Enter the lengths of the index and ring fingers to determine the digit index ratio. This ratio is often used in scientific studies to correlate with various biological and behavioral traits.
Digit Index Ratio Formula
The following formula is used to calculate the digit index ratio:
DIR = IL / RL
Variables:
- DIR is the digit index ratio
- IL is the length of the index finger (mm)
- RL is the length of the ring finger (mm)
To calculate the digit index ratio, divide the length of the index finger by the length of the ring finger.
What is a Digit Index Ratio?
The digit index ratio, also known as the 2D:4D ratio, is a measure of the length of a person’s index finger (second digit, 2D) divided by the length of their ring finger (fourth digit, 4D). This ratio is believed to be influenced by prenatal exposure to androgens and can vary between individuals. It has been studied in relation to various aspects of human biology and behavior, including personality traits, sexual orientation, and susceptibility to certain diseases.
How to Calculate Digit Index Ratio?
The following steps outline how to calculate the Digit Index Ratio.
- First, measure the length of the index finger (IL) in millimeters.
- Next, measure the length of the ring finger (RL) in millimeters.
- Use the formula DIR = IL / RL to calculate the digit index ratio.
- Finally, compare the calculated ratio with the average ratios known for males and females or use it in scientific research.
Example Problem:
Use the following variables as an example problem to test your knowledge.
Index Finger Length (IL) = 65 mm
Ring Finger Length (RL) = 70 mm
