1
|
Hendriks O, Wei Y, Warrier V, Richards G. Autistic Traits, Empathizing-Systemizing, and Gender Diversity. ARCHIVES OF SEXUAL BEHAVIOR 2022; 51:2077-2089. [PMID: 35467170 PMCID: PMC9192400 DOI: 10.1007/s10508-021-02251-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 05/27/2023]
Abstract
Previous research indicates a link between autism and transgender and gender-diverse identities, though the association is not yet fully understood. The current study examined autistic traits (Autism Spectrum Quotient [AQ]), empathizing (Empathizing Quotient-Short [EQ-S]), and systemizing (Systemizing Quotient-Short [SQ-S]) in a sample of 89 adults and aimed to test whether gender-diverse individuals exhibit cognitive profiles consistent with predictions derived from the Extreme Male Brain (EMB) theory. As most research has considered only cisgender people, we recruited a more diverse sample by contacting > 200 UK LGBTQ+ organizations and posting on social media. A range of non-cisgender identities (e.g., transgender male, transgender female, non-binary, genderqueer, transmasculine) and non-heterosexual orientations (e.g., bisexual) were represented, and participants were categorized into one of four groups: (1) assigned female at birth but does not identify as female (transgender AFAB) (n = 32), (2) cisgender female (n = 21), (3) assigned male at birth but does not identify as male (transgender AMAB) (n = 18), and (4) cisgender male (n = 18). After controlling for age and autism diagnostic status, transgender AFAB participants had marginally higher AQ scores, and significantly higher SQ-S and systemizing-relative-to-empathizing (D) scores, compared with the cisgender female group. No such differences were detected between the transgender AMAB and cisgender male groups. Our findings are broadly in line with predictions derived from the EMB theory, though as no transgender AFAB participants reported being heterosexual, it was not possible to determine whether these effects relate specifically to gender identity, to sexual orientation, or to both.
Collapse
Affiliation(s)
- Olivia Hendriks
- School of Psychology, Faculty of Medical Sciences, Newcastle University, Dame Margaret Barbour Building, Wallace Street, Newcastle upon Tyne, NE2 4DR, UK
| | - Yimeng Wei
- School of Psychology, Faculty of Medical Sciences, Newcastle University, Dame Margaret Barbour Building, Wallace Street, Newcastle upon Tyne, NE2 4DR, UK
| | - Varun Warrier
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18b Trumpington Road, Cambridge, UK
| | - Gareth Richards
- School of Psychology, Faculty of Medical Sciences, Newcastle University, Dame Margaret Barbour Building, Wallace Street, Newcastle upon Tyne, NE2 4DR, UK.
- Autism Research Centre, Department of Psychiatry, University of Cambridge, Douglas House, 18b Trumpington Road, Cambridge, UK.
| |
Collapse
|
2
|
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
|
3
|
Siegmann EM, Müller T, Dziadeck I, Mühle C, Lenz B, Kornhuber J. Digit ratio (2D:4D) and transgender identity: new original data and a meta-analysis. Sci Rep 2020; 10:19326. [PMID: 33168880 PMCID: PMC7653965 DOI: 10.1038/s41598-020-72486-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 09/02/2020] [Indexed: 01/20/2023] Open
Abstract
Previously reported associations between second-to-fourth digit length ratio (2D:4D), a proxy for prenatal androgen load, and transgender identity have been inconsistent. The objectives of the present study were to provide additional original data and an updated meta-analysis concerning this association. In a study of 464 participants, we compared the 2D:4D of transgender individuals with age- and sex-matched controls. Patients were recruited at a specialized psychiatrist's medical office, whereas controls were hired via flyers, advertisements, and as convenience sample. A random-effects meta-analysis of the literature (17 samples, n = 3674) also quantifies the overall magnitude of the difference in 2D:4D between transgender individuals and controls. In our study providing new original data, we found a significantly higher (i.e. feminized) left-hand 2D:4D in the male-to-female transgender (MtF) identity [mean age: 32.3 (18; 61)] than in the male control group [mean age: 34.5 (18; 65)] with a Cohen's d = 0.271. Concordantly, the meta-analytic results suggest a significant difference in 2D:4D among MtF individuals compared to male controls [g = 0.153; 95% CI (0.063; 0.243)], which was even more pronounced when individuals had been diagnosed by a clinician instead of self-identified as transgender [g = 0.193; 95% CI (0.086; 0.300)]. In both studies, no significant results were revealed for female-to-male transgender individuals [mean age: 26.1 (18; 53)] versus female controls [mean age: 27.2 (18; 55)]. This original investigation and the updated meta-analysis clarify the association between transgender identity and 2D:4D indicating the influence of prenatal androgen on the development of gender identity in subjects born as males.
Collapse
Affiliation(s)
- Eva-Maria Siegmann
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany.
| | - Tobias Müller
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
- Psychiatric Practice, Treibberg 5, 90403, Nuremberg, Germany
| | - Isabelle Dziadeck
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Christiane Mühle
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| | - Bernd Lenz
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
- Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health (CIMH), Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Johannes Kornhuber
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Schwabachanlage 6, 91054, Erlangen, Germany
| |
Collapse
|