對異性的吸引力是天生的抑或繫於後天的因素？為什麼有些男士的吸引力好像特別大，身旁永遠不乏女伴？這些是很多人都會問的問題。若你是男士，請看看自己的手指，答案可能就在其中。

      無名指長 女性緣好
      看的是什麼？是the relative lengths of the second and fourth digits(食指與無名指相對的長度)，也是所謂"2D:4D ratio"(二指與四指比例)。當中的玄機是這樣的：
      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.
      Ring finger是戴戒指的一隻手指，即無名指，或第四隻手指。Index finger，用來指指點點那隻手指，就是食指，或第二隻手指。男性的無名指比食指長得越多，女性就會覺得他們越吸引。這是哪門子的掌相？
      這與掌相或迷信無關。這個理論絕對有科學基礎。這是有關男性在胎兒時接觸到的荷爾蒙、某些身體特質和吸引異性三者之間的微妙關係。
      Earlier studies had already shown that the size ratio between the fourth and second fingers, especially of the right hand, is a reliable indicator(可靠的指標) of the extent a man was exposed to testosterone(睪丸素) while still in the womb(子宮). The bigger the gap between a longer ring finger and a shorter index, the greater the likely impact of the hormone.
      情況基本是這樣：無名指，尤其是右手無名指越長的男性，在母親子宮內接觸睪丸素越多。這是科學界已知的現象。University of Geneva的科學家進一步研究，看看與睪丸素高有關連的身體特質，實際上是哪一種吸引女性：
      For the new study, scientists led by Camille Ferdenzi of the University of Geneva designed an experiment to find out if women are drawn to the telltale signs(揭露事實的象) of high testosterone levels in men - a symmetrical face(對稱的面容), a deeper voice, a particular body odour(體味) - who have this more "masculine"(男性化的) finger configuration(形態).
      結果發現，是symmetrical face，女性覺得最吸引。Body odour或deeper voice都不是關鍵：
      The longer the ring finger compared to the index - that is, the greater the exposure to testosterone - the more attractive the face was rated. We also found that attractiveness and symmetry in the face are highly correlated(相關連).
      Such a preference(偏好) might have evolved to boost a female's chances of reproductive success through mating with a more virile(有生殖力的、強壯的、剛健的) partner, she said.

      指長與體質行為關係
      但科學家也發現："Men with long index fingers have a lower risk of prostate cancer."(食指比無名指長的男士患前列腺癌的機會較低。)要有吸引力就要承受更高的患癌風險，如果可以選擇，不知男士會如何選擇？想了解手指長度與體質和行為的關係，可讀Digit Ratio: A Pointer to Fertility, Behavior, and Health。