Your 2D:4D ratio; a revealing science activity that you can do in just a few minutes.
How to measure your 2D:4D ratio:
1. Photocopy your right hand, palm facing downwards.
2. Using the photocopy, measure the lengths of your index and ring fingers, from the crease nearest your palm to the fingertips.
3. Divide the length of your index finger by the length of your ring finger, and the number you end up with is your second to fourth digit ratio, or 2D:4D ratio.
What does it all mean? The 2D:4D ratio is thought to be a measure of the levels of sex hormones a person was exposed to when they were developing in their mother’s womb. Women typically have a ratio close to one, or ring and index fingers roughly the same length when measured. Men typically have a lower ratio, at around 0.96, from having a longer ring finger. Some people do differ from what is expected and this is thought to be a reflection of how masculinized or feminized they are.
All kinds of interesting and controversial things appear to be related to this ratio: sex, race, sexual orientation, assertiveness, autism, verbal fluency, handedness, ability at some cognitive tasks, fertility, reproductive success, musical ability, sporting ability, susceptibility to particular diseases, face shape and personality.
New Scientist magazine, 19th August 2006 page 33.
For more info:
A book review:
Scientific journal paper:
The 2nd to 4th digit ration and autism by Manning, Baron-Cohen, Wheelwright and Sanders
Developmental Medicine and Child Neurology. 2001, 43: 160-164.