Strange as it might seem, the shorter a man's index finger is compared to his ring finger, the more inclined he is to be physically aggressive. Psychologist Dr. Peter Hurd at the University of Alberta measured the fingers of 300 students and asked them to answer a questionnaire on aggression. He found that finger lengths did correlate to physically aggressive behaviour. Scientists believe that the more testosterone -- which is secretd naturally by the mother -- a male foetus is exposed to in the womb, the shorter his index finger will be. The same is not true for female foetuses.

"You wouldn't want to screen people for certain jobs based on finger lengths," says Dr. Hurd, "but we are learning that a large part of our personality is determined while we're in the womb.

Learn more about the effects of the length of your fingers on your personality here.