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Lyu J, Cui J, Yang F, Gao X, Cui Z, Zhou X. The interconnection of orthographic, phonetic, and semantic skills with arithmetic fluency. PSYCHOLOGICAL RESEARCH 2024:10.1007/s00426-024-02005-z. [PMID: 39034343 DOI: 10.1007/s00426-024-02005-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 07/05/2024] [Indexed: 07/23/2024]
Abstract
Arithmetic fluency is considered considers highly rely on language processing, encompassing essential skills. However, the independent predictive power of phonetic, semantic, or orthographic skills in relation to arithmetic fluency remains an unresolved query. This study introduces the common component hypothesis to elucidate the inconsistent findings in previous research. The hypothesis posits that significant correlations between language and mathematics hinge on whether the language and mathematics utilized in a given task share a common component. According to this hypothesis, processing skills for each of the three fundamental language elements (i.e., phonetic, semantic, orthographic) should correlate with arithmetic fluency, as these elements are also integral to simple arithmetic processing. A cohort of one hundred and ninety-eight primary school students participated in the study, undertaking a battery of tests assessing general cognitive abilities, psycholinguistic elements, and arithmetic fluency. The results showed that orthographic, phonetic, and semantic abilities independently predicted arithmetic fluency, even after accounting for all other cognitive predictors. These findings substantiate the common component hypothesis, providing empirical support for explaining the association between language and mathematics. This evidence contributes to addressing the interplay between language and mathematics in educational contexts.
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Affiliation(s)
- Jing Lyu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institude for Brain Research, Faculty of Psychology, Beijing Normal University, Beijing, 100875, China
| | - Jiaxin Cui
- College of Education, Hebei Normal University, Shijiazhuang, Hebei, 050024, China
| | - Fan Yang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institude for Brain Research, Faculty of Psychology, Beijing Normal University, Beijing, 100875, China
- School of Education Science, Anhui Normal University, Wuhu, Anhui, China
| | - Xing Gao
- College of Education, Hebei Normal University, Shijiazhuang, Hebei, 050024, China
| | - Zhanling Cui
- College of Education, Hebei Normal University, Shijiazhuang, Hebei, 050024, China.
| | - Xinlin Zhou
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institude for Brain Research, Faculty of Psychology, Beijing Normal University, Beijing, 100875, China.
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Dutta S, Nie CW, Sarna A, Hari P, Sengupta P. Second to fourth digit ratio (2D:4D) as the 'anatomical marker' and reproductive 'hormonal fingerprint' in the occurrence dental plaque accumulation. Horm Mol Biol Clin Investig 2024; 45:41-47. [PMID: 38726654 DOI: 10.1515/hmbci-2023-0063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 04/29/2024] [Indexed: 06/27/2024]
Abstract
OBJECTIVES Digit ratio (2D:4D), as endocrine fingerprint, can indicate prenatal androgen exposure. It serves as an anatomical marker for various systemic diseases and a few studies relating it to oral health. The present study aims to evaluate the association between digit ratio and susceptibility to dental plaque formation. METHODS The study was conducted on young adults aged between 18 and 25 years. Digit ratio and reproductive hormones were measured; dental plaque score and gingival index (GI) were recorded. Data were analysed using the MedCalc. v.20. RESULTS Male and female participants were categorized into two groups based on their digit ratios being either above or below the calculated average (0.99 for females, 0.98 for males). Those with a digit ratio below the average had a significantly higher mean dental plaque score (p < 0.0001) than those with ratios at or above the average. However, there was no significant difference in the GI between the two groups. Reproductive hormone profiles varied significantly between the higher and lower digit ratio groups for both sexes. CONCLUSIONS Digit ratio may find potential to be used as an anatomical marker to identify the susceptibility to dental plaque build-up.
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Affiliation(s)
- Sulagna Dutta
- Basic Medical Sciences Department, College of Medicine, Ajman University, Ajman, UAE
| | - Chin Win Nie
- Faculty of Dentistry, 105956 MAHSA University , Jenjarom, Selangor, Malaysia
| | - Amrita Sarna
- Faculty of Dentistry, 105956 MAHSA University , Jenjarom, Selangor, Malaysia
| | - Padmini Hari
- Faculty of Dentistry, 105956 MAHSA University , Jenjarom, Selangor, Malaysia
| | - Pallav Sengupta
- Department of Biomedical Sciences, College of Medicine, Gulf Medical University, Ajman, UAE
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Butovskaya M, Adam Y, Batsevich V, Shackelford TK, Fink B. Associations between 2D:4D from direct and radiographic measurements with handgrip strength in young adult Tuvans. Early Hum Dev 2024; 193:106037. [PMID: 38743999 DOI: 10.1016/j.earlhumdev.2024.106037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/06/2024] [Accepted: 05/07/2024] [Indexed: 05/16/2024]
Abstract
BACKGROUND Digit ratio (2D:4D) - the relative lengths of the index and ring finger - is sexually dimorphic (male < female), possibly because of the sex-differentiated impact of prenatal androgenization on fetal development in the 1st trimester. The sex difference remains stable with age and has been reported in children, adolescents, and adults from industrialized and non-industrialized societies. Handgrip strength (HGS) also is sexually dimorphic (males > females) and correlates negatively with 2D:4D. AIMS To examine in a sample of young adult Tuvans from Siberia (Russian Federation): i) the association between 2D:4D measured directly from the palms with 2D:4D measured from radiographic images of the same individuals and ii) the associations between 2D:4D and HGS in Tuvan men and women. STUDY DESIGN AND SUBJECTS The study was cross-sectional. Participants were Tuvans (n = 185; 80 men; mean age = 21.02 years). 2D:4D was measured with a caliper from the ventral surface of the palm (both hands) and from radiographic images (left hand). HGS of both hands was measured with a digital hand dynamometer. Body height and weight were measured with an anthropometer and a body composition scale. RESULTS 2D:4D ratios and anthropometric measures (including HGS) were sexually dimorphic. Men had lower 2D:4D and higher HGS than women. Direct measures of 2D:4D correlated positively with 2D:4D measured from radiographs. Body mass index (BMI) was a significant predictor of HGS for both sexes. Male right 2D:4D and female right and left 2D:4D correlated negatively with HGS after controlling for the influence of BMI. There were no associations with radiographic measurements of 2D:4D. CONCLUSION Our findings provide evidence of sexual dimorphism in 2D:4D among young adult Tuvans. Together with previous research on Tuvan children and adolescents, these findings provide clear evidence of 2D:4D sexual dimorphism in pre- and postpubertal Tuvans. The small negative association between 2D:4D and HGS corresponds to similar reports across populations, suggesting that 2D:4D is a weak correlate of muscular fitness.
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Affiliation(s)
- Marina Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russian Federation; Russian State University for the Humanities, Moscow, Russian Federation; National Research University Higher School of Economics, Moscow, Russian Federation.
| | - Yulia Adam
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Valery Batsevich
- Anuchin Research Institute and Museum of Anthropology, Lomonosov Moscow State University, Moscow, Russian Federation
| | | | - Bernhard Fink
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria; Human Evolution and Archaeological Sciences (HEAS), University of Vienna, Vienna, Austria; Biosocial Science Information, Biedermannsdorf, Austria
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Sorokowski P, Kowal M. Relationship between the 2D:4D and prenatal testosterone, adult level testosterone, and testosterone change: Meta-analysis of 54 studies. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:20-38. [PMID: 37795916 DOI: 10.1002/ajpa.24852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/29/2023] [Accepted: 09/12/2023] [Indexed: 10/06/2023]
Abstract
The ratio between the hands' second to the fourth finger (2D:4D) is commonly hypothesized to result from prenatal testosterone. The 2D:4D has also been hypothesized to relate to adult-level testosterone and, more recently, to the testosterone response to a challenging situation. In the present work, we tested these core assumptions. Drawing from, in total, 54 studies and 8077 participants, we investigated whether the 2D:4D is related to adult level testosterone (44 studies), testosterone change (6 studies), and prenatal testosterone (10 studies). We found no evidence of the relationship between the above testosterone types and digit ratios. Furthermore, there was no relationship between testosterone and the right and left 2D:4D, male and female 2D:4D, and the 2D:4D and testosterone measurement (i.e., measured in blood or saliva). However, we found some evidence that prenatal testosterone measured in amniotic fluid (but not cord blood) might be related to the digit ratios-further studies are necessary to validate this observation. In summary, considering the current state of knowledge, any conclusions drawn from the assumption of the digit ratios as the proxy for testosterone (prenatal, adult level, or testosterone change under a challenging situation) warrant great caution.
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Affiliation(s)
| | - Marta Kowal
- IDN Being Human Lab, University of Wrocław, Wrocław, Poland
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Butovskaya M, Adam Y, Batsevich V, Shackelford TK, Fink B. Direct and radiographic digit ratio (2D:4D) measurements of Tuvan children and adolescents from Southern Siberia: Sex differences and skeletal maturation. Early Hum Dev 2023; 184:105835. [PMID: 37517120 DOI: 10.1016/j.earlhumdev.2023.105835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/26/2023] [Accepted: 07/26/2023] [Indexed: 08/01/2023]
Abstract
BACKGROUND In Mongolian-origin ethnic groups digit ratio (2D:4D; a proxy for prenatal sex-steroids) is sexually dimorphic (males < females), as reported for other ethnicities. Most studies measured 2D:4D from soft tissue (directly from the digits, or indirectly from hand scans), or from radiographs. Evidence on the correspondence of 2D:4D measurements from soft tissue with measurements from radiographic images is scarce and has not been reported for a Mongolian-origin sample. In addition, previous research has not considered relationships between 2D:4D and measures of skeletal maturity. AIM To examine (i) associations between 2D:4D measured directly from the palms with those obtained from radiographic images of the same individuals in a sample of children and adolescents from the Tuvan population in Siberia (Russian Federation), and ii) associations between 2D:4D measurements with chronological and skeletal age. SUBJECTS AND METHODS Participants were Tuvan boys and girls aged 7 to 18 years. 2D:4D of the right and left hand was measured from soft tissue (directly from the palm) and compared with radiographic images (left hand only). In addition to finger length 2D:4D, we examined 2D:4D of the phalanges from measurements of radiographs. Skeletal age was assessed using the Tanner-Whitehouse method. RESULTS Sex differences (boys < girls) in measurements of 2D:4D from soft tissue and radiographs were found for total finger length and phalanges. In addition, 2D:4D measurements from radiographs correlated positively and significantly with those obtained from soft tissue. Sex predicted 2D:4D measurements from soft tissue and radiographs, but no effects of chronological/skeletal age and body height were detected. In girls (but not in boys), earlier skeletal maturity (relative to chronological age) was associated with higher 2D:4D in soft tissue measurements of both hands, radiographic 2D:4D, and 2D:4D of the proximal phalanges. CONCLUSION Consistent with reports from other ethnic groups, 2D:4D in young Tuvans was sexually dimorphic, with boys having lower 2D:4D than girls. For girls, higher 2D:4D was found for participants whose skeletal age was more advanced than chronological age. This finding was obtained from direct soft tissue and indirect radiographic measurements. Age and body height were not associated with 2D:4D, which suggests differences in hormone developmental trajectories for 2D:4D and height.
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Affiliation(s)
- Marina Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russian Federation; National Research University Higher School of Economics, Moscow, Russian Federation; Russian State University for the Humanities, Moscow, Russian Federation
| | - Yulia Adam
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russian Federation
| | - Valery Batsevich
- Anuchin Research Institute and Museum of Anthropology, Lomonosov Moscow State University, Moscow, Russian Federation
| | | | - Bernhard Fink
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria; Human Evolution and Archaeological Sciences (HEAS), University of Vienna, Vienna, Austria; Biosocial Science Information, Biedermannsdorf, Austria.
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Nobari H, Eken Ö, Prieto-González P, Oliveira R, Brito JP. Association between 2D:4D ratios and sprinting, change of direction ability, aerobic fitness, and cumulative workloads in elite youth soccer players. BMC Sports Sci Med Rehabil 2023; 15:45. [PMID: 36978178 PMCID: PMC10045863 DOI: 10.1186/s13102-023-00654-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/21/2023] [Indexed: 03/30/2023]
Abstract
BACKGROUND The aim of this study was two-fold: (i) to determine the correlation between 2D:4D, maximal oxygen uptake (VO2max), body fat percentage (BF%), maximum heart rate (HRmax), change of direction (COD), and accumulated acute and chronic workload variables; (ii) to verify if the length of the second digit divided by fourth digit (2D:4D) can explain fitness variables and accumulated training load. METHODS Twenty elite young football players (age: 13.26 ± 0.19 years; height: 165.8 ± 11.67 cm; body mass: 50.70 ± 7.56 kg; VO2max, 48.22 ± 2.29 ml.kg- 1.min- 1) participated in the present study. Anthropometric and body composition variables (e.g., height, body mass, sitting height, age, BF%, body mass index, right and left finger 2D:4D ratios) were measured. The following fitness tests were also conducted: 30 - 15 Intermittent Fitness Test (VO2max and HRmax), COD (5-0-5 agility test), and speed (10-30msprint test. HRmax and the training load were also measured and monitored using the Rate of Perceived Exertion during the 26 weeks. RESULTS There were associations between HRmax and VO2max, between 2D and 4D lengths and Left and Right hand ratios. Also, in AW with Right and Left 4D. The CW and de ACWR with the Right 4D. There were other associations between physical test variables and workload variables. CONCLUSIONS Under-14 soccer players with low right and left-hand 2D:4D ratios did not perform better in the selected fitness tests to assess VO2max, COD, or sprint ability. However, it cannot be ruled out that the absence of statistically significant results may be related to the small sample size and the maturational heterogeneity of the participants.
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Affiliation(s)
- Hadi Nobari
- Department of Exercise Physiology, Faculty of Educational Sciences and Psychology, University of Mohaghegh Ardabili, Ardabil, 56199-11367, Iran.
- Faculty of Sport Sciences, University of Extremadura, Cáceres, 10003, Spain.
| | - Özgür Eken
- Department of Physical Education and Sport Teaching, Inonu University, Malatya, Turkey
| | - Pablo Prieto-González
- Health and Physical Education Department, Prince Sultan University, Riyadh, 11586, Saudi Arabia
| | - Rafael Oliveira
- Sports Science School of Rio Maior-Polytechnic Institute of Santarém, Rio Maior, 2040-413, Portugal
- Research Center in Sport Sciences, Health Sciences and Human Development, Vila Real, 5001-801, Portugal
- Life Quality Research Centre, Rio Maior, 2040-413, Portugal
| | - João Paulo Brito
- Sports Science School of Rio Maior-Polytechnic Institute of Santarém, Rio Maior, 2040-413, Portugal
- Research Center in Sport Sciences, Health Sciences and Human Development, Vila Real, 5001-801, Portugal
- Life Quality Research Centre, Rio Maior, 2040-413, Portugal
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The effects of sex, nation, ethnicity, age and self-reported pubertal development on participant-measured right-left 2D:4D (Dr-l) in the BBC internet study. J Biosoc Sci 2023; 55:383-395. [PMID: 35088686 DOI: 10.1017/s0021932022000049] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Digit ratio (2D:4D) - a proxy for prenatal sex steroids - shows sex, nationality and ethnic differences and is linked to pubertal onset. It is unclear whether right-left 2D:4D (Dr-l) also correlates with prenatal sex steroids, as evidence of these differences has been less conclusive. The present study examined the effects of sex, nation, ethnicity, age and self-reported pubertal development (i.e. the rate of physical development and age at menarche [females] or first shave [males]) on Dr-l in a large online study (the BBC internet study). Digit lengths were self-measured in 201,865 adults (110,955 males) and the sample of nations included 41 countries. Participants reported the self-perceived rate of physical pubertal development on a five-point scale (from very slow to very fast) and provided information on the age at menarche or first shave. Adult (>17 years) males had lower Dr-l than females with weak effect size across 41 nations (males-females; d = -.065, p < .0001). There were sex and ethnicity effects on Dr-l across seven ethnic groups with males < females and lower Dr-l in Whites and Middle/Near Eastern participants compared to Asian, Black and Chinese respondents. Considering age effects, the authors focused on participants >12 years; there were stable sex differences and a weak positive effect of age on Dr-l. Dr-l showed a positive relationship with the rate of physical development and a negative relationship with age at menarche or first shave. Relationships were present in males and females with stronger effects in the latter. It is concluded that Dr-l shows a weak sex difference (males < females) independent of nation, ethnicity and age, and suggest that Dr-l is a proxy for prenatal sex steroids.
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Fang S, Zhou X. Form perception speed is critical for the relationship between non-verbal number sense and arithmetic fluency. INTELLIGENCE 2022. [DOI: 10.1016/j.intell.2022.101704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Pickering GJ, Anger N, Baird J, Dale G, Tattersall GJ. Use of crowdsourced images for determining 2D:4D and relationship to pro-environmental variables. Acta Ethol 2022; 25:165-178. [PMID: 36097527 PMCID: PMC9452876 DOI: 10.1007/s10211-022-00401-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/28/2022] [Accepted: 08/16/2022] [Indexed: 01/02/2023]
Abstract
The primary purpose of this study was to examine whether 2D:4D ratios (a putative measure of prenatal androgen exposure) could be determined using participant-submitted hand images. The secondary purpose was to examine whether 2D:4D ratio was associated with pro-environmental behaviors, attitudes, and empathy, given the recent literature linking sex to environmental attitudes and actions. Participants (N = 1065) were asked via an online survey to submit a clear photograph of their right hand, palm side up. Participants also completed a questionnaire to assess (a) demographics, (b) dispositional empathy, and (c) environmental attitudes and behavior. A 2D:4D ratio was calculated for each participant, and the quality of each image was classified as poor, moderate, or good. We then examined the reliability of the 2D:4D image measurements, and the relationship between 2D:4D and our environmental measures. 2D:4D ratios fell somewhat outside of previously reported ranges, but the measurements did show acceptable intra-rater consistency. Although we did not find a sex difference in 2D:4D, we did find a sex by ratio interaction for both empathy and the number of pro-environmental behaviors in which individuals had engaged. Specifically, as 2D:4D ratio increased, males reported lower empathy and less engagement in pro-environmental behaviors, whereas females reported more engagement in pro-environmental behaviors (but no differences in empathy). These findings were contrary to expectations, as we anticipated that greater digit ratios (i.e., feminized) would be associated with greater empathy and pro-environmental behaviors. Overall, the findings of this study present a preliminary examination of the utility of measuring digit ratio with online samples. Furthermore, our results provide information regarding the complex relationship between sex and pro-environmental behaviors.
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Affiliation(s)
- Gary J. Pickering
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1 Canada
- Psychology Department, Brock University, St. Catharines, Canada
- Environmental Sustainability Research Centre, Brock University, St. Catharines, Canada
- Sustainability Research Centre, University of the Sunshine Coast, Sippy Downs, Australia
| | - Nicholas Anger
- Centre for Digital Humanities, Brock University, St. Catharines, Canada
| | - Julia Baird
- Environmental Sustainability Research Centre, Brock University, St. Catharines, Canada
- Sustainability Research Centre, University of the Sunshine Coast, Sippy Downs, Australia
- Department of Geography and Tourism Studies, Brock University, St. Catharines, Canada
| | - Gillian Dale
- Environmental Sustainability Research Centre, Brock University, St. Catharines, Canada
| | - Glenn J. Tattersall
- Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON L2S 3A1 Canada
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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.
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Swift-Gallant A, Shirazi T, Puts DA, Breedlove SM. Evidence for Perinatal Steroid Influence on Human Sexual Orientation and Gendered Behavior. Cold Spring Harb Perspect Biol 2022; 14:a039123. [PMID: 34872968 PMCID: PMC9341466 DOI: 10.1101/cshperspect.a039123] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In laboratory animals, exposure to gonadal steroid hormones before and immediately after birth can exert permanent effects on many behaviors, particularly reproductive behaviors. The extent to which such effects occur in humans remains an open question, but several lines of evidence indicate that perinatal levels of both androgens and estrogens may affect adult human psychology and behavior, including sexual orientation and gender nonconformity. Some putative indicators of prenatal androgen exposure, including the ratio of the length of the index finger to that of the ring finger (2D:4D), have repeatedly indicated that lesbians, on average, were exposed to more prenatal androgens than straight women, suggesting that sufficient fetal androgen exposure predisposes a fetus to gynephilia (attraction to women) at maturity. The digit ratios of gay men do not differ from those of straight men, suggesting that prenatal androgen levels are not responsible for their androphilia (attraction to men). However, evidence that gay men who prefer an insertive anal sex role (ASR) have more masculine digit ratios than those preferring a receptive ASR suggests that early androgens influence some sexual preferences in men. Furthermore, digit ratios among gay men have been found to correlate with recalled childhood gender nonconformity (CGN). People with isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) offer further insight into the effects of perinatal gonadal steroid exposure. In people with IGD, gonadal hormone production is low or absent after the first trimester of gestation. However, because placental gonadotropins drive gonadal hormone secretion during the first trimester when genitalia sexually differentiate, individuals with IGD are unambiguously male or female at birth, consistent with their chromosomal and gonadal sex. Men with IGD report greater CGN, again suggesting that perinatal androgen exposure contributes to male-typical behavioral patterns in humans. Interestingly, women with IGD report less androphilia and more bisexuality than control women, suggesting that perinatal ovarian steroids in females typically augment androphilia in adulthood. Taken together, these findings indicate that the perinatal hormonal milieu influences human sexual orientation and gender conformity.
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Affiliation(s)
- Ashlyn Swift-Gallant
- Department of Psychology, Memorial University of Newfoundland, St. John's A1B 3X9, Newfoundland and Labrador
| | - Talia Shirazi
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - David A Puts
- Department of Anthropology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - S Marc Breedlove
- Neuroscience Program, Michigan State University, East Lansing, Michigan 48824, USA
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2D:4D digit ratio and its relationship to BMI, sporting choices and physiological predispositions among women. ANTHROPOLOGICAL REVIEW 2022. [DOI: 10.18778/1898-6773.85.2.07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 2D:4D digit ratio has been established as a biomarker of the level of exposure to prenatal sex hormones’ balancebetween prenatal testosterone (PT) and estrogenne levels. Higher 2D:4D indicates lower PT exposure and vice versa. Data suggests that PT exposure is linked to a risk-taking attitude and physical aggressiveness, both of which are requirements in contact sport. A possible correlation between 2D:4D and human body mass index has also been identified. The aim of the study was to examine the relation between 2D:4D ratio and choice of sport. It was assumed that female soccer players who choose a contact sport would have a lower 2D:4D ratio (thus experiencing higher exposure to PT) than female volleyball players (selecting non-contact sport). The analysis was also aimed at identifying whether a correlation between prenatal testosterone level and BMI exists. The participant sample consisted of 103 women – 36 volleyball players, 33 soccer players and a control group (N=34). Measurements were collected in 2019–2020. The results suggest that 2D:4D was significantly different in women practicing various sports (contact and non-contact sports). Women engaged in contact sports had lower 2D:4D than women engaged in non-contact sports, and vice versa (p<0.05). 2D:4D correlated positively with BMI and body weight – the higher the 2D:4D ratio, the higher the BMI and body weight (and vice versa) (p<0.05). Low 2D:4D (high PT exposure) may predict the choice of more risky, aggressive contact sports, and vice versa. High 2D:4D may predict a higher BMI and body weight, and vice versa.
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Cui J, Lv L, Du H, Cui Z, Zhou X. Language Ability Accounts for Ethnic Difference in Mathematics Achievement. Front Psychol 2022; 13:929719. [PMID: 35936256 PMCID: PMC9354024 DOI: 10.3389/fpsyg.2022.929719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 06/22/2022] [Indexed: 12/03/2022] Open
Abstract
The mathematics achievement of minority students has always been a focal point of educators in China. This study investigated the differences in mathematics achievement between Han and minority pupils to determine if there is any cognitive mechanism that can account for the discrepancy. We recruited 236 Han students and 272 minority students (including Uygur and Kazak) from the same primary schools. They were tested on mathematics achievement, language abilities, and general cognitive abilities. The results showed that Han pupils had better mathematics achievement scores and better Chinese language ability than minority students. After controlling for age, gender, and general cognitive abilities, there were still significant differences in mathematics achievement between Han and minority students. However, these differences disappeared after controlling for language ability. These results suggest that the relatively poor levels of mathematics achievement observed in minority students is related to poor Chinese language skills.
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Affiliation(s)
- Jiaxin Cui
- College of Education, Hebei Normal University, Shijiazhuang, China
- State Key Laboratory of Cognitive Neuroscience and Learning, Faculty of Psychology, Beijing Normal University, Beijing, China
| | - Liting Lv
- College of Education, Hebei Normal University, Shijiazhuang, China
| | - Huibo Du
- College of Education, Hebei Normal University, Shijiazhuang, China
| | - Zhanling Cui
- College of Education, Hebei Normal University, Shijiazhuang, China
| | - Xinlin Zhou
- State Key Laboratory of Cognitive Neuroscience and Learning, Faculty of Psychology, Beijing Normal University, Beijing, China
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14
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Rinella S, Massimino S, Sorbello A, Perciavalle V, Coco M. Cognitive Performances: The Role of Digit Ratio (D2:D4) With a Protective Factor for Anxiety. FRONTIERS IN NEUROERGONOMICS 2022; 3:870362. [PMID: 38235465 PMCID: PMC10790902 DOI: 10.3389/fnrgo.2022.870362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 03/02/2022] [Indexed: 01/19/2024]
Abstract
This study aimed to identify a possible correlation between the D2:D4 ratio and state and/or trait anxiety in adult healthy subjects and, if so, whether it exists any difference between men and women. In addition, we also wanted to observe whether there is a relationship between participants' age and state and/or trait anxiety. The research involved 125 subjects of both sexes, who were calculated the D2:D4 ratio and were administered the self-assessment questionnaire State-Trait Anxiety Inventory (STAI-Y). Results show that there are positive significant correlations between the D2:D4 ratio and score at state anxiety and trait anxiety, in the total sample. However, if men are examined separately from women, it can be observed that only men have a statistically significant relationship between D2:D4 ratios and state anxiety and trait anxiety. Moreover, about possible relations between the age of participants and state and trait anxiety, a significant negative relationship was observed, without differences between men and women. However, only subjects with a D2:D4 ratio ≥ 1, without differences between men and women, showed a statistically significant negative linear correlation between their age and their state and trait anxiety. The present data allow us to conclude that a low D2:D4 ratio (<1) represents a protective factor against anxiety in both men and women and that this protection seems likely to act throughout life.
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Affiliation(s)
- Sergio Rinella
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Simona Massimino
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Alessia Sorbello
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | | | - Marinella Coco
- Section of Physiology, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
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15
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Cui J, Xiao R, Ma M, Yuan L, Cohen Kodash R, Zhou X. Children skilled in mental abacus show enhanced non-symbolic number sense. CURRENT PSYCHOLOGY 2022. [DOI: 10.1007/s12144-020-00717-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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16
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Lidborg LH, Cross CP, Boothroyd LG. A meta-analysis of the association between male dimorphism and fitness outcomes in humans. eLife 2022; 11:e65031. [PMID: 35179485 PMCID: PMC9106334 DOI: 10.7554/elife.65031] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/17/2022] [Indexed: 11/13/2022] Open
Abstract
Humans are sexually dimorphic: men and women differ in body build and composition, craniofacial structure, and voice pitch, likely mediated in part by developmental testosterone. Sexual selection hypotheses posit that, ancestrally, more 'masculine' men may have acquired more mates and/or sired more viable offspring. Thus far, however, evidence for either association is unclear. Here, we meta-analyze the relationships between six masculine traits and mating/reproductive outcomes (96 studies, 474 effects, N = 177,044). Voice pitch, height, and testosterone all predicted mating; however, strength/muscularity was the strongest and only consistent predictor of both mating and reproduction. Facial masculinity and digit ratios did not significantly predict either. There was no clear evidence for any effects of masculinity on offspring viability. Our findings support arguments that strength/muscularity may be sexually selected in humans, but cast doubt regarding selection for other forms of masculinity and highlight the need to increase tests of evolutionary hypotheses outside of industrialized populations.
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Affiliation(s)
- Linda H Lidborg
- Department of Psychology, Durham UniversityDurhamUnited Kingdom
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17
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Foley DP, Cox CT, Foley AS, Nisbet RJ, Kharbat AF, MacKay BJ. Predicting metacarpal length using paired ratios with bilateral X-ray films. SAGE Open Med 2021; 9:20503121211064177. [PMID: 34956644 PMCID: PMC8704191 DOI: 10.1177/20503121211064177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 11/14/2021] [Indexed: 12/04/2022] Open
Abstract
Introduction: When the metacarpal bones sustain severe osseous injury requiring reconstruction, functional recovery relies on the precise distribution of tension throughout full range of motion. While the small scale of hand structures compounds the effects of altering normal anatomy, literature lacks consensus recommendations for the acceptable degree of length alteration and/or appropriate methods of length estimation in reconstructive procedures. Length asymmetry has been reported in human metacarpal bones; however, studies assessing this phenomenon in living subjects with attention to functional implications or length prediction are lacking. Methods: Hand X-rays were obtained for 34 patients aged 25–80 without history of metacarpal trauma, joint degeneration, or pathologic bone metabolism. A scaled bivariate model predicted metacarpal length using an ipsilateral paired metacarpal and matching contralateral ratio: Estimate_Dx_R = Median_Dy_R * (Median_Dx_L/Median_Dy_L). A second set of predictions used the contralateral metacarpal as a control. Pearson correlation coefficients, paired t-tests, and chi-square tests evaluated the symmetry between bilateral metacarpal lengths and paired metacarpal ratios as well as the accuracy of each predictive method. Results: The contralateral control and target metacarpal differed significantly in digits 1, 2, 3, and 5. No significant difference in matched metacarpal ratios of the right and left hands was found. For all digits except 5D, bivariate model predictions generated were more strongly correlated with actual target length. Chi-square tests did not detect a significant difference in predictive value of the two models. Conclusion: The scaled bivariate model we describe may be useful and economic in generating accurate length estimates of metacarpals for reconstructive procedures.
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Affiliation(s)
- David P Foley
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Cameron T Cox
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Allison S Foley
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Rebecka J Nisbet
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Abdurrahman F Kharbat
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Brendan J MacKay
- Department of Orthopaedic Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA.,University Medical Center, Lubbock, TX, USA
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18
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Holmes L, Watts-Overall TM, Slettevold E, Gruia DC, Raines J, Rieger G. Sexual Orientation, Sexual Arousal, and Finger Length Ratios in Women. ARCHIVES OF SEXUAL BEHAVIOR 2021; 50:3419-3432. [PMID: 34297214 PMCID: PMC8604855 DOI: 10.1007/s10508-021-02095-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
In general, women show physiological sexual arousal to both sexes. However, compared with heterosexual women, homosexual women are more aroused to their preferred sex, a pattern typically found in men. We hypothesized that homosexual women's male-typical arousal is due to their sex-atypical masculinization during prenatal development. We measured the sexual responses of 199 women (including 67 homosexual women) via their genital arousal and pupil dilation to female and male sexual stimuli. Our main marker of masculinization was the ratio of the index to ring finger, which we expected to be lower (a masculine pattern) in homosexual women due to increased levels of prenatal androgens. We further measured observer- and self-ratings of psychological masculinity-femininity as possible proxies of prenatal androgenization. Homosexual women responded more strongly to female stimuli than male stimuli and therefore had more male-typical sexual responses than heterosexual women. However, they did not have more male-typical digit ratios, even though this difference became stronger if analyses were restricted to white participants. Still, variation in women's digit ratios did not account for the link between their sexual orientation and their male-typical sexual responses. Furthermore, homosexual women reported and displayed more masculinity than heterosexual women, but their masculinity was not associated with their male-typical sexual arousal. Thus, women's sexual and behavioral traits, and potential anatomical traits, are possibly masculinized at different stages of gestation.
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Affiliation(s)
- Luke Holmes
- Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK.
| | - Tuesday M Watts-Overall
- Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK
- School of Psychology, University of East London, London, UK
| | - Erlend Slettevold
- Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK
- Department of Medicine and Health Sciences, University of East Anglia, Norwich, UK
| | - Dragos C Gruia
- Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK
| | - Jamie Raines
- Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK
| | - Gerulf Rieger
- Department of Psychology, University of Essex, Colchester, CO4 3SQ, UK
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19
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Banyeh M, Amidu N, Quaye L. The relationship between 2D:4D ratio and postpartum adult female variables in a Ghanaian population. Am J Hum Biol 2021; 34:e23680. [PMID: 34523769 DOI: 10.1002/ajhb.23680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVES Postpartum hematological and anthropometric assessment is a requirement for optimal maternal and child health. The study aimed to determine the relationship between the 2D:4D ratio and postpartum hematological and anthropometric variables in adult females. METHODS The study was cross-sectional from December 2020 to April 2021 involving 272 postpartum adult females, aged between 18 and 36 years. The right (2D:4DR) and the left (2D:4DL) digit ratios were measured using computer-assisted analysis. Fasting venous samples were collected at a median (interquartile range) of 111 (44-210) days postpartum and analyzed for total testosterone (TT), estradiol, sex hormone-binding globulin, and complete blood count. RESULTS The mean ± standard deviation 2D:4DR and 2D:4DL were 0.94 ± 0.04 and 0.93 ± 0.04, respectively. As expected, the TT (r = -0.198, p = .015) and the free androgen index (FAI: r = -0.186, p = .019) were inversely correlated with the 2D:4DL while free testosterone (FT%: r = -0.157, p = .038) was inversely correlated with the 2D:4DR. The absolute basophile count (BASO: r = -0.124, p = .040) and the Platelet-lymphocyte ratio (PLR: r = -0.153, p = .016) were inversely correlated with the 2D:4DL and the 2D:4DR respectively. In addition, the mean cell volume was inversely correlated with the 2D:4DR (r = -0.139, p = .024) and the 2D:4DL (r = -0.122, p = .045). Moreover, the 2D:4DR was inversely correlated with height (r = -0.164, p = .007). Unexpectedly, the red blood cell count (RBC: r = 0.138, p = .025) was positively correlated with the 2D:4DR. CONCLUSION There are significant relationships between the 2D:4D ratio and postpartum female variables. These findings are useful preliminary reference data for postpartum research and subsequent 2D:4D ratio studies.
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Affiliation(s)
- Moses Banyeh
- Department of Biomedical Laboratory Science, School of Allied Health Sciences, University for Development Studies, Tamale, Ghana
| | - Nafiu Amidu
- Department of Biomedical Laboratory Science, School of Allied Health Sciences, University for Development Studies, Tamale, Ghana
| | - Lawrence Quaye
- Department of Biomedical Laboratory Science, School of Allied Health Sciences, University for Development Studies, Tamale, Ghana
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20
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Kyselicová K, Belica I, Vidošovičová M, Janšáková K, Neščáková E, Špajdel M, Navarová S, Ostatníková D. Autism spectrum disorder and new perspectives on the reliability of second to fourth digit ratio. Dev Psychobiol 2021; 63:e22122. [PMID: 33942898 DOI: 10.1002/dev.22122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 02/01/2021] [Accepted: 03/19/2021] [Indexed: 11/06/2022]
Abstract
The second to fourth digit ratio (2D:4D) is according to previous studies a likely biomarker for prenatal testosterone exposure and its effect on the human brain. It was found to be linked to autism spectrum disorders (ASD). Recently, 2D:4D raised a lot of questions with regard to its stability and autism-related behaviors. Here, we present a cross-sectional study of 2D:4D in boys (N = 91, mean age 7.63) and adults (N = 36 mean age 22.8) with ASD as well as neurotypical students, 506 participants in total. Digit ratio was assessed by taking measurements from digital scans, compared between groups and correlated with the autism quotient. Significant differences were found in the digit ratio of children and adults. Both girls and boys had 2D:4D ratio lower than women and men, both on the right (p = 0.000 in females, p = 0.000 in males) and left hand (p = 0.018 in females, p = 0.011 in males). No significant differences were found in digit ratios between neurotypical subjects and those with ASD nor was there a relationship with the reported autistic traits, which leads us to question the reliability of 2D:4D and its relation to ASD.
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Affiliation(s)
- Klaudia Kyselicová
- Institute of Physiology, Academic Research Center for Autism, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Ivan Belica
- Institute of Physiology, Academic Research Center for Autism, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Mária Vidošovičová
- Institute of Physiology, Academic Research Center for Autism, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Katarína Janšáková
- Institute of Physiology, Academic Research Center for Autism, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Eva Neščáková
- Department of Anthropology, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Marián Špajdel
- Department of Psychology, Faculty of Philosophy and Arts, Trnava University, Trnava, Slovakia
| | - Simona Navarová
- Department of Psychology, Faculty of Philosophy and Arts, Trnava University, Trnava, Slovakia
| | - Daniela Ostatníková
- Institute of Physiology, Academic Research Center for Autism, Faculty of Medicine, Comenius University, Bratislava, Slovakia
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21
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Chinese kindergarteners skilled in mental abacus have advantages in spatial processing and attention. COGNITIVE DEVELOPMENT 2021. [DOI: 10.1016/j.cogdev.2021.101046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Richards G, Beking T, Kreukels BPC, Geuze RH, Beaton AA, Groothuis T. An examination of the influence of prenatal sex hormones on handedness: Literature review and amniotic fluid data. Horm Behav 2021; 129:104929. [PMID: 33454315 DOI: 10.1016/j.yhbeh.2021.104929] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 01/27/2023]
Abstract
Competing theories have posited roles for foetal androgen exposure in the development of human handedness. However, due to practical and ethical considerations, few studies have used hormonal measures to examine this possibility. The current paper reviews this literature and reveals a generally inconsistent pattern of results. We also present data from a longitudinal study of prenatal sex hormone exposure and subsequent handedness. More specifically, we examine correlations between testosterone and estradiol measured from second trimester amniotic fluid and hand preference (Dutch language version of the Edinburgh Handedness Inventory) and hand skill asymmetry (pegboard task) measured at 15 years of age. Prenatal sex hormone exposure was not associated with the direction of hand preference in either males or females. However, in females, high levels of prenatal testosterone were associated with weaker lateralisation of hand skill, and high levels of prenatal estradiol were associated with weaker hand preference. In addition, high levels of prenatal testosterone were associated with increased task duration (i.e., slow hand speed) for the right and left hands of males. The pattern of results observed here is not entirely consistent with any of the main theories linking sex hormones with handedness, suggesting that an association between these variables may be more complex than initially thought.
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Affiliation(s)
- Gareth Richards
- Newcastle University, School of Psychology, Ridley Building 1, Queen Victoria Road, Newcastle upon Tyne NE1 7RU, UK; University of Cambridge, Autism Research Centre, Department of Psychiatry, Douglas House, 18b Trumpington Road, Cambridge CB2 8AH, UK.
| | - Tess Beking
- University of Groningen, Faculty of Behavioural and Social Sciences, Department Clinical & Developmental Neuropsychology, Grote Kruisstraat 2/1, 9712 TS Groningen, the Netherlands; Amsterdam University Medical Center, location VUmc, Department of Medical Psychology, Center of Expertise on Gender Dysphoria, PO Box 7057, 1007 MB Amsterdam, the Netherlands; University of Groningen, Groningen Institute for Evolutionary Life Sciences, Nijenborgh 7, 9747 AG Groningen, the Netherlands
| | - Baudewijntje P C Kreukels
- Amsterdam University Medical Center, location VUmc, Department of Medical Psychology, Center of Expertise on Gender Dysphoria, PO Box 7057, 1007 MB Amsterdam, the Netherlands
| | - Reint H Geuze
- University of Groningen, Faculty of Behavioural and Social Sciences, Department Clinical & Developmental Neuropsychology, Grote Kruisstraat 2/1, 9712 TS Groningen, the Netherlands
| | - Alan A Beaton
- Swansea University, Department of Psychology, School of Human & Health Sciences, Swansea SA2 8PP, UK; Aberystwyth University, Department of Psychology, Aberystwyth SY23 3UX, UK
| | - Ton Groothuis
- University of Groningen, Groningen Institute for Evolutionary Life Sciences, Nijenborgh 7, 9747 AG Groningen, the Netherlands
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23
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Rajawat A, Majeti C, Podugu UK, Kaushik M, Nagamaheshwari X, Mehra N. Association of Hormonal Fingerprints and Dental Caries: A Pilot Study. J Conserv Dent 2021; 23:337-340. [PMID: 33623232 PMCID: PMC7883784 DOI: 10.4103/jcd.jcd_367_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/30/2020] [Accepted: 09/15/2020] [Indexed: 11/22/2022] Open
Abstract
Context: Dental caries remains the most widespread oral disease among all age groups. Hormonal fingerprints (second digit: fourth digit ratio or 2D:4D ratio) are biomarkers displaying sexual dimorphism and diverse human phenotypic traits. A person's genetic makeup may influence the occurrence of dental caries. Aim: The present study aimed to evaluate the influence of digit ratio on the incidence of dental caries. Settings and Design: Two hundred patients between 18 and 55 years, reporting for restorations or endodontic therapy, participated in the study. Subjects and Methods: Hormonal fingerprints (2D:4D ratio) were measured with the help of a digital vernier caliper. Caries incidence was recorded using the DMFT index. Statistical Analysis used: Data obtained were tabulated and statistically analyzed using Independent t-test and Chi-square test. Results Males had a less mean 2D:4D ratio than females, which was statistically significant (p-value = 0.003). Chi-square test was applied, and there was a statistically significant correlation between high digit ratio and caries experience (p-value = 0.002). Females with a high digit ratio and males with a low digit ratio were in the moderate and low caries risk groups with a p-value of 0.029 and 0.001 in the respective risk groups. Conclusion The present study displayed a correlation between hormonal fingerprints (2D:4D ratio) and dental caries. An indicator of caries risk will help prevent caries by implementing oral hygiene measures, which will reduce its incidence as the most occurring oral disease.
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Affiliation(s)
- Akansha Rajawat
- Department of Conservative Dentistry and Endodontics, Army College of Dental Sciences, Secunderabad, Telangana, India
| | - Chandrakanth Majeti
- Department of Conservative Dentistry and Endodontics, Army College of Dental Sciences, Secunderabad, Telangana, India
| | - Uday Kumar Podugu
- Department of Conservative Dentistry and Endodontics, Army College of Dental Sciences, Secunderabad, Telangana, India
| | - Mamta Kaushik
- Department of Conservative Dentistry and Endodontics, Army College of Dental Sciences, Secunderabad, Telangana, India
| | - X Nagamaheshwari
- Department of Conservative Dentistry and Endodontics, Army College of Dental Sciences, Secunderabad, Telangana, India
| | - Neha Mehra
- Department of Conservative Dentistry and Endodontics, Army College of Dental Sciences, Secunderabad, Telangana, India
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24
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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.
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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
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25
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Nepomuceno MV, Stenstrom E. Consumption on steroids: The effect of testosterone on preferences for conspicuous consumption and the moderating role of intrasexual competition. JOURNAL OF BEHAVIORAL DECISION MAKING 2021. [DOI: 10.1002/bdm.2222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Eric Stenstrom
- Marketing Department, Farmer School of Business Miami University Oxford OH USA
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26
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Association patterns between 2D:4D ratio and age at menarche: the impact of methodology. ANTHROPOLOGICAL REVIEW 2020. [DOI: 10.2478/anre-2020-0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The ratio of index finger to ring finger length (2D:4D) is a sexually dimorphic feature and widely used as an indicator of prenatal androgen-estrogen exposure. Several studies have investigated the relationship between the 2D:4D ratio and the onset of the first menstrual period (menarche) in women.
The present study tested the association patterns between 2D:4D ratio and age at menarche. Furthermore, the impact of methods of measuring finger lengths was considered.
Two samples were used to conduct the study. One sample consisted of 110 women who self-measured their finger lengths. The finger length measurements in the second sample (88 women) were taken from one trained observer using the caliper-based technique. Age at menarche was determined using a retrospective method.
Women from the first sample reported an average age for the onset of the first menstrual bleeding at 12.9 (SD = 1.4) years of age. There was no significant association between the left and right 2D:4D ratio and the age at menarche. The second sample showed a mean age at menarche at 12.8 (SD = 1.3) years of age. Here, the right hand 2D:4D ratio and age at menarche were significantly correlated (p<0.001).
A more feminine 2D:4D ratio was significantly associated with an earlier menarcheal age only in the sample with direct finger length measurements by a trained investigator. The sample using self-measurements yielded no significant associations between menarcheal age and 2D:4D. The use of a reliable and well-founded methodology is essential for obtaining meaningful results.
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27
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Yune S, Lee H, Kim M, Tajmir SH, Gee MS, Do S. Beyond Human Perception: Sexual Dimorphism in Hand and Wrist Radiographs Is Discernible by a Deep Learning Model. J Digit Imaging 2020; 32:665-671. [PMID: 30478479 PMCID: PMC6646498 DOI: 10.1007/s10278-018-0148-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Despite the well-established impact of sex and sex hormones on bone structure and density, there has been limited description of sexual dimorphism in the hand and wrist in the literature. We developed a deep convolutional neural network (CNN) model to predict sex based on hand radiographs of children and adults aged between 5 and 70 years. Of the 1531 radiographs tested, the algorithm predicted sex correctly in 95.9% (κ = 0.92) of the cases. Two human radiologists achieved 58% (κ = 0.15) and 46% (κ = − 0.07) accuracy. The class activation maps (CAM) showed that the model mostly focused on the 2nd and 3rd metacarpal base or thumb sesamoid in women, and distal radioulnar joint, distal radial physis and epiphysis, or 3rd metacarpophalangeal joint in men. The radiologists reviewed 70 cases (35 females and 35 males) labeled with sex along with heat maps generated by CAM, but they could not find any patterns that distinguish the two sexes. A small sample of patients (n = 44) with sexual developmental disorders or transgender identity was selected for a preliminary exploration of application of the model. The model prediction agreed with phenotypic sex in only 77.8% (κ = 0.54) of these cases. To the best of our knowledge, this is the first study that demonstrated a machine learning model to perform a task in which human experts could not fulfill.
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Affiliation(s)
- Sehyo Yune
- Department of Radiology, Massachusetts General Hospital, 25 New Chardon Street Suite 400B, Boston, MA, 02114, USA
| | - Hyunkwang Lee
- Department of Radiology, Massachusetts General Hospital, 25 New Chardon Street Suite 400B, Boston, MA, 02114, USA
| | - Myeongchan Kim
- Department of Radiology, Massachusetts General Hospital, 25 New Chardon Street Suite 400B, Boston, MA, 02114, USA
| | - Shahein H Tajmir
- Department of Radiology, Massachusetts General Hospital, 25 New Chardon Street Suite 400B, Boston, MA, 02114, USA
| | - Michael S Gee
- Department of Radiology, Massachusetts General Hospital, 25 New Chardon Street Suite 400B, Boston, MA, 02114, USA
| | - Synho Do
- Department of Radiology, Massachusetts General Hospital, 25 New Chardon Street Suite 400B, Boston, MA, 02114, USA.
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Zhou X, Hu Y, Yuan L, Gu T, Li D. Visual form perception predicts 3-year longitudinal development of mathematical achievement. Cogn Process 2020; 21:521-532. [PMID: 32556792 DOI: 10.1007/s10339-020-00980-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 06/03/2020] [Indexed: 11/30/2022]
Abstract
Numerous studies have demonstrated an association between approximate number system (ANS) acuity and mathematical performance. Studies have also shown that ANS acuity can predict the longitudinal development of mathematical achievement. Visual form perception in the current investigation was proposed to account for the predictive role of ANS acuity in the development of mathematical achievement. One hundred and eighty-eight school children (100 males, 88 females; mean age = 12.2 ± 0.3 years) participated in the study by completing five tests: numerosity comparison, figure matching, mental rotation, nonverbal matrix reasoning, and choice reaction time. Three years later, they took a mathematical achievement test. We assessed whether the early tests predicted mathematical achievement at the later date. Analysis showed that the ANS acuity measured via numerosity comparison significantly predicted mathematical achievement 3 years later, even when controlling for individual differences in mental rotation, nonverbal matrix reasoning, and choice reaction time, as well as age and gender differences. Hierarchical regression and mediation analyses further showed that the longitudinal predictive role of ANS acuity in mathematical achievement was interpreted by visual form perception measured with a figure-matching test. Together, these results indicate that visual form perception may be the underlying cognitive mechanism that links ANS acuity to mathematical achievement in terms of longitudinal development.
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Affiliation(s)
- Xinlin Zhou
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Faculty of Psychology, Beijing Normal University, Beijing, 100875, China. .,Advanced Innovation Center for Future Education and Siegler Center for Innovative Learning, Beijing Normal University, Beijing, 100875, China.
| | - Yuwei Hu
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Faculty of Psychology, Beijing Normal University, Beijing, 100875, China.,Advanced Innovation Center for Future Education and Siegler Center for Innovative Learning, Beijing Normal University, Beijing, 100875, China
| | - Li Yuan
- State Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Faculty of Psychology, Beijing Normal University, Beijing, 100875, China.,Advanced Innovation Center for Future Education and Siegler Center for Innovative Learning, Beijing Normal University, Beijing, 100875, China
| | - Tianan Gu
- Institute of Public Administration and Human Resources, Development Research Center of the State Council, Beijing, 100010, China
| | - Dawei Li
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA
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Swift-Gallant A, Johnson BA, Di Rita V, Breedlove SM. Through a glass, darkly: Human digit ratios reflect prenatal androgens, imperfectly. Horm Behav 2020; 120:104686. [PMID: 32014464 DOI: 10.1016/j.yhbeh.2020.104686] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 01/09/2020] [Indexed: 01/07/2023]
Abstract
On average, the length of the index finger (digit 2) divided by the length of the ring finger (digit 4) on the right hand, is greater in women than in men. Converging evidence makes it clear that prenatal androgens affect the development of digit ratios in humans and so are likely responsible for this sex difference. Thus, differences in 2D:4D between groups within a sex may be due to average differences between those groups in prenatal androgen exposure. There have been many reports that lesbians, on average, have a smaller (more masculine) digit ratio than straight women, which has been confirmed by metaanalysis. These findings indicate that lesbians were, on average, exposed to greater prenatal androgen than straight women, which further indicates that greater levels of prenatal androgen predispose humans to be attracted to women in adulthood. Nevertheless, these results only apply to group differences between straight women and lesbians; digit ratios cannot be used to classify individual women as gay or straight.
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Affiliation(s)
- Ashlyn Swift-Gallant
- Department of Psychology, Memorial University of Newfoundland, St. Johns, NL A1B 3X9, Canada
| | - Brandon A Johnson
- Neuroscience Program, Michigan State University, United States of America
| | - Victor Di Rita
- Neuroscience Program, Michigan State University, United States of America
| | - S Marc Breedlove
- Neuroscience Program, Michigan State University, United States of America; Department of Psychology, Michigan State University, United States of America.
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30
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Butovskaya M, Marczak M, Misiak M, Karelin D, Białek M, Sorokowski P. Approach to Resource Management and Physical Strength Predict Differences in Helping: Evidence From Two Small-Scale Societies. Front Psychol 2020; 11:373. [PMID: 32269535 PMCID: PMC7110700 DOI: 10.3389/fpsyg.2020.00373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/18/2020] [Indexed: 01/16/2023] Open
Abstract
Helping behavior is likely to have evolved to increase chances of survival of an individual and their group. Nevertheless, populations differ significantly in their eagerness to help, and little is known about populational and inter-individual determinants of these differences. Previous studies indicated that economic and physiological factors might influence helping behavior. The aim of the present study was to investigate the effects of approach to resource management of a society (immediate-return economy vs. delayed-return economy), prenatal androgenization (based on second-to-fourth digit ratio), and physical strength (based on hand grip strength) on helping behavior toward others. Helping was assessed in terms of both general eagerness to help and differential helping toward: (1) kin, (2) other group members indiscriminately, (3) friends, and (4) those from whom help was obtained in the past. Based on data collected in two small-scale societies (n = 306), we found that people in the egalitarian immediate-return society (the Hadza hunter-gatherers of Tanzania) displayed helping behavior significantly more often than people in a more stratified delayed-return economy (Yali horticulturalists of Papua). Additionally, our results revealed that physical strength was a significant predictor of helping behavior in women but not in men. We discuss our findings in the light of the adaptive value of helping behavior.
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Affiliation(s)
- Marina Butovskaya
- Institute of Ethnology and Anthropology, RAS, Moscow, Russia.,National Research University Higher School of Economics, Moscow, Russia
| | - Michalina Marczak
- Institute of Psychology, University of Wrocław, Wrocław, Poland.,Institute of Psychology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Michał Misiak
- Institute of Psychology, University of Wrocław, Wrocław, Poland
| | | | - Michał Białek
- Institute of Psychology, University of Wrocław, Wrocław, Poland
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Stibbard-Hawkes DNE. No Association between 2D:4D Ratio and Hunting Success among Hadza Hunters. HUMAN NATURE (HAWTHORNE, N.Y.) 2020; 31:22-42. [PMID: 31838723 DOI: 10.1007/s12110-019-09359-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ratio of index- and ring-finger lengths (2D:4D ratio) is thought to be related to prenatal androgen exposure, and in many, though not all, populations, men have a lower average digit ratio than do women. In many studies an inverse relationship has been observed, among both men and women, between 2D:4D ratio and measures of athletic ability. It has been further suggested that, in hunter-gatherer populations, 2D:4D ratio might also be negatively correlated with hunting ability, itself assumed to be contingent on athleticism. This hypothesis has been tested using endurance running performance among runners from a Western, educated, and industrialized population as a proximate measure of hunting ability. However, it has not previously been tested among actual hunter-gatherers using more ecologically valid measures of hunting ability and success. The current study addresses this question among Tanzanian Hadza hunter-gatherers. I employ a novel method of assessing hunting reputation that, unlike previous methods, allows granular distinctions to be made between hunters at all levels of perceived ability. I find no statistically significant relationship between digit ratio and either hunting reputation or two important hunting skills. I confirm that Hadza men have higher mean 2D:4D ratios than men in many Western populations. I discuss the notion that 2D:4D ratio may be the consequence of an allometric scaling relationship between relative and absolute finger lengths. Although it is difficult to draw clear conclusions from these results, the current study provides no support for the theorized relationship between 2D:4D ratio and hunting skill.
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Kalichman L, Batsevich V, Kobyliansky E. Finger length ratio in longevity populations. Am J Hum Biol 2019; 32:e23325. [PMID: 31566838 DOI: 10.1002/ajhb.23325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 08/28/2019] [Accepted: 08/29/2019] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES The purpose of this study was to compare the prevalence of finger length ratio between three longevity populations (Abkhazians, Azerbaijanis, and Georgians) and one nonlongevity population (Russians), as well as between a longevity and nonlongevity sample within one ethnic group (Abkhazians). METHODS In a cross-sectional observational study, we compared the prevalence of finger length ratio in longevity vs nonlongevity samples. RESULTS A negative relationship was observed between longevity index and prevalence of type 1 (feminine type) ratio. In longevity samples, the prevalence of type 1 ratio was lower and the prevalence of type 3 (masculine type) ratio was higher than in the nonlongevity sample of Russians. This difference was statistically significant (P < .001) in both males and females. A similar difference between longevity and nonlongevity samples was exhibited in the Abkhazian samples. In males and females, a significantly higher prevalence of type 1 and lower type 3 finger ratios (P < .001) were shown in the nonlongevity samples. CONCLUSIONS Finger length ratio pattern in longevity populations differs from that of nonlongevity populations. In longevity samples, the prevalence of type 1 ratio was lower and the prevalence of type 3 ratio was higher vs the nonlongevity sample. A similar type of difference was seen in the longevity and nonlongevity samples belonging to one ethnic group, the Abkhazians. Previous studies found that the type 1 finger length ratio was related to important morbidities that have a potential for shortening the life span. This can be one of the most plausible explanations for our findings.
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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
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Nadler A, Camerer CF, Zava DT, Ortiz TL, Watson NV, Carré JM, Nave G. Does testosterone impair men's cognitive empathy? Evidence from two large-scale randomized controlled trials. Proc Biol Sci 2019; 286:20191062. [PMID: 31480979 DOI: 10.1098/rspb.2019.1062] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The capacity to infer others' mental states (known as 'mind reading' and 'cognitive empathy') is essential for social interactions across species, and its impairment characterizes psychopathological conditions such as autism spectrum disorder and schizophrenia. Previous studies reported that testosterone administration impaired cognitive empathy in healthy humans, and that a putative biomarker of prenatal testosterone exposure (finger digit ratios) moderated the effect. However, empirical support for the relationship has relied on small sample studies with mixed evidence. We investigate the reliability and generalizability of the relationship in two large-scale double-blind placebo-controlled experiments in young men (n = 243 and n = 400), using two different testosterone administration protocols. We find no evidence that cognitive empathy is impaired by testosterone administration or associated with digit ratios. With an unprecedented combined sample size, these results counter current theories and previous high-profile reports, and demonstrate that previous investigations of this topic have been statistically underpowered.
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Affiliation(s)
| | - Colin F Camerer
- Department of the Humanities and Social Sciences, California Institute of Technology, 1200 E California Boulevard, MC 228-77, Pasadena, CA 91125, USA
| | - David T Zava
- ZRT Laboratory, 8605 SW Creekside Place, Beaverton, OR 97008, USA
| | - Triana L Ortiz
- Department of Psychology, Nipissing University, 100 College Drive, North Bay, Ontario, Canada P1B 8L7
| | - Neil V Watson
- Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6
| | - Justin M Carré
- Department of Psychology, Nipissing University, 100 College Drive, North Bay, Ontario, Canada P1B 8L7
| | - Gideon Nave
- Marketing Department, The Wharton School of the University of Pennsylvania, 3730 Walnut Street, Philadelphia, PA 19104, USA
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Králík M, Hupková A, Zeman T, Hložek M, Hlaváček L, Slováčková M, Čuta M, Urbanová P. Family effects on the digit ratio (2D:4D): The role of the interbirth interval. Am J Hum Biol 2019; 31:e23260. [PMID: 31183942 DOI: 10.1002/ajhb.23260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/26/2019] [Accepted: 05/12/2019] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVES Family represents the closest social environment that immediately affects human ontogeny from an early prenatal period. This study aimed to assess sibship influences on the second-to-fourth digit length ratio (2D:4D ratio). METHODS The source sample represented 329 children aged 6.5 to 15.8 years (Czech Republic), including a subsample of 75 sibling pairs. A combination of (a) between-family design (cross-sectional sample) and (b) within-family design (pairs of siblings) was used to study the effect of family variables and interbirth interval (IBI) on the 2D:4D ratio. RESULTS Birth order, number of siblings (except for younger sisters), and sex ratio in siblings were significantly related to the 2D:4D ratio on the right, left, or both hands. At the same time, the relationships were opposite in males and females for birth order, number of older brothers and number of children in the family--increasing values in these variables increased digit ratio in males but decreased digit ratio in females. Mean difference in 2D:4D ratio (DIFF) within pairs (older minus younger sibling) differed from zero only in the "older sister--younger brother" group, where DIFF did not depend on IBI. On the contrary, in remaining pair types the DIFF tended to change with IBI, the strongest in the "older brother--younger sister" pairs. CONCLUSIONS Family variables, especially number of older brothers, should be considered as important confounding factors in 2D:4D ratio studies. However, the effect of these variables might be modified by IBI.
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Affiliation(s)
- Miroslav Králík
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Adela Hupková
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Tomáš Zeman
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Martin Hložek
- Department of Archaeology and Museology, Faculty of Arts, Masaryk University, Brno, Czech Republic
| | - Lukáš Hlaváček
- Palacký University Olomouc, Conference Services, Olomouc, Czech Republic
| | - Marie Slováčková
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Martin Čuta
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Petra Urbanová
- Laboratory of Morphology and Forensic Anthropology (LaMorFA), Department of Anthropology, Faculty of Science, Masaryk University, Brno, Czech Republic
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35
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Visual form perception is fundamental for both reading comprehension and arithmetic computation. Cognition 2019; 189:141-154. [PMID: 30953825 DOI: 10.1016/j.cognition.2019.03.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 03/19/2019] [Accepted: 03/21/2019] [Indexed: 01/05/2023]
Abstract
Visual perception has been found to be a critical factor for reading comprehension and arithmetic computation in separate lines of research with different measures of visual form perception. The current study of 1099 Chinese elementary school students investigated whether the same visual form perception (assessed by a geometric figure matching task) underlies both reading comprehension and arithmetic computation. The results showed that visual form perception had close relations with both reading comprehension and arithmetic computation, even after controlling for age, gender, and cognitive factors such as processing speed, attention, working memory, visuo-spatial processing, and general intelligence. Results also showed that numerosity comparison's relations with reading comprehension and arithmetic computation were fully accounted for by visual form perception. These results suggest that reading comprehension and arithmetic computation might share a similar visual form processing mechanism.
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36
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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.
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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
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Borráz-León JI, Rantala MJ, Cerda-Molina AL. Digit ratio (2D:4D) and facial fluctuating asymmetry as predictors of the dark triad of personality. PERSONALITY AND INDIVIDUAL DIFFERENCES 2019. [DOI: 10.1016/j.paid.2018.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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38
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Sex differences in relationship between body composition and digit length ratio (2D:4D) in students of military courses. ANTHROPOLOGICAL REVIEW 2018. [DOI: 10.2478/anre-2018-0034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It is believed that the second to fourth finger length ratio is an indirect indicator of fetal testosterone levels. It is pointed out that there is a relationship between the 2nd to 4th finger length ratio and the body structure in women and men. Studies on the relationship between body composition and 2D:4D finger length among military students have not been carried out so far. The work aims to determine the dependence of body composition and the quotient of the 2nd and 4th fingers length of military students. The research material has been gathered as a result of examinations of women and men studying military subjects. The study involved 55 women and 65 men. The tests included anthropometric measurements (body height, body weight, length of the second and the fourth fingers) and body composition measurements. As a result of the tests, no dimorphic differentiations in the digit length ratio (2D:4D) was indicated. The BMI, muscle mass, lean body mass and water in the body demonstrated higher values in men than in women. However, the fat content in men was low. It was found that the relationship exists between muscle mass, lean mass and total water content in the body and the 2D:4D finger length ratio in the left hand in women. A higher level of fetal testosterone, characterized by lower values of the 2nd to 4th finger length ratio, may be associated with a higher content of muscle mass, lean body mass and water in the body of adult women leading a similar lifestyle.
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Watts TM, Holmes L, Raines J, Orbell S, Rieger G. Finger Length Ratios of Identical Twins with Discordant Sexual Orientations. ARCHIVES OF SEXUAL BEHAVIOR 2018; 47:2435-2444. [PMID: 29978344 DOI: 10.1007/s10508-018-1262-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 04/17/2018] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
A proposed marker of prenatal androgen exposure is the ratio of the index finger to ring finger (2D:4D). Within each sex, this ratio may be lower for those who were exposed to higher levels of androgens and become attracted to women, as compared to those who were exposed to lower levels of androgens and become attracted to men. We examined these patterns in identical twins with discordant sexual orientations. Because these twins are genetically identical, differences in prenatal androgen exposure, as reflected in their different finger length ratios, might contribute to their discordance. For 18 female twin pairs, non-straight (bisexual or lesbian) twins had significantly lower, or more masculinized, 2D:4D ratios than their straight co-twins, but only in the left hand. For 14 male pairs, non-straight twins had, contrary to our prediction, more masculinized finger length ratios than straight co-twins, but this difference was not significant. A reanalysis of present and previous data (Hall & Love, 2003; Hiraishi, Sasaki, Shikishima, & Ando, 2012) suggested that these patterns were robust. Furthermore, males had more masculinized 2D:4D ratios than females. This sex difference did not vary by sexual orientation.
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Affiliation(s)
- Tuesday M Watts
- Department of Psychology, University of Essex, Colchester, C04 3SQ, UK.
| | - Luke Holmes
- Department of Psychology, University of Essex, Colchester, C04 3SQ, UK
| | - Jamie Raines
- Department of Psychology, University of Essex, Colchester, C04 3SQ, UK
| | - Sheina Orbell
- Department of Psychology, University of Essex, Colchester, C04 3SQ, UK
| | - Gerulf Rieger
- Department of Psychology, University of Essex, Colchester, C04 3SQ, UK
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40
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Hoskin AW, Meldrum RC. The association between fetal testosterone and violent behavior: Additional evidence using the 2D:4D digit ratio. PERSONALITY AND INDIVIDUAL DIFFERENCES 2018. [DOI: 10.1016/j.paid.2018.06.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bakholdina VY, Movsesian AA, Negasheva MA. Association between the digit ratio (2D:4D) and body fat distribution in Mordovian students. Ann Hum Biol 2018; 45:414-418. [PMID: 30328710 DOI: 10.1080/03014460.2018.1495264] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND The length ratio of the second to the fourth finger (2D:4D) is a possible biomarker of prenatal sex hormone levels, which play a significant role in determining sex-related body traits. AIMS To evaluate the value of the 2D:4D ratio in a Mordovian sample and to test the associations between the 2D:4D ratio and sexually dimorphic morphological traits, such as height and body weight, body mass index, waist and hip circumference, the waist-to-hip ratio, handgrip strength and the skinfold thickness. SUBJECTS AND METHODS The sample studied included 106 individuals of Mordovian ethnicity: 58 males and 48 females, 16-23 years old. The associations between the 2D:4D ratio and morphological traits were evaluated by multivariate regression analysis and correlation analysis. RESULTS The 2D:4D ratio in males was significantly lower than in females. Most of the associations of the 2D:4D ratio with morphological traits were statistically insignificant. The 2D:4D ratio is only significantly correlated with skinfold thickness of the forearm and the abdomen in females. CONCLUSION The association between the 2D:4D ratio and skinfold thickness is indicative of the role of prenatal sex hormones in shaping the body fat distribution in females, along with the significant impact of sex hormones at puberty.
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Affiliation(s)
| | - Alla A Movsesian
- a Department of Anthropology , Lomonosov State University , Moscow , Russian
| | - Marina A Negasheva
- a Department of Anthropology , Lomonosov State University , Moscow , Russian
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Candelo N, Eckel C. The 2D:4D ratio does not always correlate with economic behavior: A field experiment with African-Americans. ECONOMICS AND HUMAN BIOLOGY 2018; 30:172-181. [PMID: 30064037 DOI: 10.1016/j.ehb.2018.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 07/07/2018] [Accepted: 07/11/2018] [Indexed: 06/08/2023]
Abstract
Several studies present evidence of correlations between prenatal testosterone exposure measured with the 2D:4D ratio and behaviors such as pro-social behavior, risk and patient attitudes, and self-employment. Individuals exposed prenatally to higher levels of testosterone have lower levels of risk aversion, higher levels of patience and invest more in others, and in themselves, therefore have higher individual financial wellbeing. We test these hypotheses with a sample of 115 African-Americans who live in a low-income urban area in the U.S. The 2D:4D ratio in our sample of males and females does not have a consistent and robust correlation with risk, patient attitudes, pro-social behavior and self-employment in contrast to previous studies.
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Affiliation(s)
- Natalia Candelo
- CUNY Queens College, 225 E 72nd St #901, New York, NY 10021, USA.
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Pruszkowska-Przybylska P, Sitek A, Rosset I, Sobalska-Kwapis M, Słomka M, Strapagiel D, Żądzińska E. Association of the 2D:4D digit ratio with body composition among the Polish children aged 6-13 years. Early Hum Dev 2018; 124:26-32. [PMID: 30119034 DOI: 10.1016/j.earlhumdev.2018.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/02/2018] [Accepted: 08/07/2018] [Indexed: 12/17/2022]
Abstract
The 2D:4D digit ratio is formed as a result of genetic factors but also prenatal exposure to sex hormones. The higher index value the higher concentration of the prenatal oestrogen. It is commonly known that testosterone is a hormone connected with muscle mass growth and that oestrogen affects adipogenesis. The aim of this study was to find if the digit ratio can be an informative indicator of the fat mass and muscle mass and body proportions in prepubertal children. Material and methods The analysed cohort included 420 children (221 girls and 199 boys) aged 6-13 years. Pearson's and Spearman's tests were conducted to assess whether 2D:4D was significantly correlated with the body composition measurements. Multiple regression models and stepwise forward regression were applied to select the most important independent variables affecting fat mass (%) and muscle mass (%) as well as the BMI and the WHR. Results The study shows that the digit ratio is negatively correlated with muscle mass (MM%) among girls (p < 0.05).There was no similar relationship in the group of boys. The regression models showed a significant role in determining the body composition and body proportions played by maternal factors such as: maternal level of education and weight gain during pregnancy. Conclusions The 2D:4D digit ratio seems to be an informative indicator of the muscle mass development since girls' early childhood. Moreover, maternal environment is also important in forming the offspring's body composition and proportions.
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Affiliation(s)
| | - Aneta Sitek
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Łódź, 90-237, Poland
| | - Iwona Rosset
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Łódź, 90-237, Poland
| | - Marta Sobalska-Kwapis
- The Biobank Lab, Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland; BBMRI.pl Consortium, Wrocław, Poland
| | - Marcin Słomka
- The Biobank Lab, Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland; BBMRI.pl Consortium, Wrocław, Poland
| | - Dominik Strapagiel
- The Biobank Lab, Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland; BBMRI.pl Consortium, Wrocław, Poland
| | - Elżbieta Żądzińska
- Department of Anthropology, Faculty of Biology and Environmental Protection, University of Łódź, 90-237, Poland; Biological Anthropology and Comparative Anatomy Research Unit, School of Medicine, The University of Adelaide, South Australia 5005, Australia
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Akdeniz G, Deniz O, Vural G, Gümüşyayla Ş, Bektaş H. Is digit ratio (2D:4D) an indicator for patients with epilepsy? JOURNAL OF CLINICAL AND EXPERIMENTAL INVESTIGATIONS 2018. [DOI: 10.5799/jcei.433812] [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] Open
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Rodic M, Cui J, Malykh S, Zhou X, Gynku EI, Bogdanova EL, Zueva DY, Y. Bogdanova O, Kovas Y. Cognition, emotion, and arithmetic in primary school: A cross-cultural investigation. BRITISH JOURNAL OF DEVELOPMENTAL PSYCHOLOGY 2018; 36:255-276. [PMID: 29878517 PMCID: PMC6001455 DOI: 10.1111/bjdp.12248] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 04/14/2018] [Indexed: 11/26/2022]
Abstract
The study investigated cross-cultural differences in variability and average performance in arithmetic, mathematical reasoning, symbolic and non-symbolic magnitude processing, intelligence, spatial ability, and mathematical anxiety in 890 6- to 9-year-old children from the United Kingdom, Russia, and China. Cross-cultural differences explained 28% of the variance in arithmetic and 17.3% of the variance in mathematical reasoning, with Chinese children outperforming the other two groups. No cross-cultural differences were observed for spatial ability and mathematical anxiety. In all samples, symbolic magnitude processing and mathematical reasoning were independently related to early arithmetic. Other factors, such as non-symbolic magnitude processing, mental rotation, intelligence, and mathematical anxiety, produced differential patterns across the populations. The results are discussed in relation to potential influences of parental practice, school readiness, and linguistic factors on individual differences in early mathematics. Statement of contribution What is already known on this subject? Cross-cultural differences in mathematical ability are present in preschool children. Similar mechanisms of mathematical development operate in preschool children from the United Kingdom, Russia, and China. Tasks that require understanding of numbers are best predictors of arithmetic in preschool children. What does this study add? Cross-cultural differences in mathematical ability become greater with age/years of formal education. Similar mechanisms of mathematical development operate in early primary school children from the United Kingdom, Russia, and China. Symbolic number magnitude and mathematical reasoning are the main predictors of arithmetic in all three populations.
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Affiliation(s)
- Maja Rodic
- Laboratory for Cognitive Investigations and Behavioural GeneticsTomsk State UniversityTomskRussia
- InLabDepartment of PsychologyGoldsmiths, University of LondonUK
| | - Jiaxin Cui
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Sergey Malykh
- Laboratory for Cognitive Investigations and Behavioural GeneticsTomsk State UniversityTomskRussia
- Psychological InstituteRussian Academy of EducationMoscowRussia
| | - Xinlin Zhou
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Elena I. Gynku
- Laboratory for Cognitive Investigations and Behavioural GeneticsTomsk State UniversityTomskRussia
| | - Elena L. Bogdanova
- Unit of General and Educational PsychologyPsychology DepartmentTomsk State UniversityTomskRussia
| | - Dina Y. Zueva
- Laboratory for Cognitive Investigations and Behavioural GeneticsTomsk State UniversityTomskRussia
| | - Olga Y. Bogdanova
- Unit of General and Educational PsychologyPsychology DepartmentTomsk State UniversityTomskRussia
| | - Yulia Kovas
- Laboratory for Cognitive Investigations and Behavioural GeneticsTomsk State UniversityTomskRussia
- InLabDepartment of PsychologyGoldsmiths, University of LondonUK
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Fisher AD, Ristori J, Morelli G, Maggi M. The molecular mechanisms of sexual orientation and gender identity. Mol Cell Endocrinol 2018; 467:3-13. [PMID: 28847741 DOI: 10.1016/j.mce.2017.08.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/02/2017] [Accepted: 08/15/2017] [Indexed: 12/21/2022]
Abstract
Differences between males and females are widely represented in nature. There are gender differences in phenotypes, personality traits, behaviors and interests, cognitive performance, and proneness to specific diseases. The most marked difference in humans is represented by sexual orientation and core gender identity, the origins of which are still controversial and far from being understood. Debates continue on whether sexual behavior and gender identity are a result of biological (nature) or cultural (nurture) factors, with biology possibly playing a major role. The main goal of this review is to summarize the studies available to date on the biological factors involved in the development of both sexual orientation and gender identity. A systematic search of published evidence was performed using Medline (from January 1948 to June 2017). Review of the relevant literature was based on authors' expertise. Indeed, different studies have documented the possible role and interaction of neuroanatomic, hormonal and genetic factors. The sexual dimorphic brain is considered the anatomical substrate of psychosexual development, on which genes and gonadal hormones may have a shaping effect. In particular, growing evidence shows that prenatal and pubertal sex hormones permanently affect human behavior. In addition, heritability studies have demonstrated a role of genetic components. However, a convincing candidate gene has not been identified. Future studies (e.i. genome wide studies) are needed to better clarify the complex interaction between genes, anatomy and hormonal influences on psychosexual development.
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Affiliation(s)
- Alessandra D Fisher
- Department of Experimental, Clinical and Biomedical Sciences, Careggi University Hospital, Florence, Italy
| | - Jiska Ristori
- Department of Experimental, Clinical and Biomedical Sciences, Careggi University Hospital, Florence, Italy
| | - Girolamo Morelli
- Department of Surgical, Medical, Molecular and of the Critical Area Pathology, University of Pisa, Pisa, Italy
| | - Mario Maggi
- Department of Experimental, Clinical and Biomedical Sciences, Careggi University Hospital, Florence, Italy.
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Alonso J, Di Paolo R, Ponti G, Sartarelli M. Facts and Misconceptions about 2D:4D, Social and Risk Preferences. Front Behav Neurosci 2018; 12:22. [PMID: 29487510 PMCID: PMC5816919 DOI: 10.3389/fnbeh.2018.00022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/25/2018] [Indexed: 11/30/2022] Open
Abstract
We study how the ratio between the length of the second and fourth digit (2D:4D) correlates with choices in social and risk preferences elicitation tasks by building a large dataset from five experimental projects with more than 800 subjects. Our results confirm the recent literature that downplays the link between 2D:4D and many domains of economic interest, such as social and risk preferences. As for the former, we find that social preferences are significantly lower when 2D:4D is above the median value only for subjects with low cognitive ability. As for the latter, we find that a high 2D:4D is not correlated with the frequency of subjects' risky choices.
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Affiliation(s)
- Judit Alonso
- Departamento de Fundamentos de Análisis Económico, Universidad de Alicante, San Vicente del Raspeig/Sant Vicent del Raspeig, Alicante, Spain
| | - Roberto Di Paolo
- Departamento de Fundamentos de Análisis Económico, Universidad de Alicante, San Vicente del Raspeig/Sant Vicent del Raspeig, Alicante, Spain
| | - Giovanni Ponti
- Departamento de Fundamentos de Análisis Económico, Universidad de Alicante, San Vicente del Raspeig/Sant Vicent del Raspeig, Alicante, Spain.,Department of Economics, The University of Chicago, Chicago, IL, United States.,Dipartimento di Economia e Finanza, Libera Università Internazionale degli Studi Sociali Guido Carli (LUISS), Rome, Italy
| | - Marcello Sartarelli
- Departamento de Fundamentos de Análisis Económico, Universidad de Alicante, San Vicente del Raspeig/Sant Vicent del Raspeig, Alicante, Spain
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Verma P, Hegde AM. Digit Ratio and Dental Caries: A Sexually Dimorphic Trait. Int J Clin Pediatr Dent 2018; 11:1-6. [PMID: 29805226 PMCID: PMC5968154 DOI: 10.5005/jp-journals-10005-1474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 12/18/2017] [Indexed: 12/05/2022] Open
Abstract
Dental caries is the most common oral health disease affecting all age groups, races, and geographic locations. The need for the study was to determine the anatomical marker that could predict the taste perception and caries at an early stage. Aim of the study was to determine the correlation between digit ratio and caries experience in school-going children of south Canara region. An observational and cross-sectional pattern was adopted for the present study. The study was then evaluated to find out the correlation between the digit ratio that is thought to be predetermined with caries experience in children of age group 6 to 16 years. In the total sample of 2,037 children, the total population was divided into two categories, i.e., high digit ratio and low digit ratio. Of the total population, 1,112 had low digit ratio and 925 had high digit ratio. Caries experience was highest in low-risk group, followed by moderate, high risk, low risk, and very high risk groups. In all the categories, low digit ratio was affected more than high digit ratio. The study clearly states a positive correlation between digit ratio, taste, social behavior, and dental caries. How to cite this article: Verma P, Hegde AM. Digit Ratio and Dental Caries: A Sexually Dimorphic Trait. Int J Clin Pediatr Dent 2018;11(1):1-6.
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Affiliation(s)
- Priya Verma
- Professor, Department of Pedodontics and Preventive Dentistry, K.D. Dental College & Hospital, Mathura, Uttar Pradesh, India
| | - Amitha M Hegde
- Professor and Head, Department of Pedodontics and Preventive Dentistry, A.B. Shetty Memorial Institute of Dental Sciences, Mangaluru Karnataka, India
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Vásquez-Amézquita M, Leongómez JD, Seto MC, Bonilla FM, Rodríguez-Padilla A, Salvador A. No relation between digit ratio (2D:4D) and visual attention patterns to sexually preferred and non-preferred stimuli. PERSONALITY AND INDIVIDUAL DIFFERENCES 2018. [DOI: 10.1016/j.paid.2017.08.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Schmitz J, Metz GA, Güntürkün O, Ocklenburg S. Beyond the genome—Towards an epigenetic understanding of handedness ontogenesis. Prog Neurobiol 2017; 159:69-89. [DOI: 10.1016/j.pneurobio.2017.10.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 09/18/2017] [Accepted: 10/26/2017] [Indexed: 12/13/2022]
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