I'm starting a new thread on a sub-thread developed over in Q&A's "Mongrel Pronunciations":

There, Sparteye brings up one Dr Tsunoda's research on the brain. He's quoted as saying, "I believe that the mother tongue differenciates the way in which people receive, process, feel, and understand sounds in the external environment.... The mother tongue is closely related to the development of the emotional mechanism in the brain. I conjecture that the mother tongue acquired in childhood is closely linked with the formation of the unique culture and mentality of each ethnic group."

There's nothing new here. As early as 1929, Edward Sapir fomulated the same hypothesis: "We see and hear ... very largely as we do because the language habits of our community predispose certain choices of interpretation."

What do y'all think?

Also, in the January Smithsonian magazine (the folks who brought you Anu Garg in December) there is a piece on language acquisition called "Accents Are Forever." It's pretty widely accepted that a foreign language learned after puberty is learned imperfectly (Noam Chomskey did pioneer work on this theory at MIT). Patricia Kuhl of the Univ. of Washington goes a step farther and suggests that "By their first birthday, babies are getting locked into the sounds of the language they hear spoken."

http://www.smithsonianmag.si.edu/smithsonian/issues01/jan01/phenom_jan01.html