In "Duels and Duets," John L. Locke, a professor of linguistics at Lehman College and the author of "Eavesdropping: An Intimate History," argues that men and women have radically different ways of speaking not because of their upbringing, but because they have radically different evolutionary needs. Men, he argues, use antagonistic speech, or "duels," to show off their strength and prove themselves to women.Women, meanwhile, use quieter speech patterns to bond with each other and help protect themselves against aggressive men.And, according to Locke, this is a pattern that has been going on for thousands and thousands of years.