There was an excellent episode of Radiolab about this subject. If you have the time or inclination to listen to an hour long podcast, I highly recommend "Words"

There was an excellent episode of Radiolab about this subject. If you have the time or inclination to listen to an hour long podcast, I highly recommend "Words": http://www.radiolab.org/2010/aug/09/ http://www.radiolab.org/2010/aug/09/