Verbal aggression: You may have picked it up in the womb, says new study

"A new UB study has shown that verbal aggression may have biological causes that can be identified by the ratio of length of a person's ring finger and the length of the index finger. Research on the communication trait of verbal aggressiveness, which includes behavior like name calling, ridicule, insults, racial epithets and threats, has tended to focus on its social causes...."
http://medicalxpress.com/news/2013-01-aggression-womb.html