Comparative Study of Digit Ratios (2D:4D and Other) and Novel Measures of Relative Finger Length: Testing Magnitude and Consistency of Sex Differences across Samples

  title={Comparative Study of Digit Ratios (2D:4D and Other) and Novel Measures of Relative Finger Length: Testing Magnitude and Consistency of Sex Differences across Samples},
  author={Martin Voracek},
  journal={Perceptual and Motor Skills},
  pages={83 - 93}
  • M. Voracek
  • Published 1 February 2009
  • Psychology, Biology
  • Perceptual and Motor Skills
Digit ratios, such as the frequently studied second-to-fourth digit ratio (2D:4D), are already sexually differentiated in utero, postnatally fairly stable, and thus commonly held as possible markers for prenatal androgen levels. Based on six independent samples, totaling 381 male and 420 female subjects from different age bands, this study investigated the magnitude and cross-sample consistency of sex differences in all six possible digit ratios (2D:3D, 2D:4D, 2D:5D, 3D:4D, 3D:5D, 4D:5D) and in… 

Sexual Dimorphism in Digit Ratios Derived from Dorsal Digit Length among Adults and Children

The present findings from three samples are consistent with the idea that early sex-hormonal effects might be stronger for digit ratios involving digit 5, as compared to the classic, and frequently studied, ventrally measured 2D:4D ratio.

No association between two candidate markers of prenatal sex hormones: digit ratios (2D:4D and other) and finger-ridge counts.

Some doubt is cast on the validity of retrospective pointers to prenatal androgen levels based on the associations of 2D:4D with finger-ridge counts, one such further under-researched marker.

Relationships of Toe-Length Ratios to Finger-Length Ratios, Foot Preference, and Wearing of TOE Rings

The majority of toe-length ratios exhibited significant sex differences, which was similar to finger- length ratios, but of weaker effect size, and among women, feminized finger-length ratio corresponded to masculinized toe- lengths, however, these associations were directionally opposite.

High 3D:5D ratio: A possible correlate of externalizing and internalizing problems: An exploratory study

The 3D:5D ratio can be considered a correlate of externalizing and internalizing problems in children from the general population.

Sexual Dimorphism of Digit Ratio (2D:4D) in Madhya Pradesh

It is suggested that the 2D:4D ratio is a constant feature among different age groups in different population, which will prove useful to determine sex when more reliable means of sex estimation are not available during medicolegal examination.

Alternative Digit Ratios and Their Relationship to Prostate Cancer.

Digit ratios in two lacertid lizards: sexual dimorphism and morphological and physiological correlates

Comparing digit ratios of two Podarcis lizards among sexes, colour morphs and species concludes that digit ratios in lizards deserve attention, because they exhibit sexual dimorphism and correlate with ecologically relevant morphological and performance variables.

Mixed Sex Effects on the Second‐to‐Fourth Digit Ratio of Túngara Frogs (Engystomops pustulosus) and Cane Toads (Rhinella marina)

Evidence for sexual dimorphism of the 2D:4D scaling relationship on the front feet of túngara frogs is found, with female frogs having a larger ratio than males resulting from a relatively longer second digit on females, and further research is needed to evaluate the effect of androgens on 2D-4D in animals other than placental mammals.



Digit Ratios (2D:4D and other) and Relative Thumb Length: A Test of Developmental Stability

These findings mirror those reported for the second-to-fourth digit ratio (2D:4D), a likely biomarker for the organizational (permanent) effects of prenatal androgens on the human brain and body, and appear to be developmentally unstable.

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

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.

Photocopies Yield Lower Digit Ratios (2D:4D) Than Direct Finger Measurements

Differences in digit ratios obtained from photocopies and direct measurements, and these differences arise from length differences recorded from the different protocols, should not be combined within one study nor should they be used together in comparative studies.

The ratio of 2nd to 4th digit length: a predictor of sperm numbers and concentrations of testosterone, luteinizing hormone and oestrogen.

It is shown that 2D:4D in right and left hands has a sexually dimorphic pattern and is probably established in utero, which raises the possibility that patterns of digit formation may relate to spermatogenesis and hormonal concentrations.

Repeatability and interobserver error of digit ratio (2D:4D) measurements made by experts

Results indicate that 2D:4D, because it is a ratio variable, is notably less precisely measurable than finger length, and one implication of this is that the marked geographical and population differences in typical 2D-4D levels, as reported in the literature, are veridical, and not due to divergent measurement habits across research groups.

Digit Ratio (2D:4D), Lateral Preferences, and Performance in Fencing

The present research tested the hypothesis that 2D:4D might be a performance indicator for men across a variety of sports and found it to be related to high performance in running, soccer, and skiing.

Hand Asymmetry in Heterosexual and Homosexual Men and Women: Relationship to 2D:4D Digit Ratios and Other Sexually Dimorphic Anatomical Traits

The present evidence actually suggests that homosexuals have lower FA than heterosexuals, raising the question of whether the positive fitness components associated with low FA may contribute to selection that maintains homosexuality in a population.