Actually, the length of your index/ring finger has to do with how much testosterone/estrogen you were exposed to as a baby (in your mother's womb.)
So, the posted graphic has it somewhat right. If your ring finger is way longer than your index, you received a lot of testosterone, and are probably rather 'manly'... If your index is longer, you received less testosterone, and are probably less 'manly'.
You can also judge with rather good accuracy who would win a physical competition (i.e. the 100 meter dash) by comparing the contestants fingers, and seeing who has the longest ring finger, as compared to their index. The longer the ring finger, the more likely you are to win (or rather have a natural advantage, training does count for something after all....
)