• Publications
  • Influence
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. Expand
Digit Ratio: A Pointer to Fertility, Behavior, and Health
Sex and Population Differences * Associations with Testosterone and Estrogen * Assertiveness, Aggression, Attractiveness, and the Wearing of Rings * Reproductive Success and Sexually AntagonisticExpand
2nd to 4th digit ratios, fetal testosterone and estradiol.
Preliminary findings lend support to an association between low 2D:4D and high levels of FT relative to FE, and high 2D-4D with low FTrelative to FE. Expand
Second to fourth digit ratio and male ability in sport: implications for sexual selection in humans.
  • J. Manning, R. Taylor
  • Psychology, Medicine
  • Evolution and human behavior : official journal…
  • 2001
It is suggested that prenatal and adult testosterone promotes the development and maintenance of traits which are useful in sports and athletics disciplines and in male:male fighting. Expand
The second to fourth digit ratio and variation in the androgen receptor gene
It is shown in a sample of 50 men that 2D:4D is a phenotypic correlate of AR structure, and right-hand 2D-4D was positively correlated with CAG number and individuals with low 2D:[4D]4D in their right hand compared to left hand had AR alleles with low CAG numbers. Expand
The Effects of Sex, Ethnicity, and Sexual Orientation on Self-Measured Digit Ratio (2D:4D)
We used self-reported direct finger measurements from 255,116 participants in a BBC Internet survey to investigate the measurement of 2D:4D ratios and their association with sex, ethnicity, andExpand
Digit ratio (2D:4D), dominance, reproductive success, asymmetry, and sociosexuality in the BBC Internet Study
  • J. Manning, B. Fink
  • Biology, Medicine
  • American journal of human biology : the official…
  • 1 July 2008
The BBC Internet Study of sex differences in which finger lengths were self‐measured shows sexual dimorphism, ethnic differences and higherDimorphism of right 2D:4D than left, thereby indicating that 2D-4D does measure real between‐participant variation. Expand
The 2nd to 4th digit ratio and autism.
2D:4D ratio may be a possible marker for autism which could implicate prenatal testosterone in its aetiology and positive associations of children with autism and the ratios of their relatives were found. Expand
Hand preference for writing and associations with selected demographic and behavioral variables in 255,100 subjects: The BBC internet study
It is concluded that contradictions in the literature as to whether or not these variables are linked to handedness stem largely from different definitions of hand preference, which is not normally available for analysis. Expand
The ratio of 2nd to 4th digit length and performance in skiing.
  • J. Manning
  • Medicine
  • The Journal of sports medicine and physical…
  • 1 December 2002
Low 2D:4D in skiers compared to controls suggests the former are more andogenised than the latter, and could be used to help identify young skiers who have potential to reach high levels of performance. Expand