Health test: How finger lengths may point to disease susceptibility
The Oregonian, Portland, Ore.
April 05--If you have an index finger shorter than your ring finger, your athletic performance is likely better than average. You may come across as aggressive. And you may be more susceptible to attention deficit disorder, autism, arthritis, and certain cancers -- including prostate cancer in men.
Nobody knows for sure why finger length shows these statistical links with life habits and disease risks. Some researchers believe the explanation lies with exposure in the womb to higher levels of testosterone, the so-called male sex hormone. The level of testosterone relative to estrogen plays a leading role in sexual development. It also influences less obvious differences in the brain, body metabolism and finger length.
Test yourself: Keep in mind that the link between finger length and prenatal hormone stimulation isn't strong enough to predict with certainty how life is going to turn out for a particular individual. For now, most researchers think the ratio is best used to compare populations to test how hormones may act early in fetal development. It may eventually be an indicator of risk for some health problems, but it's not generally accepted yet.
Here's how to calculate where you fall on the spectrum of finger length:
1. Measure from the tip of the finger to the crease where it meets the palm. Be as precise as you can; measure to the nearest eighth of an inch or finer. (You can use millimeters.
2. Divide the length of the index finger by the length of the ring finger. (Called the 2D:4D ratio -- scientists consider the thumb the first digit, the index finger second and the ring finger fourth.)
The index finger tends to be a bit shorter than the ring finger in men, while the two fingers tend to be equal in length in women. The differences are slight. In one large study, the average ratio of index to ring finger length was 0.98 in men and 1.0 in women.
Women and men with ratios less than 1 were significantly more likely to develop arthritis than those with ratios equal or greater than 1, in one study. Men with ratios greater than 1 appeared to gain a small measure of protection from developing prostate cancer, in another study.
Women with ratios lower than 0.97 were significantly more likely to be accomplished athletes than women with higher ratios. In a study of stock and bond traders, the highest-earning men had an average ratio of 0.93. The lowest earners had an average ratio of 0.98.
-- Joe Rojas-Burke; follow me on Twitter
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