I love the way the author in Sil's first link says "All knitters hold the needles the same way." NO THEY DONT!
The President of my organization is a 78 YO British Lady. She and I flew on a business trip together & it PAINED her to watch the way I held my needles.
She holds hers (at least the right one) like a pencil. She made me try it....my hands would NOT stay that way. It was like I had no control over my hands.