The Effects of Sex, Ethnicity, and Sexual Orientation on Self-Measured Digit Ratio (2D:4D)

@article{Manning2007TheEO,
  title={The Effects of Sex, Ethnicity, and Sexual Orientation on Self-Measured Digit Ratio (2D:4D)},
  author={John T. Manning and Andrew J. G. Churchill and Michael Peters},
  journal={Archives of Sexual Behavior},
  year={2007},
  volume={36},
  pages={223-233}
}
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, and sexual orientation. We found significant sex differences such that males had lower 2D:4D than females and the effect size of the sex differences was greatest for right hand 2D:4D. Mean 2D:4D was lower for right hands than for left hands in men, but lower for left hands compared to right hands in women… 
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It was found that the regression of 2D on 4D showed sex differences in slope, and such differences gave rise to the sexual dimorphism in 2D:4D.
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