Judging penis size by comparing index, ring fingers
By Thomas H. Maugh II, Los Angeles Times
July 4, 2011, 11:33 a.m.

A shorter index finger may be an indicator of larger penis size.
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Men and women are what is termed sexually dysmorphic in terms of finger lengths. In women, the index and ring fingers are generally the same length, while in men the index finger is generally shorter. Researchers from UC Berkeley created a stir in 2000 when they reported that lesbian women tended to have a ratio of the two finger lengths that was more typical of men. But the situation was more complicated for men. The team found no difference in the ratio between gay and straight men unless they had several older brothers -- a factor which had previously been linked to being homosexual. Such men were found to have an unusually low ratio of the finger lengths.
Other recent research has suggested that men with a lower ratio have a more symmetrical face and are more attractive to women, a phenomenon known as the "sexy ratio." And just last year, researchers from Warwick University and the Institute of Cancer Research in Britain reported that a man's risk of developing prostate cancer is related to the ratio of the two digits. Men whose index finger in longer than their ring finger were found to be one-third less likely to develop prostate cancer.
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Penis length: Research find new way to measure penis length - latimes.com