev 2023; 181:105776. [PMID: 37084692 DOI: 10.1016/j.earlhumdev.2023.105776] [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: 02/28/2023] [Revised: 04/11/2023] [Accepted: 04/11/2023] [Indexed: 04/23/2023]
Abstract
BACKGROUND A lot of studies use the second-to-fourth digit length ratio (2D:4D) as a biomarker for intrauterine androgen load to predict behavioral and mental health problems. Thus, knowledge of 2D:4D's metric properties, namely reliability and validity, is essential. METHOD 2D:4D handscans were available from 149 adolescents (M = 13.32 years, SD = 0.35) and their mothers. For 88 adolescents, there were also primary-school age handscans (M = 7.87 years, SD = 0.68). Prenatal risks for the 1st to 3rd trimesters were recorded during the 3rd trimester of pregnancy (alcohol exposition: meconium biomarker and maternal self-report; nicotine exposition: maternal self-report; maternal depressive symptoms and subjective stress: questionnaires). RESULTS The 2D:4D ratio was highly stable from childhood to early adolescence. However, both developmental and sex effects were present: The 2D:4D ratio increased with age and was higher in adolescent girls vs. boys. Significant 2D:4D mother-child associations were found for girls. Significant main effects could be found for the prenatal risk factors alcohol (self-report) and nicotine consumption. CONCLUSION In line with earlier studies, the 2D:4D biomarker proved to be an inter-individually stable measure with an intra-individual increase from childhood to early adolescence. Sex differences in adolescence and associations with maternal prenatal health behaviour underline the validity of the biomarker. Findings on heritability emphasize the importance of interpreting 2D:4D results in a sex-specific manner.
Collapse
Affiliation(s)
- Anna Eichler
- Department of Child and Adolescent Mental Health, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | - Franziska Kaufmann
- Department of Child and Adolescent Mental Health, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Adriana Titzmann
- Department of Obstetrics and Gynecology, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Peter A Fasching
- Department of Obstetrics and Gynecology, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Matthias W Beckmann
- Department of Obstetrics and Gynecology, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Jennifer Gerlach
- Department of Child and Adolescent Mental Health, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Oliver Kratz
- Department of Child and Adolescent Mental Health, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Gunther H Moll
- Department of Child and Adolescent Mental Health, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Verena N Buchholz
- Department of Psychiatry and Psychotherapy, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Bernd Lenz
- Department of Psychiatry and Psychotherapy, University Hospital Erlangen, Friedrich-Alexander-Univesität Erlangen-Nürnberg (FAU), Erlangen, Germany; Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health (CIMH), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| |
Collapse
|
2
|
Finley B, Kalwij A, Kapteyn A. Born to be wild: Second-to-fourth digit length ratio and risk preferences. ECONOMICS AND HUMAN BIOLOGY 2022; 47:101178. [PMID: 36084390 DOI: 10.1016/j.ehb.2022.101178] [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: 05/10/2022] [Revised: 07/20/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
The second-to-fourth digit length ratio of an individual's hand (digit ratio) is a putative biomarker for prenatal exposure to testosterone. We examine the hypothesized negative association between the digit ratio and the preference for risk taking within a large U.S. population survey. Our statistical framework provides a cardinal proxy for the true digit ratio based on ordinal digit ratio measurements and accounts for measurement error under the assumptions of Gaussianity and time-invariant true digit ratios. Our empirical findings support the hypothesis and suggest a meaningful biological basis for risk preferences.
Collapse
Affiliation(s)
| | - Adriaan Kalwij
- Utrecht University School of Economics, The Netherlands.
| | - Arie Kapteyn
- Center for Economic and Social Research at the University of Southern California, United States.
| |
Collapse
|
3
|
Digit ratio (2D:4D) and maternal testosterone-to-estradiol ratio measured in early pregnancy. Sci Rep 2022; 12:13586. [PMID: 35945232 PMCID: PMC9363442 DOI: 10.1038/s41598-022-17247-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 07/22/2022] [Indexed: 11/09/2022] Open
Abstract
The ratio of index to ring finger (2D:4D) has been hypothesised to indicate prenatal androgen exposure, yet evidence for its validity is lacking. We report the first pre-registered study to investigate mothers' early pregnancy sex hormone concentrations in relation to their children's digit ratios measured at 18-22-month follow-up. Although the testosterone (T) to estradiol (E) ratio correlated negatively with right hand digit ratio (R2D:4D) and directional asymmetry (right-minus-left) in digit ratio (D[R-L]), neither effect remained statistically significant once demographic and obstetric covariates were controlled for. Nevertheless, the multivariate level of analysis did reveal that T correlated positively with left hand digit ratio (L2D:4D) and negatively with D[R-L]. However, the first of these effects is in the opposite direction to that predicted by theory. Taken together, the results of our study suggest research with larger samples is required to determine whether digit ratios are valid proxies for maternal sex hormone exposure.
Collapse
|
4
|
Alex AM, Ruvio T, Xia K, Jha SC, Girault JB, Wang L, Li G, Shen D, Cornea E, Styner MA, Gilmore JH, Knickmeyer RC. Influence of gonadal steroids on cortical surface area in infancy. Cereb Cortex 2022; 32:3206-3223. [PMID: 34952542 PMCID: PMC9340392 DOI: 10.1093/cercor/bhab410] [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: 04/09/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/27/2022] Open
Abstract
Sex differences in the human brain emerge as early as mid-gestation and have been linked to sex hormones, particularly testosterone. Here, we analyzed the influence of markers of early sex hormone exposure (polygenic risk score (PRS) for testosterone, salivary testosterone, number of CAG repeats, digit ratios, and PRS for estradiol) on the growth pattern of cortical surface area in a longitudinal cohort of 722 infants. We found PRS for testosterone and right-hand digit ratio to be significantly associated with surface area, but only in females. PRS for testosterone at the most stringent P value threshold was positively associated with surface area development over time. Higher right-hand digit ratio, which is indicative of low prenatal testosterone levels, was negatively related to surface area in females. The current work suggests that variation in testosterone levels during both the prenatal and postnatal period may contribute to cortical surface area development in female infants.
Collapse
Affiliation(s)
- Ann Mary Alex
- Neuroengineering Division, Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Tom Ruvio
- Neuroengineering Division, Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Kai Xia
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
| | - Shaili C Jha
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Jessica B Girault
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
- Carolina Institute for Developmental Disabilities, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Li Wang
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Gang Li
- Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dinggang Shen
- School of Biomedical Engineering, ShanghaiTech University, Shanghai 201210, China
- Department of Artificial Intelligence, Korea University, Seoul 02841, Republic of Korea
| | - Emil Cornea
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
| | - Martin A Styner
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - John H Gilmore
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rebecca C Knickmeyer
- Neuroengineering Division, Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI 48824, USA
- Department of Psychiatry, University of North Carolina Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI 48824, USA
- Center for Research in Autism, Intellectual, and Other Neurodevelopmental Disabilities, Michigan State University, East Lansing, MI 48824, USA
| |
Collapse
|
5
|
Exposure to environmental estrogens and second-to-fourth digit ratio in Greek population: A possible link. Early Hum Dev 2021; 163:105245. [PMID: 33191006 DOI: 10.1016/j.earlhumdev.2020.105245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/25/2020] [Accepted: 10/27/2020] [Indexed: 12/20/2022]
|
6
|
Dinsdale NL, Crespi BJ. Endometriosis and polycystic ovary syndrome are diametric disorders. Evol Appl 2021; 14:1693-1715. [PMID: 34295358 PMCID: PMC8288001 DOI: 10.1111/eva.13244] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/09/2021] [Accepted: 04/10/2021] [Indexed: 12/15/2022] Open
Abstract
Evolutionary and comparative approaches can yield novel insights into human adaptation and disease. Endometriosis and polycystic ovary syndrome (PCOS) each affect up to 10% of women and significantly reduce the health, fertility, and quality of life of those affected. PCOS and endometriosis have yet to be considered as related to one another, although both conditions involve alterations to prenatal testosterone levels and atypical functioning of the hypothalamic-pituitary-gonadal (HPG) axis. Here, we propose and evaluate the novel hypothesis that endometriosis and PCOS represent extreme and diametric (opposite) outcomes of variation in HPG axis development and activity, with endometriosis mediated in notable part by low prenatal and postnatal testosterone, while PCOS is mediated by high prenatal testosterone. This diametric disorder hypothesis predicts that, for characteristics shaped by the HPG axis, including hormonal profiles, reproductive physiology, life-history traits, and body morphology, women with PCOS and women with endometriosis will manifest opposite phenotypes. To evaluate these predictions, we review and synthesize existing evidence from developmental biology, endocrinology, physiology, life history, and epidemiology. The hypothesis of diametric phenotypes between endometriosis and PCOS is strongly supported across these diverse fields of research. Furthermore, the contrasts between endometriosis and PCOS in humans parallel differences among nonhuman animals in effects of low versus high prenatal testosterone on female reproductive traits. These findings suggest that PCOS and endometriosis represent maladaptive extremes of both female life-history variation and expression of sexually dimorphic female reproductive traits. The diametric disorder hypothesis for endometriosis and PCOS provides novel, unifying, proximate, and evolutionary explanations for endometriosis risk, synthesizes diverse lines of research concerning the two most common female reproductive disorders, and generates future avenues of research for improving the quality of life and health of women.
Collapse
Affiliation(s)
| | - Bernard J. Crespi
- Department of Biological SciencesSimon Fraser UniversityBurnabyBCCanada
| |
Collapse
|
7
|
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.
Collapse
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
| | | | | | | | | |
Collapse
|
8
|
Turan Ş, Boysan M, Tarakçıoğlu MC, Sağlam T, Yassa A, Bakay H, Demirel ÖF, Tosun M. 2D:4D Digit Ratios in Adults with Gender Dysphoria: A Comparison to Their Unaffected Same-Sex Heterosexual Siblings, Cisgender Heterosexual Men, and Cisgender Heterosexual Women. ARCHIVES OF SEXUAL BEHAVIOR 2021; 50:885-895. [PMID: 33694048 DOI: 10.1007/s10508-021-01938-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 01/26/2021] [Accepted: 01/30/2021] [Indexed: 06/12/2023]
Abstract
We compared gender dysphoria (GD) patients and their same-sex siblings in terms of their 2D:4D ratios, which may reflect prenatal exposure to androgen, one of the possible etiological mechanisms underlying GD. Sixty-eight GD patients (46 Female-to-Male [FtM]; 22 Male-to-Female [MtF]), 68 siblings (46 sisters of FtMs; 22 brothers of MtFs), and 118 heterosexual controls (62 female; 56 male) were included in the study. FtMs were gynephilic and MtFs were androphilic. We found that 2D:4D ratios in the both right hand (p < .001) and the left hand (p = .003) were lower in male controls than in female controls. Regarding right hands, FtM GD patients had lower 2D:4D ratios than female controls (p < .001) but their ratios did not differ from those of their sisters or male controls. FtM GD patients had no significant difference in their left-hand 2D:4D ratios compared to their sisters or female and male controls. While there was no significant difference in right hands between FtM's sisters and male controls, left-hand 2D:4D ratios were significantly higher in FtM's sisters (p = .017). MtF GD patients had lower right-hand 2D:4D ratios than female controls (p <.001), but their right-hand ratios did not differ from those of their brothers and male controls. There was no significant difference in left-hand 2D:4D ratios between MtF GD patients, and their brothers, or female and male controls. FtM GD patients showed significantly masculinized right-hand 2D:4D ratios, while there was no evidence of feminization in MtF GD patients.
Collapse
Affiliation(s)
- Şenol Turan
- Department of Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Cerrahpaşa-Fatih, 34098, Istanbul, Turkey.
| | - Murat Boysan
- Department of Psychology, Faculty of Social Sciences and Humanities, Ankara Social Sciences University, Ankara, Turkey
| | - Mahmut Cem Tarakçıoğlu
- Department of Child and Adolescent Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Istanbul, Turkey
| | - Tarık Sağlam
- Department of Psychiatry, Halil Şıvgın Çubuk State Hospital, Ankara, Turkey
| | - Ahmet Yassa
- Department of Psychiatry, Yozgat State Hospital, Yozgat, Turkey
| | - Hasan Bakay
- Department of Psychiatry, Nizip State Hospital, Gaziantep, Turkey
| | - Ömer Faruk Demirel
- Department of Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Cerrahpaşa-Fatih, 34098, Istanbul, Turkey
| | - Musa Tosun
- Department of Psychiatry, Cerrahpaşa School of Medicine, Istanbul University-Cerrahpaşa, Cerrahpaşa-Fatih, 34098, Istanbul, Turkey
| |
Collapse
|
9
|
Richards G, Medland SE, Beaton AA. Digit ratio (2D:4D) and handedness: A meta-analysis of the available literature. Laterality 2021; 26:421-484. [PMID: 33517845 DOI: 10.1080/1357650x.2020.1862141] [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] [Indexed: 01/26/2023]
Abstract
The Geschwind-Behan-Galaburda and sexual differentiation models predict an association between elevated foetal androgen exposure and left-handedness whereas the callosal hypothesis predicts the opposite. We present a meta-analysis of correlations between handedness and digit ratio (2D:4D), a putative marker of prenatal testosterone. Left-handedness predicted low (male-typical) right-hand digit ratio (R2D:4D), high (female-typical) left-hand digit ratio (L2D:4D), and low R2D:4D-L2D:4D directional asymmetry (D[R-L]). Effect sizes were extremely small and not moderated by sex or method of measuring handedness or 2D:4D. The same general pattern was observed after excluding the very large study (110,329 males, 90,412 females) of Manning and Peters ([2009]. Digit ratio (2D:4D) and hand preference for writing in the BBC Internet Study. Laterality: Asymmetries of Body, Brain and Cognition, 14(5), 528-540. doi:10.1080/13576500802637872); however, no significant effects for R2D:4D were observed once these samples were removed. The results do not confirm any theory linking prenatal androgens with handedness, so we speculate they instead reflect the mechanical action of writing causing subtle changes in the musculature and/or fat pads of the fingers. Gripping a pen/pencil might cause an increase in 2D relative to 4D (and/or decrease in 4D relative to 2D) resulting in higher ratios on the writing-hand; furthermore, this could differ between left- and right-handers due to writing in the left-to-right direction (as in English) having asymmetrical effects depending on which hand is used.
Collapse
Affiliation(s)
- Gareth Richards
- School of Psychology, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.,Autism Research Centre, Department of Psychiatry, University of Cambridge, Cambridge, UK.,Centre for Research on Play in Education, Development & Learning, Faculty of Education, University of Cambridge, Cambridge, UK
| | - Sarah E Medland
- Psychiatric Genetics, QIMR Berghofer Medical Research Institute, Brisbane, Australia.,School of Psychology, University of Queensland, St Lucia, Australia.,School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia
| | - Alan A Beaton
- Department of Psychology, School of Human & Health Sciences, Swansea University, Swansea, UK.,Department of Psychology, Aberystwyth University, Aberystwyth, UK
| |
Collapse
|
10
|
Effects of hand preference on digit lengths and digit ratios among children and adults. Early Hum Dev 2020; 151:105204. [PMID: 33059164 DOI: 10.1016/j.earlhumdev.2020.105204] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 09/28/2020] [Accepted: 09/29/2020] [Indexed: 01/21/2023]
Abstract
BACKGROUND Prenatal sex hormones may not exclusively determine effects of hand preference on digit ratios. Genetic determination is an alternative possibility. AIM To study the likelihood of similar effects of hand preference on digit lengths and digit ratios. METHODS We selected similar numbers of left-handers and right-handers in samples of kindergarten children (N = 101, age range: 3.5-7 years) and adults (N = 189, age range: 17-28 years) and measured digit lengths (excluding the thumb) directly on the palmar hand. RESULTS Compared to right-handers, left-handers had longer digits and lower third-to-fourth (3D:4D) digit ratios among children, whereas an opposite pattern of handedness differences occurred among adults. CONCLUSIONS Effects of hand preference on digit lengths and ratios might be genetically/ontogenetically determined. Also discussed are implications of this set of findings for digit ratio research.
Collapse
|
11
|
Nazarova GG, Proskurnyak LP, Yuzhik EI. Dependence of the Ratio of the Lengths for the Second and Fourth Fingers (2D : 4D) on the Prenatal Development Conditions in Water Vole (Arvicola amphibius L.). Russ J Dev Biol 2020. [DOI: 10.1134/s1062360420010051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
12
|
Kalichman L, Batsevich V, Kobyliansky E. Heritability estimation of 2D:4D finger ratio in a Chuvashian population-based sample. Am J Hum Biol 2019; 31:e23212. [PMID: 30635958 DOI: 10.1002/ajhb.23212] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 08/30/2018] [Accepted: 12/01/2018] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVES The purpose of this study was to evaluate the familial correlations and heritability of 2D:4D ratio traits using a large population-based sample of ethnically homogeneous pedigrees from Chuvasha and Bashkortostan Autonomies of the Russian Federation. METHODS We calculated the familial correlations and performed a heritability analysis of 2D:4D ratio traits in a sample of 1541 subjects (803 men and 738 women, mean age 47.78 ± 16.89 years, range 18-90 years). RESULTS Familial correlations of 2D:4D ratio traits showed no significant correlation for spouses; however, parent-offspring (0.15-0.28, P < .001) and sibling correlations (0.13-0.38, P < .009) were found to be significant. Heritability (H2 ) of visual classification of 2D:4D ratio was 0.36 for the left and 0.28 for the right hand; finger ratio was 0.55 and 0.66, respectively; the ray ratio was 0.49 and 0.59, respectively, thus indicating the existence of a clear familial aggregation of 2D:4D ratio variation in the Chuvashian pedigrees, which cannot be explained only by common environmental effects. DISCUSSION Results of our study suggest familial aggregations of finger ratio variation (for all traits) in Chuvashian pedigrees. No evidence of assortative mating was found.
Collapse
Affiliation(s)
- Leonid Kalichman
- Department of Physical Therapy, Recanati School for Community Health Professions, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Valery Batsevich
- Research Institute and Museum of Anthropology, Moscow State University, Moscow, Russia
| | - Eugene Kobyliansky
- Human Population Biology Research Unit, Department of Anatomy and Anthropology, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
13
|
Nishimura Y, Moriya K, Kobayashi S, Araki A, Sata F, Mitsui T, Itoh S, Miyashita C, Cho K, Kon M, Nakamura M, Kitta T, Murai S, Kishi R, Shinohara N. Association between ESR1 polymorphisms and second to fourth digit ratio in school-aged children in the Hokkaido Study. Steroids 2019; 141:55-62. [PMID: 30468784 DOI: 10.1016/j.steroids.2018.11.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/14/2018] [Accepted: 11/17/2018] [Indexed: 01/28/2023]
Abstract
The ratio of the lengths of the 2nd and 4th digits (2D:4D) is considered an index of prenatal exposure to androgen. Indeed, androgen receptors have been linked to digit length, but estrogen receptors are rarely investigated in this context. Thus, we investigated the association between estrogen receptor 1 (ESR1) genetic polymorphisms and 2D:4D in school-aged children. The 2D:4D ratios were determined using Vernier calipers from photocopies of palms provided by 1800 children aged 7 years who were enrolled in an ongoing prospective cohort study in Hokkaido, Japan. The children were genotyped using cord blood collected at birth for single nucleotide polymorphisms in ESR1, specifically PvuII (T > C, dbSNP: rs2234693), XbaI (A > G, dbSNP: rs9340799), and rs2077647 (A > G). The association between ESR1 polymorphisms and 2D:4D was assessed by multiple linear regression adjusted for potential cofounding factors. Boys with the GG genotype at rs9340799 had a significantly lower 2D:4D in the right hand than boys with the AA/AG genotype (-0.96% lower, 95% confidence interval: -1.68 to -0.24). However, this association was detected only in boys born to non-smoking mothers. No significant differences were found between rs9340799 polymorphisms and 2D:4D among girls. There was also no link between 2D:4D and polymorphisms at rs2234693 and rs2077647. These data suggest that rs9340799 polymorphisms in ESR1 may contribute to digit length and 2D:4D.
Collapse
Affiliation(s)
- Yoko Nishimura
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo 060-8638, Japan; Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan
| | - Kimihiko Moriya
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo 060-8638, Japan.
| | - Sumitaka Kobayashi
- Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan
| | - Atsuko Araki
- Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan
| | - Fumihiro Sata
- Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan; Health Center, Chuo University, 42-8, Ichigaya-Hommura-cho, Shinjuku-ku, Tokyo 162-8473, Japan
| | - Takahiko Mitsui
- Department of Urology, Graduate School of Medical Science, University of Yamanashi, Simokato-1110, Chuo 409-3898, Japan
| | - Sachiko Itoh
- Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan
| | - Chihiro Miyashita
- Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan
| | - Kazutoshi Cho
- Maternity and Perinatal Care Center, Hokkaido University Hospital, North-14, West-5 Kita-ku, Sapporo 060-8648, Japan
| | - Masafumi Kon
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo 060-8638, Japan
| | - Michiko Nakamura
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo 060-8638, Japan
| | - Takeya Kitta
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo 060-8638, Japan
| | - Sachiyo Murai
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo 060-8638, Japan
| | - Reiko Kishi
- Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan
| | - Nobuo Shinohara
- Department of Renal and Genitourinary Surgery, Hokkaido University Graduate School of Medicine, North-15, West-7, Kita-ku, Sapporo 060-8638, Japan
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Warrington NM, Shevroja E, Hemani G, Hysi PG, Jiang Y, Auton A, Boer CG, Mangino M, Wang CA, Kemp JP, McMahon G, Medina-Gomez C, Hickey M, Trajanoska K, Wolke D, Ikram MA, Montgomery GW, Felix JF, Wright MJ, Mackey DA, Jaddoe VW, Martin NG, Tung JY, Davey Smith G, Pennell CE, Spector TD, van Meurs J, Rivadeneira F, Medland SE, Evans DM. Genome-wide association study identifies nine novel loci for 2D:4D finger ratio, a putative retrospective biomarker of testosterone exposure in utero. Hum Mol Genet 2018; 27:2025-2038. [PMID: 29659830 PMCID: PMC5961159 DOI: 10.1093/hmg/ddy121] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 03/12/2018] [Accepted: 04/03/2018] [Indexed: 02/06/2023] Open
Abstract
The ratio of the length of the index finger to that of the ring finger (2D:4D) is sexually dimorphic and is commonly used as a non-invasive biomarker of prenatal androgen exposure. Most association studies of 2D:4D ratio with a diverse range of sex-specific traits have typically involved small sample sizes and have been difficult to replicate, raising questions around the utility and precise meaning of the measure. In the largest genome-wide association meta-analysis of 2D:4D ratio to date (N = 15 661, with replication N = 75 821), we identified 11 loci (9 novel) explaining 3.8% of the variance in mean 2D:4D ratio. We also found weak evidence for association (β = 0.06; P = 0.02) between 2D:4D ratio and sensitivity to testosterone [length of the CAG microsatellite repeat in the androgen receptor (AR) gene] in females only. Furthermore, genetic variants associated with (adult) testosterone levels and/or sex hormone-binding globulin were not associated with 2D:4D ratio in our sample. Although we were unable to find strong evidence from our genetic study to support the hypothesis that 2D:4D ratio is a direct biomarker of prenatal exposure to androgens in healthy individuals, our findings do not explicitly exclude this possibility, and pathways involving testosterone may become apparent as the size of the discovery sample increases further. Our findings provide new insight into the underlying biology shaping 2D:4D variation in the general population.
Collapse
Affiliation(s)
- Nicole M Warrington
- The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, QLD 4102, Australia
- Queensland Institute of Medical Research, Brisbane, QLD 4006, Australia
- Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, WA 6009, Australia
| | - Enisa Shevroja
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Gibran Hemani
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - Pirro G Hysi
- Department of Twin Research and Genetic Epidemiology, King’s College London, London SE1 7EH, UK
| | | | - Adam Auton
- 23andMe, Inc., Mountain View, CA 94061, USA
| | - Cindy G Boer
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Massimo Mangino
- Department of Twin Research and Genetic Epidemiology, King’s College London, London SE1 7EH, UK
| | - Carol A Wang
- Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, WA 6009, Australia
- School of Medicine and Public Health, Faculty of Medicine and Health, The University of Newcastle, Newcastle, NSW 2308, Australia
| | - John P Kemp
- The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, QLD 4102, Australia
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - George McMahon
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - Carolina Medina-Gomez
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | - Martha Hickey
- Department of Obstetrics and Gynaecology, The University of Melbourne and the Royal Women’s Hospital, Parkville, VIC 3052, Australia
| | - Katerina Trajanoska
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | - Dieter Wolke
- Department of Psychology and Warwick Medical School, University of Warwick, Coventry CV47AL, UK
| | - M Arfan Ikram
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | | | - Grant W Montgomery
- Queensland Brain Institute and Centre for Advanced Imaging, University of Queensland, Brisbane, QLD 4072, Australia
| | - Janine F Felix
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Margaret J Wright
- Queensland Brain Institute and Centre for Advanced Imaging, University of Queensland, Brisbane, QLD 4072, Australia
| | - David A Mackey
- Lions Eye Institute, Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia
| | - Vincent W Jaddoe
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Nicholas G Martin
- Queensland Institute of Medical Research, Brisbane, QLD 4006, Australia
| | | | - George Davey Smith
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - Craig E Pennell
- Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, WA 6009, Australia
- School of Medicine and Public Health, Faculty of Medicine and Health, The University of Newcastle, Newcastle, NSW 2308, Australia
| | - Tim D Spector
- Department of Twin Research and Genetic Epidemiology, King’s College London, London SE1 7EH, UK
| | - Joyce van Meurs
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
| | - Fernando Rivadeneira
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | - Sarah E Medland
- Queensland Institute of Medical Research, Brisbane, QLD 4006, Australia
| | - David M Evans
- The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, QLD 4102, Australia
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| |
Collapse
|
16
|
Warrington NM, Shevroja E, Hemani G, Hysi PG, Jiang Y, Auton A, Boer CG, Mangino M, Wang CA, Kemp JP, McMahon G, Medina-Gomez C, Hickey M, Trajanoska K, Wolke D, Ikram MA, Montgomery GW, Felix JF, Wright MJ, Mackey DA, Jaddoe VW, Martin NG, Tung JY, Davey Smith G, Pennell CE, Spector TD, van Meurs J, Rivadeneira F, Medland SE, Evans DM. Genome-wide association study identifies nine novel loci for 2D:4D finger ratio, a putative retrospective biomarker of testosterone exposure in utero. Hum Mol Genet 2018; 27:2025-2038. [PMID: 29659830 PMCID: PMC5961159 DOI: 10.1093/hmg/ddy121 10.1093/hmg/ddy121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 03/12/2018] [Accepted: 04/03/2018] [Indexed: 10/22/2023] Open
Abstract
The ratio of the length of the index finger to that of the ring finger (2D:4D) is sexually dimorphic and is commonly used as a non-invasive biomarker of prenatal androgen exposure. Most association studies of 2D:4D ratio with a diverse range of sex-specific traits have typically involved small sample sizes and have been difficult to replicate, raising questions around the utility and precise meaning of the measure. In the largest genome-wide association meta-analysis of 2D:4D ratio to date (N = 15 661, with replication N = 75 821), we identified 11 loci (9 novel) explaining 3.8% of the variance in mean 2D:4D ratio. We also found weak evidence for association (β = 0.06; P = 0.02) between 2D:4D ratio and sensitivity to testosterone [length of the CAG microsatellite repeat in the androgen receptor (AR) gene] in females only. Furthermore, genetic variants associated with (adult) testosterone levels and/or sex hormone-binding globulin were not associated with 2D:4D ratio in our sample. Although we were unable to find strong evidence from our genetic study to support the hypothesis that 2D:4D ratio is a direct biomarker of prenatal exposure to androgens in healthy individuals, our findings do not explicitly exclude this possibility, and pathways involving testosterone may become apparent as the size of the discovery sample increases further. Our findings provide new insight into the underlying biology shaping 2D:4D variation in the general population.
Collapse
Affiliation(s)
- Nicole M Warrington
- The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, QLD 4102, Australia
- Queensland Institute of Medical Research, Brisbane, QLD 4006, Australia
- Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, WA 6009, Australia
| | - Enisa Shevroja
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Gibran Hemani
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - Pirro G Hysi
- Department of Twin Research and Genetic Epidemiology, King’s College London, London SE1 7EH, UK
| | | | - Adam Auton
- 23andMe, Inc., Mountain View, CA 94061, USA
| | - Cindy G Boer
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Massimo Mangino
- Department of Twin Research and Genetic Epidemiology, King’s College London, London SE1 7EH, UK
| | - Carol A Wang
- Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, WA 6009, Australia
- School of Medicine and Public Health, Faculty of Medicine and Health, The University of Newcastle, Newcastle, NSW 2308, Australia
| | - John P Kemp
- The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, QLD 4102, Australia
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - George McMahon
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - Carolina Medina-Gomez
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | - Martha Hickey
- Department of Obstetrics and Gynaecology, The University of Melbourne and the Royal Women’s Hospital, Parkville, VIC 3052, Australia
| | - Katerina Trajanoska
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | - Dieter Wolke
- Department of Psychology and Warwick Medical School, University of Warwick, Coventry CV47AL, UK
| | - M Arfan Ikram
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | | | - Grant W Montgomery
- Queensland Brain Institute and Centre for Advanced Imaging, University of Queensland, Brisbane, QLD 4072, Australia
| | - Janine F Felix
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Margaret J Wright
- Queensland Brain Institute and Centre for Advanced Imaging, University of Queensland, Brisbane, QLD 4072, Australia
| | - David A Mackey
- Lions Eye Institute, Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, WA 6009, Australia
| | - Vincent W Jaddoe
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
| | - Nicholas G Martin
- Queensland Institute of Medical Research, Brisbane, QLD 4006, Australia
| | | | - George Davey Smith
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| | - Craig E Pennell
- Division of Obstetrics and Gynaecology, The University of Western Australia, Perth, WA 6009, Australia
- School of Medicine and Public Health, Faculty of Medicine and Health, The University of Newcastle, Newcastle, NSW 2308, Australia
| | - Tim D Spector
- Department of Twin Research and Genetic Epidemiology, King’s College London, London SE1 7EH, UK
| | - Joyce van Meurs
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
| | - Fernando Rivadeneira
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, South Holland, The Netherlands
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, 3015 CN, Rotterdam, Netherlands
| | - Sarah E Medland
- Queensland Institute of Medical Research, Brisbane, QLD 4006, Australia
| | - David M Evans
- The University of Queensland Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, QLD 4102, Australia
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol BS8 2BN, UK
- Population Health Sciences, University of Bristol, Bristol BS8 2PS, UK
| |
Collapse
|
17
|
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.
Collapse
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
| | | | | | | |
Collapse
|
18
|
Pasterski V. Fetal Androgens and Human Sexual Orientation: Searching for the Elusive Link. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:1615-1619. [PMID: 28660433 PMCID: PMC5529473 DOI: 10.1007/s10508-017-1021-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 06/17/2017] [Indexed: 05/04/2023]
Affiliation(s)
- Vickie Pasterski
- Department of Psychology, University of Cambridge, Free School Lane, Cambridge, CB2 3RQ, UK.
| |
Collapse
|
19
|
Yokoi T, Uemura T, Kazuki K, Onode E, Shintani K, Okada M, Nakamura H. Low second to fourth digit ratio in Dupuytren disease. Medicine (Baltimore) 2017; 96:e7801. [PMID: 28816972 PMCID: PMC5571709 DOI: 10.1097/md.0000000000007801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The ratio of the lengths of the second and fourth digits (2D:4D) has been described as reflecting endogenous prenatal androgen exposure. In general, 2D:4D is lower in men than in women and has potential as a biomarker or predictor for various diseases, athletic ability, and academic performance. Dupuytren disease has digital flexion contractures and is known to predominate in men, but the pathogenesis of the disease remains unclear. To clarify the relationships between Dupuytren disease and endogenous androgens, we performed a retrospective analysis of hand radiographs to investigate 2D:4D in Dupuytren disease. The study included male patients with Dupuytren disease (n = 22) and a control group (n = 18) of male patients with carpal tunnel syndrome. Only unaffected hands, without contractures or osteoarthritis, were evaluated for the purpose of radiographic assessment. The lengths of the phalanx and metacarpal bones in the second and fourth digits were measured by 2 independent observers who each performed 2 sets of measurements separated by a minimum 1-week interval. The 2D:4D was calculated separately for the phalanges and metacarpals, and a combined (phalanx + metacarpal) 2D:4D was also calculated. The reliability of the observer measurements was established using the intraclass correlation coefficient, and both the intra- and interobserver reliability showed excellent agreement. We found that compared with control group, the Dupuytren disease group had significantly lower phalanx and combined 2D:4D. These findings suggest that endogenous prenatal androgens could contribute to the development of Dupuytren disease, leading to its characteristic clinical presentation predominantly in men and affecting the ulnar rays.
Collapse
Affiliation(s)
- Takuya Yokoi
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka
| | - Takuya Uemura
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka
| | | | - Ema Onode
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka
| | - Kosuke Shintani
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka
| | - Mitsuhiro Okada
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka
| | - Hiroaki Nakamura
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka
| |
Collapse
|
20
|
Abstract
Studies have found positive correlations between prenatal exposure to testosterone and masculinization of offspring traits, particularly among females. The present study sought to determine if physical or sexual activity by the mother during pregnancy was related to masculinized/defeminized offspring traits in adulthood. Data were obtained from a large sample of North American college students (offspring) and their mothers. Information about maternal activity levels during pregnancy were reported retrospectively by each mother. The offspring provided self-ratings of various sexually dimorphic traits. Several significant correlations were found. By and large, as maternal physical activity increased, feminine mannerisms decreased and masculine mannerisms increased in the offspring, particularly for females. Maternal physical activity was also associated with increased upper- and lower-body strength and especially with adult height among offspring. Sexual activity by the mother was only associated with upper-body strength and adult height, particularly of the female offspring. Several sexually dimorphic physical traits in offspring are associated with maternal activity levels during pregnancy. Prenatal testosterone is almost certainly involved. The associations could either reflect genetic influences (given that prenatal testosterone is highly heritable) or an effect of maternal testosterone being transferred to the developing fetus. More research is needed to assess the relative merit of these two possibilities.
Collapse
|
21
|
Canan F, Karaca S, Düzgün M, Erdem AM, Karaçaylı E, Topan NB, Lee SK, Zhai ZW, Kuloğlu M, Potenza MN. The relationship between second-to-fourth digit (2D:4D) ratios and problematic and pathological Internet use among Turkish university students. J Behav Addict 2017; 6:30-41. [PMID: 28358645 PMCID: PMC5573004 DOI: 10.1556/2006.6.2017.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Background and aims The ratio of the second and fourth fingers (2D:4D ratio) is a sexually dimorphic trait, with men tending to have lower values than women. This ratio has been related to prenatal testosterone concentrations and addictive behaviors including problematic video-gaming. We aimed to investigate the possible association between 2D:4D ratios and Internet addiction and whether such a relationship would be independent of impulsivity. Methods A total of 652 university students (369 women, 283 men), aged 17-27 years, were enrolled in the study. Problematic and pathological Internet use (PPIU) was assessed using the Internet Addiction Test (IAT). The participants also completed the Barratt Impulsiveness Scale (version 11; BIS-11) and had their 2D:4D ratios measured. Results 2D:4D ratios were not significantly different in women with PPIU and in those with adaptive Internet use (AIU). Men with PPIU exhibited lower 2D:4D ratios on both hands when compared with those with AIU. Correlation analysis revealed that 2D:4D ratios on both hands were negatively correlated with IAT scores among men, but not among women. The multiple linear regression analysis revealed that age, duration of weekly Internet use, impulsiveness, and 2D:4D ratios on the right hand were independently associated with IAT scores among men, and impulsivity did not mediate the relationship between 2D:4D ratios and PPIU. Conclusions For men, 2D:4D ratios on the right hand were inversely correlated with Internet addiction severity even after controlling for individual differences in impulsivity. These findings suggest that high prenatal testosterone levels may contribute to the occurrence of PPIU among men.
Collapse
Affiliation(s)
- Fatih Canan
- Department of Psychiatry, Yale School of
Medicine, New Haven, CT, USA,Corresponding author: Fatih Canan; Department of
Psychiatry, Yale School of Medicine, New Haven, CT 06510, USA; Phone: +1 203
8922744; Fax: +1 203 9747366; E-mail:
| | - Servet Karaca
- Department of Psychiatry, Akdeniz
University School of Medicine, Antalya,
Turkey
| | - Melike Düzgün
- Akdeniz University School of
Medicine, Antalya, Turkey
| | | | | | | | - Sang-Kyu Lee
- Department of Psychiatry, Hallym
University Medical Center, Chuncheon Sacred Heart Hospital,
Chuncheon, South Korea
| | - Zu Wei Zhai
- Department of Psychiatry, Yale School of
Medicine, New Haven, CT, USA
| | - Murat Kuloğlu
- Department of Psychiatry, Akdeniz
University School of Medicine, Antalya,
Turkey
| | - Marc N. Potenza
- Department of Psychiatry, Yale School of
Medicine, New Haven, CT, USA,The National Center on Addiction and Substance Abuse,
Yale School of Medicine, New Haven, CT,
USA,The Connecticut Mental Health
Center, New Haven, CT, USA,Department of Neuroscience and Child Study Center,
Yale School of Medicine, New Haven, CT,
USA
| |
Collapse
|
22
|
Abstract
This paper contributes to a better understanding of the biological underpinnings of overconfidence by analyzing performance predictions in the Cognitive Reflection Test with and without monetary incentives. In line with the existing literature we find that the participants are too optimistic about their performance on average; incentives lead to higher performance; and males score higher than females on this particular task. The novelty of this paper is an analysis of the relation between participants’ performance prediction accuracy and their second to fourth digit ratio. It has been reported that the digit ratio is a negatively correlated bio-marker of prenatal testosterone exposure. In the un-incentivized treatment, we find that males with low digit ratios, on average, are significantly more overconfident about their performance. In the incentivized treatment, however, we observe that males with low digit ratios, on average, are less overconfident about their performance. These effects are not observed in females. We discuss how these findings fit into the literature on testosterone and decision making and how they might help to explain seemingly opposing evidence.
Collapse
|
23
|
Ellis L, Skorska MN, Bogaert AF. Handedness, sexual orientation, and somatic markers for prenatal androgens: Are southpaws really that gay? Laterality 2016; 22:157-180. [DOI: 10.1080/1357650x.2016.1151024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
24
|
Ellis L, Lykins A, Hoskin A, Ratnasingam M. Putative Androgen Exposure and Sexual Orientation: Cross-Cultural Evidence Suggesting a Modified Neurohormonal Theory. J Sex Med 2015; 12:2364-77. [PMID: 26663858 DOI: 10.1111/jsm.13070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION According to neurohormonal theory, prenatal androgens are key determinants of sexual orientation. As a reputed marker for prenatal androgens, the 2D:4D finger length ratio has been used in more than a dozen studies to test the hypothesis that prenatal androgens influence sexual orientation. Findings have been very inconsistent. AIM The present study sought to retest the hypothesis that 2D:4D and sexual orientation are related is a manner consistent with neurohormonal theory. METHODS A 2D:4D measure (of the right hand) along with four additional somatic markers of androgen exposure (height, physical strength, muscularity, and athletic ability) with samples of college students in Malaysia (N = 2,058) and the United States (N = 2,511). The five androgen measures were factor analyzed, resulting in a two-factor solution: Factor 1 consisted of strength, muscularity, and athletic ability (the muscular coordination factor), and Factor 2 was comprised of the r2D:4D and adult height (the bone growth factor). MAIN OUTCOME MEASURES Sexual orientation was measured by asking each respondent the extent to which they were sexually attracted to males and the extent to which they were sexually attracted to females, both on 11-point scales. RESULTS When the countries and sexes were analyzed separately, neither the r2D:4D measure nor Factor 2 correlated with sexual orientation to significant degrees. Instead, it was the muscular coordination factor that correlated the best. Support was found for the hypothesis that prenatal androgens influence sexual orientation, but the nature of these influences was more complex than neurohormonal theory predicted. CONCLUSION A modified theory is needed and presented to accommodate the results from this study.
Collapse
Affiliation(s)
- Lee Ellis
- University of Malaya, Kuala Lumpur, Malaysia
| | - Amy Lykins
- University of New England, Armidale, NSW, Australia
| | | | | |
Collapse
|
25
|
A unique pattern of finger lengths. J ANAT SOC INDIA 2015. [DOI: 10.1016/j.jasi.2015.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
26
|
Romann M, Fuchslocher J. Validation of digit-length ratio (2D:4D) assessments on the basis of DXA-derived hand scans. BMC Med Imaging 2015; 15:1. [PMID: 25645550 PMCID: PMC4323124 DOI: 10.1186/s12880-015-0042-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 01/08/2015] [Indexed: 11/10/2022] Open
Abstract
Background The second-to-fourth digit-length ratio (2D:4D) may be a correlate of prenatal sex steroids, and it has been linked to sporting prowess. The aim of the study was to validate dual-energy X-ray-absorptiometry (DXA) as a technique to assess 2D:4D in soccer players under 15 years of age (U-15). Methods Paired X-ray and DXA scans of the left hands of 63 male U-15 elite soccer players (age: 14.0 ± 0.3 years) were performed, and 2D:4D was then compared between the two techniques. The 2D:4D measurements were performed twice by two blinded raters. Intrarater and interrater reliability, as well as agreement between the X-ray and the DXA assessments, were tested. Results Intrarater reliabilities of both raters using X-ray with intraclass correlation coefficients (ICCs) of 0.97 and 0.90 were excellent. Using DXA, the ICCs were 0.90 and 0.91 thus also showing excellent reliability. Interrater reliabilities were excellent using both the X-ray (ICC of 0.94) and the DXA (ICC of 0.90), assessments respectively. Bland-Altman plots demonstrated that the 2D:4D ratios of the two raters did not differ significantly between the X-ray and the DXA assessments. The standard errors of estimate were 0.01 for both techniques. The 95% limits of agreement of ±0.018 (±2.0%) and ±0.023 (±2.6%), respectively, were within the acceptable tolerance of 5%, and showed very good agreement. Conclusion DXA offered a replicable technique for assessing 2D:4D in youth soccer players. Therefore, the DXA technique seems to be an alternative method for evaluating 2D:4D in youth sports.
Collapse
Affiliation(s)
- Michael Romann
- Swiss Federal Institute of Sport Magglingen, CH-2532, Magglingen, Switzerland.
| | - Jörg Fuchslocher
- Swiss Federal Institute of Sport Magglingen, CH-2532, Magglingen, Switzerland.
| |
Collapse
|
27
|
The 2D:4D digit ratio and social behaviour in wild female chacma baboons (Papio ursinus) in relation to dominance, aggression, interest in infants, affiliation and heritability. Behav Ecol Sociobiol 2014. [DOI: 10.1007/s00265-014-1817-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
28
|
Fouqueray TD, Blumstein DT, Monclús R, Martin JGA. Maternal effects on anogenital distance in a wild marmot population. PLoS One 2014; 9:e92718. [PMID: 24651864 PMCID: PMC3961422 DOI: 10.1371/journal.pone.0092718] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 02/25/2014] [Indexed: 11/18/2022] Open
Abstract
In mammals, prenatal exposure to sex steroid hormones may have profound effects on later behavior and fitness and have been reported under both laboratory and field conditions. Anogenital distance is a non-invasive measure of prenatal exposure to sex steroid hormones. While we know that intra-uterine position and litter sex ratio influence anogenital distance, there are other, heretofore unstudied, factors that could influence anogenital distance, including maternal effects. We capitalized on a long-term study of wild yellow-bellied marmots (Marmota flaviventris) to study the importance of maternal effects on explaining variation in anogenital distance and found significant effects. The strength of these effects varied annually. Taken together, our data highlights the strong variability due to environmental effects, and illustrates the importance of additive genetic and maternal genetic effects on neonatal anogenital distance. We suspect that, as others apply recently popularised quantitative genetic techniques to study free-living populations, such effects will be identified in other systems.
Collapse
Affiliation(s)
- Timothée D. Fouqueray
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
- Département de Biologie, École Normale Supeérieure de Lyon, Lyon, France
| | - Daniel T. Blumstein
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
- The Rocky Mountain Biological Laboratory, Crested Butte, Colorado, United States of America
| | - Raquel Monclús
- Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | - Julien G. A. Martin
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, United States of America
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
- * E-mail:
| |
Collapse
|
29
|
Kothari R, Gafton J, Treasure J, Micali N. 2D:4D ratio in children at familial high-risk for eating disorders: The role of prenatal testosterone exposure. Am J Hum Biol 2013; 26:176-82. [PMID: 24323736 PMCID: PMC3992907 DOI: 10.1002/ajhb.22495] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/13/2013] [Accepted: 11/25/2013] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Markers of prenatal hormone exposure have been associated with the development of eating disorder (ED) behaviors. Our aim was to determine whether 2D:4D ratio, a marker for in utero testosterone exposure, is associated with risk for ED in a large population-based cohort: the Avon Longitudinal Study of Parents and Children (ALSPAC). METHODS This is the first study to investigate prenatal testosterone exposure in children at high-risk for ED, using 2D:4D as a marker. We compared children whose mothers reported a lifetime ED (anorexia, bulimia, or both; N = 446) to children whose mothers did not (n = 5,367). RESULTS Daughters of women with lifetime bulimia nervosa (BN) had lower 2D:4D ratio (B: -0.01, 95% CI: -0.02 to -0.002, P = 0.02), indicating higher prenatal testosterone exposure, than daughters of mothers unaffected by ED. No differences were observed in the male children of women with an ED. CONCLUSIONS Findings suggest that children at high-risk for BN may be exposed to higher levels of testosterone in utero. Fetal exposure to androgen excess is thought to be causal in the development of polycystic ovary syndrome (PCOS), a disorder which is highly comorbid with binge eating and BN. Future research should investigate the potential role of testosterone exposure in utero as a risk factor for BN and binge eating.
Collapse
Affiliation(s)
- Radha Kothari
- Behavioral and Brain Sciences Unit, UCL Institute of Child Health, London, United Kingdom
| | | | | | | |
Collapse
|
30
|
Özener B, Hurd PL, Duyar İ. Inbreeding is associated with lower 2D: 4D digit ratio. Am J Hum Biol 2013; 26:183-8. [DOI: 10.1002/ajhb.22491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 11/11/2013] [Accepted: 11/12/2013] [Indexed: 12/24/2022] Open
Affiliation(s)
- Baris Özener
- Faculty of Literature; Department of Anthropology; Cumhuriyet University; Sivas Turkey
| | - Peter L. Hurd
- Department of Psychology; University of Alberta; Edmonton, T6G 2E9 AB Canada
- Centre for Neuroscience, University of Alberta; Edmonton, T6G 2E9 AB Canada
| | - İzzet Duyar
- Department of Anthropology; Faculty of Literature; İstanbul University; İstanbul Turkey
| |
Collapse
|
31
|
Kalichman L, Batsevich V, Kobyliansky E. 2D:4D finger length ratio and reproductive indices in a Chuvashian population. Am J Hum Biol 2013; 25:617-21. [DOI: 10.1002/ajhb.22420] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 04/03/2013] [Accepted: 05/24/2013] [Indexed: 12/26/2022] Open
Affiliation(s)
- Leonid Kalichman
- Department of Physical Therapy; Recanati School for Community Health Professions, Faculty of Health Sciences, Ben-Gurion University of the Negev; Beer Sheva Israel
| | - Valery Batsevich
- Research Institute and Museum of Anthropology; Moscow State University; Moscow Russia
| | - Eugene Kobyliansky
- Human Population Biology Research Unit, Department of Anatomy and Anthropology; Tel Aviv University; Tel Aviv Israel
- Lilian and Marcel Pollak Chair of Biological Anthropology. Sackler Faculty of Medicine; Tel Aviv University; Tel Aviv Israel
| |
Collapse
|
32
|
Butovskaya M, Fedenok J, Burkova V, Manning J. Sex differences in 2D:4D and aggression in children and adolescents from five regions of Russia. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 152:130-9. [DOI: 10.1002/ajpa.22337] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 05/26/2013] [Accepted: 06/20/2013] [Indexed: 01/30/2023]
Affiliation(s)
- Marina Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences; Moscow; 119991; Russia
| | - Julija Fedenok
- Institute of Ethnology and Anthropology, Russian Academy of Sciences; Moscow; 119991; Russia
| | - Valentina Burkova
- Institute of Ethnology and Anthropology, Russian Academy of Sciences; Moscow; 119991; Russia
| | - John Manning
- Applied Sports Technology Exercise and Medicine Research Centre; Swansea University; Swansea; SA2 8PP; UK
| |
Collapse
|
33
|
PERCIAVALLE VALENTINA, DI CORRADO DONATELLA, PETRALIA MARIACRISTINA, GURRISI LINO, MASSIMINO SIMONA, COCO MARINELLA. The second-to-fourth digit ratio correlates with aggressive behavior in professional soccer players. Mol Med Rep 2013; 7:1733-8. [PMID: 23588344 PMCID: PMC3694562 DOI: 10.3892/mmr.2013.1426] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/29/2013] [Indexed: 11/08/2022] Open
Abstract
The aim of this study was to test the hypothesis that high levels of testosterone during prenatal life, testified by a low second-to-fourth digit ratio (2D:4D), as well as in adulthood affect the aggressive behavior of professional soccer players. Using 18 male professional players from a first level Italian Soccer Team we calculated: i) the 2D:4D ratio of the right hand, ii) the number of yellow and red cards per game, iii) the mean salivary testosterone concentration (Sal/T) and iv) the handling of aggressive impulses as assessed by the Picture Frustration test (PFT). Soccer players with a lower 2D:4D ratio had a higher number of fouls per game. A significant negative correlation was observed between Sal/T and 2D:4D ratio, as well as between 2D:4D ratio and the aggressiveness of players. By contrast, a significant positive correlation of Sal/T and fouls/game score and PFT was detected. No significant correlation was detected between 2D:4D or Sal/T and the playing position of players. Results of this study revealed that in professional soccer players, aggressive behavior, with the consequent increased risk of fouls during the game, is more likely to occur in individuals with high testosterone levels, not only in adulthood, but also during their intrauterine life.
Collapse
Affiliation(s)
- VALENTINA PERCIAVALLE
- Department of Sciences of Formation, Section of Physiology, University of Catania, Catania, Italy
| | | | - MARIA CRISTINA PETRALIA
- Department of Sciences of Formation, Section of Physiology, University of Catania, Catania, Italy
| | - LINO GURRISI
- Department of Bio-Medical Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - SIMONA MASSIMINO
- Department of Bio-Medical Sciences, Section of Physiology, University of Catania, Catania, Italy
| | - MARINELLA COCO
- Department of Bio-Medical Sciences, Section of Physiology, University of Catania, Catania, Italy
| |
Collapse
|
34
|
Kalichman L, Zorina D, Batsevich V, Kobyliansky E. 2D:4D finger length ratio in the Chuvashian population. HOMO-JOURNAL OF COMPARATIVE HUMAN BIOLOGY 2013; 64:233-40. [PMID: 23642797 DOI: 10.1016/j.jchb.2013.02.051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Accepted: 02/21/2013] [Indexed: 10/26/2022]
Abstract
In a sample of Chuvashians (803 males and 738 females) we evaluated the mean values of index finger to ring finger (2D:4D) ratio, the contributions of phalanges and metacarpals to the 2D:4D ratio, and the symmetry between right and left 2D:4D ratios. Age, sex, anthropometric data and radiographs of both hands were collected. Each hand was visually classified on a radiograph as either Type 1 - index finger was longer than ring finger; Type 2 - equal; or Type 3 - index shorter than the ring finger. The following measurements (1) from the mid-point of the base of the proximal phalanx to the mid-point of the tip of the distal phalanx; and (2) from the mid-point of the base to the mid-point of the tip of the metacarpal were obtained from the index and ring fingers. Visual classification was significantly associated with the measured 2D:4D length ratio. Women had a higher prevalence of Type 1 and Type 2, but lower prevalence of Type 3 ratio in both hands. Men had smaller measured 2D:4D phalangeal, metacarpal and ray (combined) ratios than women. Symmetry between the right and left hand measured 2D:4D ratios were significant in phalangeal (r=0.657, p<0.001), metacarpal (r=0.638, p<0.001), ray (r=0.682, p<0.001) ratios and visual classification types (contingency coefficient=0.559, p<0.001). No sex dimorphism was found between the right and left hands. Correlations between age and visual classification were significant on both sides before and after adjustment for sex. This result is probably a sign of a secular trend in the Chuvashian sample and the study should be replicated in other samples.
Collapse
Affiliation(s)
- L Kalichman
- Department of Physical Therapy, Recanati School for Community Health Professions, Faculty of Health Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105, Israel.
| | | | | | | |
Collapse
|
35
|
Sigurjonsdottir K, Bjorgulfsson TM, Aspelund T, Eiriksdottir G, Sigurdsson S, Ingvarsson T, Harris TB, Launer L, Gudnason V, Jonsson H. Type 3 finger length pattern is associated with total knee replacements due to osteoarthritis but not with hip replacements or hand osteoarthritis in the elderly: the AGES-Reykjavik study. BMC Musculoskelet Disord 2013; 14:112. [PMID: 23530906 PMCID: PMC3626925 DOI: 10.1186/1471-2474-14-112] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 03/13/2013] [Indexed: 11/10/2022] Open
Abstract
Background Recent case–control studies have shown an association between type 3 finger length pattern (longer ring finger than index finger) and knee osteoarthritis. This large cross-sectional study tests the hypothesis that the type 3 pattern is associated with total joint replacements due to osteoarthritis in a large population based study. Methods Finger length ratios were assessed visually on 5170 hand photographs (2975 females, 2195 males, mean age 76). In this population-based multidisciplinary study of aging in Reykjavik, Iceland, the prevalence of osteoarthritis associated total knee replacements was 223(4.3%) and total hip replacements 316(6.1%). We then performed a binary logistic regression analysis for total knee replacements and total hip replacements, including finger length patterns, osteoarthritis at other sites and other variables with possible association to osteoarthritis such as age, BMI and bone mineral density of the spine. Results The prevalence of the type 3 pattern was 50% (43% in females, 58% in males). The regression analysis revealed an odds ratio for total knee replacements of 1.65 (1.24-2.2) p = 0.0007, in the type 3 finger pattern group, similar in both genders. This association was independent of the associations we have previously reported between total knee replacements and BMI and the presence of hand osteoarthritis. No association was seen between finger length patterns and total hip replacements. Conclusion Finger length patterns read from digital photographs in this large study confirm previous radiographic observations with significant associations between the type 3 pattern and total knee replacements but not total hip replacements in both genders in this elderly group.
Collapse
|
36
|
Peeters MW, Claessens AL. Digit ratio (2D:4D) and competition level in world-class female gymnasts. J Sports Sci 2013; 31:1302-11. [PMID: 23506462 DOI: 10.1080/02640414.2013.779741] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this study the relationship between the digit ratio (2D:4D) and artistic gymnastics performance and competition level was investigated in a sample of Caucasian world-class female gymnasts (n = 145). The sample was divided into three competition events (compulsories, free work, final score). Within each event three performance groups (lowest, middle, and highest) were based on the competition scores gathered at the World Championships at Rotterdam, the Netherlands, in 1987. Lengths of the digits were measured on X-rays of the left hand. Several anthropometric dimensions were measured and from those measurements an androgyny index (Bayer & Bayley) and somatotype components (endomorphy, mesomorphy, ectomorphy) were calculated. Although significant differences in some anthropometric characteristics between the performance level groups within each competition event were observed, no significant differences in the 2D:4D ratios were found between the performance level groups, varying from 0.918 ± 0.020 to 0.924 ± 0.020. Also, no significant correlations were observed between the 2D:4D ratio and anthropometric, androgyny, and somatotype characteristics, r varying from r = -0.11 to r = +0.12. It can be concluded that in this sample the 2D:4D digit ratio, unlike other anthropometric characteristics, is not a discriminating factor for the performance in artistic gymnastics performance on a world-class level.
Collapse
|
37
|
Jain M, Dhall U, Pandey S, Jain S. Second to Fourth Digit Ratio(2D:4D) in North-West Indians: Sexual Dimorphism. J ANAT SOC INDIA 2012. [DOI: 10.1016/s0003-2778(12)80038-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
38
|
|
39
|
Vaillancourt KL, Dinsdale NL, Hurd PL. Estrogen receptor 1 promoter polymorphism and digit ratio in men. Am J Hum Biol 2012; 24:682-9. [DOI: 10.1002/ajhb.22297] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 05/10/2012] [Accepted: 05/22/2012] [Indexed: 11/06/2022] Open
Affiliation(s)
| | - Natalie L. Dinsdale
- Department of Psychology, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
- Current Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Peter L. Hurd
- Department of Psychology, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| |
Collapse
|
40
|
Peeters MW, Claessens AL. The left hand second to fourth digit ratio (2D:4D) does not discriminate world-class female gymnasts from age matched sedentary girls. PLoS One 2012; 7:e40270. [PMID: 22768268 PMCID: PMC3386956 DOI: 10.1371/journal.pone.0040270] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 06/04/2012] [Indexed: 11/18/2022] Open
Abstract
Introduction The second to fourth-digit-ratio (2D:4D), a putative marker of prenatal androgen action and a sexually dimorphic trait, has been suggested to be related with sports performance, although results are not univocal. If this relation exists, it is most likely to be detected by comparing extreme groups on the continuum of sports performance. Methods In this study the 2D:4D ratio of world-class elite female artistic gymnasts (n = 129), competing at the 1987 Rotterdam World-Championships was compared to the 2D:4D ratio of sedentary age-matched sedentary girls (n = 129), alongside with other anthropometric characteristics including other sexually dimorphic traits such as an androgyny index (Bayer & Bayley) and Heath-Carter somatotype components (endomorphy, mesomorphy, ectomorphy) using AN(C)OVA. 2D:4D was measured on X-rays of the left hand. Results Left hand 2D:4D digit ratio in world class elite female gymnasts (0.921±0.020) did not differ significantly from 2D:4D in age-matched sedentary girls (0.924±0.018), either with or without inclusion of potentially confounding covariates such as skeletal age, height, weight, somatotype components or androgyny index. Height (161.9±6.4 cm vs 155.4±6.6 cm p<0.01), weight (53.9±7.6 kg vs 46.2 6.3 kg p<0.01), BMI (20.51±2.41 kg/m2 vs 19.05±1.56 kg/m2), skeletal age (15.2±1.1 y vs 14.5±1.2 y p>0.01), somatotype components (4.0/3.0/2.9 vs 1.7/3.7/3.2 for endomorphy (p<0.01), mesomorphy (p<0.01) and ectomorphy (p<0.05) respectively) all differed significantly between sedentary girls and elite gymnasts. As expressed by the androgyny index, gymnasts have, on average, broader shoulders relative to their hips, compared to the reference sample. Correlations between the 2D:4D ratio and chronological age, skeletal age, and the anthropometric characteristics are low and not significant. Conclusion Although other anthropometric characteristics of sexual dimorphism were significantly different between the two samples, the present study cannot discriminate sedentary girls from world-class female gymnasts by means of the left hand 2D:4D ratio.
Collapse
|
41
|
Hiraishi K, Sasaki S, Shikishima C, Ando J. The second to fourth digit ratio (2D:4D) in a Japanese twin sample: heritability, prenatal hormone transfer, and association with sexual orientation. ARCHIVES OF SEXUAL BEHAVIOR 2012; 41:711-24. [PMID: 22270254 DOI: 10.1007/s10508-011-9889-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 09/10/2011] [Accepted: 11/27/2011] [Indexed: 05/12/2023]
Abstract
The second to fourth digit ratio has been argued to reflect prenatal hormonal influences and is reportedly associated with various psychological and behavioral traits, such as sexual orientation, cognitive abilities, and personality. We examined genetic and environmental influences on the second to fourth digit ratio (2D:4D) using a Japanese twin sample (N=300). The genetic analysis showed substantial additive genetic influences for both right and left hand 2D:4D. The rest of the variance was explained mainly by environmental influences not shared within twin pairs. These findings were, in general, in accordance with preceding studies with primarily Caucasian twin samples. The bivariate genetic analysis revealed that the additive genetic influences were largely shared between the right and left hand, while the non-shared environmental influences were largely unique to each hand. Results from a comparison of opposite-sex and same-sex twins were not significant, although they were in the predicted direction according to the prenatal hormone transfer hypothesis. Female monozygotic twin pairs discordant in sexual orientation showed significant within-pair differences in left hand 2D:4D, where non-heterosexual twins had lower (more masculinized) 2D:4D. In addition, we found that non-heterosexual male MZ twins had larger (more feminized) 2D:4D than their heterosexual co-twins. These results suggest the existence of non-shared environmental influences that affect both 2D:4D and sexual orientation.
Collapse
Affiliation(s)
- Kai Hiraishi
- Kokoro Research Center, Kyoto University, Yoshida-shimoadachi-cho 46-1, Sakyo, Kyoto, 606-8501, Japan.
| | | | | | | |
Collapse
|
42
|
Aggression, digit ratio, and variation in the androgen receptor, serotonin transporter, and dopamine D4 receptor genes in African foragers: the Hadza. Behav Genet 2012; 42:647-62. [PMID: 22392544 DOI: 10.1007/s10519-012-9533-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 02/15/2012] [Indexed: 02/07/2023]
Abstract
The role of genes in the expression of aggression and masculinity traits in humans has been a focus of recent behavioral genetic studies. This is the first study on the variation in aggression, the digit ratio (the ratio between the second and the fourth digits, 2D:4D), the directional asymmetry in 2D:4D (D(R-L)) and polymorphisms of the AR, DRD4, and 5-HTTL genes in simple hunter-gatherers, namely the Hadza of Tanzania (142 adult men). The distribution of AR, DRD4E3, and 5-HTTLPR genotypes and allele frequencies in Hadza was compared to other African populations on which the data were available. Hadza and Ariaal differed significantly in the distributions of frequencies of AR alleles with different numbers of CAG repeats. Hadza population was similar to other African populations in the distribution of allelic frequencies of the DRD4E3 locus, and to Afro-Americans in the distribution of allelic types of the 5-HTTLPR locus. We found no influence of AR gene on the right hand 2D:4D ratio, D(R-L), and any of aggression subscales of the Buss-Perry Aggression Questionnaire (AQ). Although, a weak positive correlation between CAG repeats and the left hand 2D:4D was found. The multiple regression analysis with digit ratios, D(R-L) and aggression subscales of AQ as dependent variables and the three gene candidates (AR, DRD4E3, and 5-HTTLPR) as independent variables revealed the following: men with lower number of CAG repeats had significantly lower left hand 2D:4D ratio; men with higher numbers of 48-bp unit copies in exon 3 of a VNTR polymorphism in the DRD4 gene had significantly lower digit ratios on both hands; no effect of the 5-HTTLPR gene on either the digit ratio or aggressive behavior. These findings demonstrate the complexity of gene effects on digit ratios and aggression and call for simultaneous analysis of more candidate genes. It is noteworthy that these results were obtained for a human population that is still practicing foraging and has been subjected to a high selective pressure due to harsh environments and practically has no access to modern medical care. Hadza are highly egalitarian, and their culture does not favor persons with a dominant or aggressive behavior. It is still to be found to what extent the relationships observed in this study are similar to those in other human populations.
Collapse
|
43
|
Medland SE, Loehlin JC. Multivariate Genetic Analyses of the 2D:4D Ratio: Examining the Effects of Hand and Measurement Technique in Data from 757 Twin Families. Twin Res Hum Genet 2012; 11:335-41. [DOI: 10.1375/twin.11.3.335] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractThe ratio of the lengths of the second to fourth digits of the hand (2D:4D) is a sexually dimorphic trait that has been proposed as a measure of prenatal testosterone exposure and a putative correlate of a variety of later behavioral and physiological outcomes including personality, fitness and sexual orientation. We present analyses of 2D:4D ratios collected from twins (1413 individuals) and their nontwin siblings (328 individuals) from 757 families. In this sample 2D:4D was measured from photocopies using digital calipers, and for a subset of participants, computer-aided measurement. Multivariate modeling of the left- and right-hand measurements revealed significant genetic and environmental covariation between hands. The two methods yielded very similar results, and the majority of variance was explained by factors shared by both measurement methods. Neither common environmental nor dominant genetic effects were found, and the covariation between siblings could be accounted for by additive genetic effects accounting for 80% and 71% of the variance for the left and right hands, respectively. There was no evidence of sex differences in the total variance, nor in the magnitude or source of genetic and environmental influences, suggesting that X-linked effects (such as the previously identified association with the Androgen receptor) are likely to be small. However, there were also nonshared environmental effects specific to each hand, which, in addition to measurement error, may in part explain why some studies within in the literature find effects for the 2D:4D ratio of one hand but not the other.
Collapse
|
44
|
Roberts SC, Kralevich A, Ferdenzi C, Saxton TK, Jones BC, DeBruine LM, Little AC, Havlicek J. Body odor quality predicts behavioral attractiveness in humans. ARCHIVES OF SEXUAL BEHAVIOR 2011; 40:1111-1117. [PMID: 21879430 DOI: 10.1007/s10508-011-9803-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Growing effort is being made to understand how different attractive physical traits co-vary within individuals, partly because this might indicate an underlying index of genetic quality. In humans, attention has focused on potential markers of quality such as facial attractiveness, axillary odor quality, the second-to-fourth digit (2D:4D) ratio and body mass index (BMI). Here we extend this approach to include visually-assessed kinesic cues (nonverbal behavior linked to movement) which are statistically independent of structural physical traits. The utility of such kinesic cues in mate assessment is controversial, particularly during everyday conversational contexts, as they could be unreliable and susceptible to deception. However, we show here that the attractiveness of nonverbal behavior, in 20 male participants, is predicted by perceived quality of their axillary body odor. This finding indicates covariation between two desirable traits in different sensory modalities. Depending on two different rating contexts (either a simple attractiveness rating or a rating for long-term partners by 10 female raters not using hormonal contraception), we also found significant relationships between perceived attractiveness of nonverbal behavior and BMI, and between axillary odor ratings and 2D:4D ratio. Axillary odor pleasantness was the single attribute that consistently predicted attractiveness of nonverbal behavior. Our results demonstrate that nonverbal kinesic cues could reliably reveal mate quality, at least in males, and could corroborate and contribute to mate assessment based on other physical traits.
Collapse
Affiliation(s)
- S Craig Roberts
- School of Biological Sciences, University of Liverpool, Liverpool, UK.
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Lenz B, Müller CP, Stoessel C, Sperling W, Biermann T, Hillemacher T, Bleich S, Kornhuber J. Sex hormone activity in alcohol addiction: integrating organizational and activational effects. Prog Neurobiol 2011; 96:136-63. [PMID: 22115850 DOI: 10.1016/j.pneurobio.2011.11.001] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2011] [Revised: 11/03/2011] [Accepted: 11/08/2011] [Indexed: 01/06/2023]
Abstract
There are well-known sex differences in the epidemiology and etiopathology of alcohol dependence. Male gender is a crucial risk factor for the onset of alcohol addiction. A directly modifying role of testosterone in alcohol addiction-related behavior is well established. Sex hormones exert both permanent (organizational) and transient (activational) effects on the human brain. The sensitive period for these effects lasts throughout life. In this article, we present a novel early sex hormone activity model of alcohol addiction. We propose that early exposure to sex hormones triggers structural (organizational) neuroadaptations. These neuroadaptations affect cellular and behavioral responses to adult sex hormones, sensitize the brain's reward system to the reinforcing properties of alcohol and modulate alcohol addictive behavior later in life. This review outlines clinical findings related to the early sex hormone activity model of alcohol addiction (handedness, the second-to-fourth-finger length ratio, and the androgen receptor and aromatase) and includes clinical and preclinical literature regarding the activational effects of sex hormones in alcohol drinking behavior. Furthermore, we discuss the role of the hypothalamic-pituitary-adrenal and -gonadal axes and the opioid system in mediating the relationship between sex hormone activity and alcohol dependence. We conclude that a combination of exposure to sex hormones in utero and during early development contributes to the risk of alcohol addiction later in life. The early sex hormone activity model of alcohol addiction may prove to be a valuable tool in the development of preventive and therapeutic strategies.
Collapse
Affiliation(s)
- Bernd Lenz
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-University of Erlangen-Nuremberg, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Khaĭrullin R. Segmental 2:4 digit ratio. Unilateral, bilateral and hand-type differences in men. HOMO-JOURNAL OF COMPARATIVE HUMAN BIOLOGY 2011; 62:478-86. [PMID: 22024126 DOI: 10.1016/j.jchb.2011.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 09/26/2011] [Indexed: 11/18/2022]
Abstract
Most studies of the 2:4 digit ratio (DR) of the human hand have analyzed its possibilities for use as an indicator of the functional, psychological, and, with rare exception, morphological features of the body. Each of the functional flexor segments (each phalanx) contributes to the common variability of the total digital length. The aim of this study was to determine patterns in the relationships between each segmental digit ratio (SDR) and the overall 2:4 DR. We studied the variability of the SDRs in comparison with the general 2:4 DR of 202 young males aged 16-21 years. The length of the functional segments of the digits was measured between the flexor skin furrows on the palmar surface. The change in the SDR means that values can be ranked as follows: proximal SDR (SDR-P)>DR>distal SDR (SDR-D)>medial SDR (SDR-M). Bilateral differences are inherent in the segmental SDR-P. Most quantitative regularities inherent in the total 2:4 DR are also intrinsic to the 2:4 DR of the distal segment of the digit; in particular, this phenomenon is displayed in hands of the ulnar (male) type. Overall, the values of the distal rather than the other functional flexor segments of the second and fourth digits are similar in magnitude to the general 2:4 DR. At the same time, the greatest correlation and hence, the largest contribution to the total variability in the general DR is from the variability of the SDR-P values. Our data demonstrate the importance of various digit segment sizes in determining their overall length and the derivative ratios.
Collapse
Affiliation(s)
- Radik Khaĭrullin
- Department of Human Anatomy, Medical Faculty of Ulyanovsk State University, Ulyanovsk 432000, Russia.
| |
Collapse
|
47
|
Ruuskanen S, Helle S, Ahola M, Adamczyck F, Möstl E, Laaksonen T. Digit ratios have poor indicator value in a wild bird population. Behav Ecol Sociobiol 2011; 65:983-994. [PMID: 21625648 PMCID: PMC3078308 DOI: 10.1007/s00265-010-1099-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 10/25/2010] [Accepted: 10/25/2010] [Indexed: 11/28/2022]
Abstract
Early androgen exposure is known to have long-lasting effects on phenotype, behaviour and even fitness, but difficulties in measuring the exposure hinders the study of its importance in evolutionary context. Digit ratios have been highlighted as a potential easy-to-measure indicator of early steroid exposure, as they have been suggested to reflect steroid, mainly testosterone levels during prenatal development. However, evidence for digit ratios reflecting early steroid levels is weak, as experimental studies, especially in wild populations, are scarce. We studied the association between maternally derived yolk androgens and digit ratios (2D:4D, 2D:3D and 3D:4D) using both correlative data and a rather high level of experimental elevation of yolk androgens in a passerine bird, the pied flycatcher (Ficedula hypoleuca). We also examined whether digit ratios have indicator value in an evolutionary context by studying correlations between digit ratios and reproductive traits, secondary sexual traits and exploratory behaviour. We did not find any association between digit ratios and yolk androgen level either in correlative or experimental data. Digit ratios were neither related to any of the reproductive and secondary sexual traits or exploratory behaviour measured. There was, however, a sex difference in 2D:3D and 3D:4D of adult birds (due to second and fourth digits being shorter in females), which was not apparent in fledglings or captivity-raised juveniles. This suggests that either the sex difference may develop as late as during the sexual maturation for breeding. These results indicate that, in this species, digit ratios are not reliable markers of maternally derived yolk androgen exposure and that they bear little relevance as correlates of the adaptive traits we measured.
Collapse
Affiliation(s)
- Suvi Ruuskanen
- Section of Ecology, Department of Biology, University of Turku, Turku, Finland
| | - Samuli Helle
- Section of Ecology, Department of Biology, University of Turku, Turku, Finland
| | - Markus Ahola
- Section of Ecology, Department of Biology, University of Turku, Turku, Finland
| | - Freya Adamczyck
- Department of Animal Population Biology, Netherlands Institute of Ecology (NIOO-KNAW), Heteren, The Netherlands
| | - Erich Möstl
- University of Veterinary Medicine, Vienna, Austria
| | - Toni Laaksonen
- Section of Ecology, Department of Biology, University of Turku, Turku, Finland
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| |
Collapse
|
48
|
Kyriakidis I, Papaioannidou P, Pantelidou V, Kalles V, Gemitzis K. Digit ratios and relation to myocardial infarction in Greek men and women. ACTA ACUST UNITED AC 2011; 7:628-36. [PMID: 21195362 DOI: 10.1016/j.genm.2010.11.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2010] [Indexed: 10/18/2022]
Abstract
BACKGROUND Digit ratios, such as the second to fourth digit ratio (2D:4D), are biometric markers that are influenced by estrogen and testosterone concentrations in utero and are determined genetically by HOX genes (homeodomain-containing homeotic genes). Sex steroids also play a crucial role in the occurrence of myocardial infarction (MI), which is considered to be gender dependent and related to testosterone. Additionally, first-trimester exposure to excess levels of estrogens and progesterone has been linked to cardiovascular anomalies. OBJECTIVE The aim of this work was to study digit ratios in a Greek population and assess their clinical importance as markers of predisposition to MI. METHODS Two samples were used: a group of Greek men and women hospitalized with MI, and a control group of healthy Greek men and women of the same age. Finger lengths were measured twice for both hands using electronic calipers. In the results, digits were designated as 2D (second digit), 3D (third digit), 4D (fourth digit), and 5D (fifth digit). RESULTS A total of 50 Greek men and 50 Greek women with MI were recruited (mean [SD] age, 69.3 [11.2] years for men; 69.7 [11.0] years for women). The control group consisted of 40 healthy Greek men and 40 healthy Greek women (mean age, 68.0 [11.8] years for men; 66.8 [10.7] years for women). In the control group, 2D:4D, 2D:3D, and 2D:5D ratios were significantly higher in women than in men (2D:4D: right hand, P < 0.001; left hand, P = 0.002; 2D:3D: right hand, P < 0.001; left hand, P = 0.003; 2D:5D: right hand, P < 0.001; left hand, P < 0.05). The mean values of 2D:4D ratios appeared to increase in the following order: healthy men < men with MI < healthy women < women with MI, although this difference was not statistically significant. In men with MI, 2D:4D and 3D:4D ratios were significantly higher than the respective ratios in healthy men (2D:4D: right hand, P = 0.001; left hand, P < 0.05; 3D:4D: right hand, P < 0.05; left hand, P = 0.001), but no significant differences were observed in the ratios between women with MI and healthy women. CONCLUSIONS Digit ratios that include ring-finger length (ie, 4D) may be useful biomarkers for predisposition to MI in Greek men, but not in Greek women. Sexual dimorphism of digit ratios was present in both groups and was independent of the individuals' health status.
Collapse
Affiliation(s)
- Ioannis Kyriakidis
- Department of Pharmacology, Aristotle University of Thessaloniki, Greece
| | | | | | | | | |
Collapse
|
49
|
Rahman AA, Lophatananon A, Stewart-Brown S, Harriss D, Anderson J, Parker T, Easton D, Kote-Jarai Z, Pocock R, Dearnaley D, Guy M, O'Brien L, Wilkinson RA, Hall AL, Sawyer E, Page E, Liu JF, Eeles RA, Muir K. Hand pattern indicates prostate cancer risk. Br J Cancer 2010; 104:175-7. [PMID: 21119657 PMCID: PMC3039824 DOI: 10.1038/sj.bjc.6605986] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND The ratio of digit lengths is fixed in utero, and may be a proxy indicator for prenatal testosterone levels. METHODS We analysed the right-hand pattern and prostate cancer risk in 1524 prostate cancer cases and 3044 population-based controls. RESULTS Compared with index finger shorter than ring finger (low 2D : 4D), men with index finger longer than ring finger (high 2D : 4D) showed a negative association, suggesting a protective effect with a 33% risk reduction (odds ratio (OR) 0.67, 95% confidence interval (CI) 0.57-0.80). Risk reduction was even greater (87%) in age group <60 (OR 0.13, 95% CI 0.09-0.21). CONCLUSION Pattern of finger lengths may be a simple marker of prostate cancer risk, with length of 2D greater than 4D suggestive of lower risk.
Collapse
Affiliation(s)
- A A Rahman
- Division of Epidemiology and Public Health, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Hurd PL, Vaillancourt KL, Dinsdale NL. Aggression, digit ratio and variation in androgen receptor and monoamine oxidase a genes in men. Behav Genet 2010; 41:543-56. [PMID: 20967566 DOI: 10.1007/s10519-010-9404-7] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 10/05/2010] [Indexed: 12/28/2022]
Abstract
Variation in prenatal exposure to androgens is thought to be responsible for some of the individual differences in aggressive behavior among adults. A putative indicator of prenatal testosterone exposure, 2D:4D (the index to ring finger length) ratios have shown a weak correlation with aggression. Variation in sensitivity of the androgen receptor, resulting from polymorphism in the AR gene, is also thought to influence the relative expression of sexually dimorphic traits within each sex, including aggressive behavior and 2D:4D. Here we examine variation in aggression, 2D:4D, and polymorphism in the AR and MAO-A genes in a sample of 188 men. We find no evidence of AR gene influence on right hand 2D:4D, and a weak trend towards more feminine-typical left hand 2D:4D in men with more sensitive androgen receptors. Men with more sensitive androgen receptors tended to score lower on many of the subscales of the Aggression Questionnaire and Indirect Aggression Questionnaire. We found no influence of MAO-A allele on either digit ratio or aggressive behavior. We conclude that more masculine-typical 2D:4D does not reflect greater sensitivity to testosterone through variation in this locus on the AR gene, and that AR alleles conferring greater sensitivity to testosterone are associated with lower, not higher propensity to aggression.
Collapse
Affiliation(s)
- Peter L Hurd
- Department of Psychology, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
| | | | | |
Collapse
|