Those with ring fingers longer than index fingers did better on the math part of a standardized test than the reading part.

VOA: special.2009.02.25

And another British study reported last year that people whose index finger is shorter than their ring finger are at higher risk of osteoarthritis.

VOA: special.2009.02.25

A way to know how much is to compare their ring finger to their index finger.

VOA: special.2009.02.25

Overall, therefore, men tend to have longer ring fingers than index fingers, whereas in women the two fingers are more likely to be of equal length.

ECONOMIST: Autism

The main control surface is wide enough, in fact, that we could comfortably put three fingers on the top of the mouse, using the middle to control the mouse wheel and DPI sensitivity adjustment rocker (a nice touch in and of itself) without ever moving our index and ring finger from the all-important trigger buttons.

ENGADGET: Exclusive: Mad Catz Cyborg Rat 9 review

Dr Manning and Dr Baron-Cohen found that autistic children had extremely long ring fingers compared with their index fingers.

ECONOMIST: Autism