Saturday, February 19, 2011


People tend to laugh when a scientist proclaims that if the length of your index finger is longer than your ring finger your risk of prostate cancer is lower than other men. But that was recently in the news. Can it be true? What about the data? Does it substantiate such a conclusion?

Well sort of, but not very convincingly. For one thing the data are taken from men who judged their own finger lengths from pictures which showed examples of various finger lengths, and then they returned this information to the investigators by mail.

Can you imagine Grandpa looking at those finger lengths examples and exclaiming “Mine is bigger than his.” or “What did cousin Homer put on his report? I can beat him any day.” The possible sources for inaccurate measurements are endless. Feel free to make up your own and after you check out your own finger lengths send them to me for publication.

Although the whole idea of finger length and risk of prostate cancer seems almost frivolous there is some basis for the belief that there might be a relationship. It turns out that the growth and pattern of the fingers and gonads (testes and ovaries) are controlled by the same genes and that the male hormone, testosterone, may control finger length.

Therefore, it is possible that in the male fetus the testes may produce relatively high testosterone and this in turn results in a short index finger. Whereas, if testosterone were relatively low the index finger would be longer. This guess work is based on some very squeaky data from another laboratory which attempts to show that fetal testosterone is correlated with length of the index finger. These data are shown on a scatter plot which looks like Wild Bill shot it with his 12 gauge shotgun.

So, my conclusion is there may be something to the finger story but better studies need to be done before any valid conclusions can be drawn.

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