Sex Differences in Directional Asymmetry of Digit Length and its Effects on Sex Differences in Digit Ratio (2D:4D)

2008 ◽  
Vol 107 (2) ◽  
pp. 576-586 ◽  
Author(s):  
Martin Voracek ◽  
Denise Offenmüller ◽  
Stefan G. Dressler
Keyword(s):  
Sex Differences ◽  
Ring Finger ◽  
Digit Ratio ◽  
Directional Asymmetry ◽  
Leftward Bias ◽  
First Finding ◽  
The Right ◽  
Putative Marker ◽  
Prenatal Androgen ◽  
Digit Length

Patterns of directional asymmetry in the length of index and ring finger (2D and 4D) may be sexually differentiated. Martin, Puts, and Breedlove (2008) found leftward bias, i.e., both a longer 2D and 4D in the left than in the right hand, more frequently in men, whereas rightward bias occurred more frequently in women. Further, rightward vs leftward bias seemed a substantial source of variation in digit ratio (2D:4D), a putative marker for prenatal androgen levels. Given the generally small effects, unreplicable results, and inconsistent findings of 2D:4D research, these findings potentially are important as the type of directional digit asymmetry could moderate or obfuscate real associations between 2D:4D and target traits. Based on six samples totaling about 3,000 individuals, the present study replicated the first finding of Martin, Puts, and Breedlove (2008): leftward bias was more frequent among men and rightward bias more frequent among women. This sex effect was small. However, the present study did not replicate the second finding of Martin, et al. (2008): relative to participants' sex the contributions of leftward vs rightward asymmetry to individual variation in 2D:4D were smaller by orders of magnitude and not significant. Implications of these findings for 2D:4D research arc discussed.

Finger, Sex, and Side Differences in Fingertip Size and Lack of Association with Image-Based Digit Ratio (2D:4D) Measurements

2008 ◽  
Vol 107 (2) ◽  
pp. 507-512 ◽  
Author(s):  
Martin Voracek ◽  
Jakob Pietschnig ◽  
Michael Oeckher
Keyword(s):  
Sex Differences ◽  
Digit Ratio ◽  
Fourth Digit ◽  
Androgen Exposure ◽  
Direct Measurements ◽  
Measurement Protocol ◽  
Prenatal Androgen Exposure ◽  
The Right ◽  
Putative Marker ◽  
Prenatal Androgen

Different methods for measuring the second-to-fourth digit ratio (2D:4D), a putative marker for prenatal androgen exposure, may lead to varying values of 2D:4D. Specifically, it has been hypothesized that fingertip fat pads may be differentially deformed when taking palm images (photocopies or flatbed scans), but not when fingers are measured directly, thus yielding lower 2D:4D values from image-based measurements rather than direct ones. A measurement protocol for fingertip size is unavailable, as are data on finger and sex differences in this trait. Introducing such a protocol, this study found very large finger differences in adult fingertip size (largest for 4D, smaller for 3D and 5D, smallest for 2D), large side differences (larger in the left than in the right hand of right-handed subjects), but only small and not significant sex differences. Fingertip size was unrelated to image-based 2D:4D measurements, suggesting that fingertip size and the extent of finger and sex differences therein are unlikely to explain discrepant 2D:4D values obtained from image-based versus direct measurements.

scholarly journals Investigating the reliability and sex differences of digit lengths, ratios, and hand measures in infants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luisa Ernsten ◽  
Lisa M. Körner ◽  
Martin Heil ◽  
Gareth Richards ◽  
Nora K. Schaal
Keyword(s):  
Sex Differences ◽  
Measurement Techniques ◽  
Directional Asymmetry ◽  
Computer Assisted ◽  
Sexually Dimorphic ◽  
Digit Ratios ◽  
Androgen Exposure ◽  
Prenatal Androgen Exposure ◽  
Test Retest Reliability ◽  
Prenatal Androgen

AbstractHands and digits tend to be sexually dimorphic and may reflect prenatal androgen exposure. In the past years, the literature introduced several hand and digit measures, but there is a lack of studies in prepubertal cohorts. The available literature reports more heterogeneous findings in prepubertal compared to postpubertal cohorts. The comparability of the available studies is further limited by the study design and different measurement techniques. The present study compared the reliability and sex differences of available hand and digit measures, namely digit lengths of 2D, 3D, 4D, 5D, digit ratios 2D:4D, 2D:5D, 3D:4D, 3D:5D, 4D:5D, relative digit lengths rel2, rel3, rel4, rel5, directional asymmetry of right and left 2D:4D (Dr-l), hand width, length, and index of 399 male and 364 female 6-month-old German infants within one study using only indirect and computer-assisted measurements. The inter-examiner reliability was excellent while the test-retest reliability of hand scans was only moderate to high. Boys exhibited longer digits as well as wider and longer hands than girls, but smaller digit ratios, with ratios comprising the fifth digit revealing the largest effect sizes. Other hand and digit ratios revealed sex differences to some extent. The findings promote the assumption of sexual dimorphic hand and digit measures. However, by comparing the results of the available literature, there remains an uncertainty regarding the underlying hypothesis. Specifically in prepubertal cohorts, i.e. before the influence of fluctuating hormones, significant effects should be expected. It seems like other factors than the influence of prenatal androgens contribute to the sexual dimorphism in hand and digit lengths.

EVIDENCE FOR ASSORTATIVE MATING ON DIGIT RATIO (2D:4D), A BIOMARKER FOR PRENATAL ANDROGEN EXPOSURE

2007 ◽  
Vol 39 (4) ◽  
pp. 599-612 ◽  
Author(s):  
MARTIN VORACEK ◽  
STEFAN G. DRESSLER ◽  
JOHN T. MANNING
Keyword(s):  
Assortative Mating ◽  
Age Differences ◽  
Research Programme ◽  
Digit Ratio ◽  
Left Hand ◽  
Right Hand ◽  
Androgen Exposure ◽  
The Right ◽  
Prenatal Androgen ◽  
Spousal Similarity

SummaryThe second-to-fourth digit ratio (2D:4D) presents an anatomical sex difference in humans. On average, men tend to have lower 2D:4D compared with women. There is fairly strong evidence for a role of the 2D:4D ratio as a biomarker for the organizational (permanent) effects of prenatal testosterone on the brain and behaviour. Recently, an accumulating research programme has shown 2D:4D to be related to a multitude of sex-dependent, hormonally influenced biosocial traits and phenotypes which reach into the domains of ability, behaviour, fertility, health, personality and sexuality. This study investigated the degree of assortative mating (spousal similarity) in a sample of 239 native Austrian couples of parental or grandparental age, all of them having reproduced. Results included: (i) significant spousal correlations of +0·19 and +0·18 for right-hand and left-hand 2D:4D, respectively, and +0·24 for average 2D:4D; (ii) no assortative mating effect on the right-minus-left difference in 2D:4D; (iii) indications consistent with a possible generational decrease of spousal similarity in 2D:4D; (iv) a prevalence of couples with a lower right-hand 2D:4D observed in the husband compared with his wife; and (v) relations of spousal 2D:4D patterns to spousal age differences, such that matings of men with more male-typical trait expressions (namely, a generally low right-hand 2D:4D or showing a lower right-minus-left 2D:4D difference than their wives) implicated larger male-minus-female age differences, i.e. younger wives. It is argued that assortative mating on 2D:4D operates indirectly and may be mediated through the assortment on other, more perceptible, physical traits and psychological phenotypes that entertain associations with 2D:4D and are relevant for courtship and mate choice.

Scientometric Analysis and Bibliography of Digit Ratio (2D:4D) Research, 1998–2008

2009 ◽  
Vol 104 (3) ◽  
pp. 922-956 ◽  
Author(s):  
Martin Voracek ◽  
Lisa Mariella Loibl
Keyword(s):  
Digit Ratio ◽  
Scientometric Analysis ◽  
Total Citation ◽  
Androgen Action ◽  
Incomplete Coverage ◽  
Citation Bias ◽  
Meta Analyses ◽  
Putative Marker ◽  
Prenatal Androgen ◽  
First Time

A scientometric analysis of modern research on the second-to-fourth digit ratio (2D:4D), a widely studied putative marker for prenatal androgen action, is presented. In early 2009, this literature totalled more than 300 publications and, since its initiation in 1998, has grown at a rate slightly faster than linear. Key findings included evidence of publication bias and citation bias, incomplete coverage and outdatedness of existing reviews, and a dearth of meta-analyses in this field. 2D:4D research clusters noticeably in terms of researchers, institutions, countries, and journals involved. Although 2D:4D is an anthropometric trait, most of the research has been conducted at psychology departments, not anthropology departments. However, 2D:4D research has not been predominantly published in core and specialized journals of psychology, but rather in more broadly scoped journals of the behavioral sciences, biomedical social sciences, and neurosciences. Total citation numbers of 2D:4D papers for the most part were not larger than their citation counts within 2D:4D research, indicating that until now, only a few 2D:4D studies have attained broader interest outside this specific field. Comparative citation analyses show that 2D:4D research presently is commensurate in size and importance to evolutionary psychological jealousy research, but has grown faster than the latter field. In contrast, it is much smaller and has spread more slowly than research about the Implicit Association Test. Fifteen conjectures about anticipated trends in 2D:4D research are outlined, appendixed by a first-time bibliography of the entirety of the published 2D:4D literature.

Association between Hand Digit Ratio (2D:4D) and Nonsyndromic Orofacial Clefts

2017 ◽  
Vol 54 (5) ◽  
pp. 595-601
Author(s):  
Costa Mendes Patrícia Helena ◽  
Barbosa Camila Reis ◽  
Miranda Esteves Da Silva Myriam Thatyana ◽  
Ribeiro Paranaíba Lívia Máris ◽  
Barbosa Martelli Daniela Reis ◽  
...  
Keyword(s):  
Cleft Lip ◽  
Ring Finger ◽  
Specific Pattern ◽  
Digit Ratio ◽  
Orofacial Clefts ◽  
Significance Level ◽  
Significant Difference ◽  
And Gender ◽  
Student’S T ◽  
The Right

Objectives Digit ratio (2D:4D) has been considered to be a marker in studies evaluating an individual's susceptibility to diseases, especially those diseases that show sex differences in their occurrence. We aimed to assess whether 2D:4D ratios are associated with nonsyndromic cleft lip and/or palate (NSCL/P) and verify the existence of a specific pattern of 2D:4D ratio in individuals affected by orofacial clefts. Design This was a case-control study. Methods Digital measurements of index and ring finger lengths of both hands of patients with NSCL/P (n =54) and age- and gender-matched controls (n = 54) were obtained using a digital vernier caliper. Mean ratios between the second and fourth digits were compared. Data were analyzed by Student's t test and Mann-Whitney test with a significance level of 5%. Results No significant difference was found between the mean digit ratios of the right and left hands between the groups for any analysis ( P > .05), neither for the whole sample nor for the distributions by type of cleft and by gender. Conclusions Although the development of the fingers and the occurrence of NSCL/P can be regulated by the actions of similar genes, our results are not consistent with an association between 2D:4D ratio and this craniofacial deformity. This suggests that intrauterine exposure to fetal androgens, assessed using this marker, is similar between patients with NSCL/P and healthy individuals. We highlight the need for further studies in populations with different ancestries.

scholarly journals Digit ratio (2D:4D) and amniotic testosterone and estradiol: an attempted replication of Lutchmaya et al. (2004)

2021 ◽  
pp. 1-6
Author(s):  
Gareth Richards ◽  
Wendy V. Browne ◽  
Mihaela Constantinescu
Keyword(s):  
Amniotic Fluid ◽  
Digit Ratio ◽  
Second Trimester ◽  
Left Hand ◽  
Digit Ratios ◽  
Hormone Exposure ◽  
The Right ◽  
Digit Length ◽  
Attempted Replication

Abstract The ratio of length between the second (index) and fourth (ring) fingers (digit ratio or 2D:4D) is frequently employed as a retrospective marker of prenatal sex hormone exposure. Lutchmaya et al. (2004) reported that the ratio of testosterone (T) to estradiol (E) present in second-trimester amniotic fluid was negatively correlated with digit ratios for the right hand (but not the left hand) in a sample of 29 children at 2-year follow-up. This observation is frequently cited as evidence for the measure’s validity but has not been replicated. We therefore present the findings of another study of amniotic T and E that did not find evidence for these effects at 4½-year follow-up. The confidence intervals were large, the direction of correlations observed was generally erratic, and the overall findings question the premise that second-trimester sex hormones affect the development of digit length ratios in humans.

scholarly journals Digit Ratio (2D:4D) and Amniotic Testosterone and Estradiol: An Attempted Replication of Lutchmaya et al. (2004)

2020 ◽  
Author(s):  
Gareth Richards ◽  
Wendy V. Browne ◽  
Mihaela Constantinescu
Keyword(s):  
Amniotic Fluid ◽  
Digit Ratio ◽  
Second Trimester ◽  
Left Hand ◽  
Digit Ratios ◽  
Hormone Exposure ◽  
The Right ◽  
Digit Length ◽  
Attempted Replication

AbstractThe ratio of length between the second (index) and fourth (ring) fingers (digit ratio or 2D:4D) is frequently employed as a retrospective marker of prenatal sex hormone exposure. Lutchmaya et al. (2004) reported that the ratio of testosterone (T) to estradiol (E) present in second trimester amniotic fluid was negatively correlated with digit ratios for the right hand (but not the left hand) in a sample of 29 children at 2-year follow-up. This observation is frequently cited as evidence for the measure’s validity but has not been replicated. We therefore present the findings of another study of amniotic T and E that did not find evidence for these effects at 4½-year follow-up. The confidence intervals were large, the direction of correlations observed was generally erratic, and the overall findings therefore question the premise that second trimester sex hormones affect the development of digit length ratios in humans.

scholarly journals Assessment of 2D:4D ratio for the early diagnosis of caries and malocclusion in 7-15-year-old children

2021 ◽  
Vol 20 (1) ◽  
pp. 154-158
Author(s):  
Rakhi Issrani ◽  
Fahad Aljohani ◽  
Namdeo Prabhu ◽  
Mohammad Khursheed Alam
Keyword(s):  
Medical Science ◽  
Ring Finger ◽  
Open Bite ◽  
Age Group ◽  
Deep Bite ◽  
Anterior Crowding ◽  
Left Hand ◽  
Posterior Crossbite ◽  
The Right ◽  
Digit Length

Background: The ratio between 2nd and 4th digit length is termed as hormonal fingerprintand is used as an indirect marker in many medical diseases.Dental studies pertaining to theimportance of hormonal fingerprint on oral health are very sparse. Aim and objectives: Tostudy the correlation of dental caries and malocclusion with hormonal fingerprints. Materialsand Methods: A total of 100 children of age group 7-15 years and both genders were randomlyselected and included in the present study. The hormonal fingerprint (2D:4D ratio) wasdone bymeasuring the length ratio of the index and ring finger with the help of digital vernier caliper.Caries assessment wascarried out using standard mouth mirrors and Community PeriodontalIndex probes. WHO assessment form (1997) was followed for assessment of dentitionstatus and treatment need.Occlusal characteristics evaluated were molar relation, anteriorand posterior crossbite, open bite, deep bite and lower anterior crowding. The subjects weredivided into high 2D:4D, equal 2D:4D digit ratio and low 2D:4D. All the measurements weredone by two investigators. The data collected were tabulated and statistically analyzed usingChi-square and ANOVA test. Results: Out of 100 children, 34% were males and 66% werefemales. Most of the participants were 7-8 years old (12 males and 15 females). Majority of theparticipants (87% for the right hand and 80% for left hand) had low 2D:4D ratio, only 6% forright and 11% for the left hand had high 2D:4D ratio and the remaining had equal 2D:4D ratio.Statistically insignificantcorrelation between 2D:4D ratio and deft/DMFT score and occlusalstatus of an individualwere found. Conclusion:The insignificant results of 2D:4D ratio with allthe parameters assessed validates that hormonal fingerprints could not be employed as an earlypredictor of caries and malocclusion in an individual. Bangladesh Journal of Medical Science Vol.20(1) 2021 p.154-158

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