I just found this tidbit...Finger size ratio relates to verbal aggression
If you fly off the handle easily, check your fingers. The ratio of relative finger length may indicate a greater tendency for verbal aggression in adults, according to new research published in the Journal of Communications (Oct. 2012). In two studies, researchers measured the ratio of length of the index finger (2D) to the length of the ring finger (4D) of more than 600 volunteers. Those with a smaller 2D:4D ratio reported more verbal aggression behaviors than those with higher ratios.
"This difference relates to the exposure and receptivity of the fetus to testosterone in the womb," said Allison Shaw, PhD, assistant professor in the communication department at the University at Buffalo–State University of New York. Prior research also shows a link between this finger ratio and dominance, athletics and memory as well as physical aggression. "Keep in mind, however, that the amount of variation is so small — to hundreds of decimal places in millimeters — that it's really difficult to just look at someone's hands and predict who's going to be aggressive or not," said Shaw. So don't blame your fingers for your short temper.