The longer a man's fourth or ring finger is compared to his index finger, the more likely he is to be judged attractive by women

The results unveil intricate links between fetal exposure of males to hormones, the development of certain physical traits, and what turns on the opposite sex. It also adds to a growing body of research - conducted under the banner of evolutionary psychology - suggesting that the drivers of human behavior are found, more than previously suspected, in "nature" rather than "nurture." Earlier studies had already shown that the size ratio between the fourth and second fingers, especially of the right hand, is a reliable indicator of the extent a man was exposed to testosterone while still in the womb. The bigger the gap between a longer ring finger and a shorter index, the greater the likely impact of the hormone. The ring-index finger ratio has also proven to be a useful indicator for gauging the risk of prostate cancer, likewise tied to high levels of testosterone. Research shows that the chances of developing the disease drop by a third in men whose index finger is longer than their ring finger. Other studies have also found a link between exposure to hormones before birth and the development of other diseases, including breast cancer and osteoarthritis.