I checked the web and found only one other usage of the expression, “north and south nod”. Here, from the marinatedministries.org web site, is what I found:
I wanted to give to my child some meaningful, yet, productive information so I said, "sit down child, I have to give a meaningful speech." My child sat down and I began to teach. These are the Do's and the Don'ts of life, [sic] after finishing I asked, "Do you understand?" The North and South nod of the head said you did well, Dad.
Here the usage seems to indicate that the person nodding, in addition to understanding what was said, agrees with what was said too. There is, of course, a possibility that the author of the above story isn’t sure of what the expression really means either.
Physically speaking, if one considers the head to have a north and a south, the top of the head would logically be north, and the chin would be south. A subdued up and down nod would not, in my mind, be aptly described by the phrase “north and south”. An up and down nod with exaggerated movement, i.e. the head going higher up and lower down than a normal nod, would be more in keeping with the “north and south” description. Perhaps the north and south nod is more indicative of blank agreement without understanding, or perhaps understanding with mocking agreement.
If the description “north and south” is descendant from the times of US Civil War, perhaps “north and south” originally referred to one with dual sympathies, i.e. one who was non-committal. This might explain the “non-committal” element found in General Garner’s comments.
