The digit ratio is the ratio of the lengths of different digits or fingers typically measured from the bottom crease where the finger joins the hand to the tip of the finger. It has been suggested by some scientists that the ratio of two digits in particular, the 2nd (index finger) and 4th (ring finger), is affected by exposure to androgens e.g. testosterone while in the uterus and that this 2D:4D ratio can be considered a crude measure for prenatal androgen exposure, with lower 2D:4D ratios pointing to higher androgen exposure. The 2D:4D ratio is calculated by dividing the length of the index finger of the right hand by the length of the ring finger. A longer index finger will result in a ratio higher than 1, while a longer ring finger will result in a ratio of less than 1.
The 2D:4D digit ratio is sexually dimorphic: while the second digit is typically shorter in both females and males, the difference between the lengths of the two digits is greater in males than females.
A number of studies have shown a correlation between the 2D:4D digit ratio and various physical and behavioral traits.
Read more about Digit Ratio: History of Digit Ratio Research, Digit Ratio Distribution, Evidence of Androgen Effect On Digit Ratio, Explanation of The Digit Ratio Effect, Geographic and Ethnic Variation in 2D:4D, Correlation Between Digit Ratio and Traits, Digit Ratio and Palaeolithic Hand Stencils, Digit Ratio Research in Animals
Famous quotes containing the words digit and/or ratio:
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—Herman Melville (1819–1891)
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—John Jay Chapman (1862–1933)