i realized my DS6 had an improper grip this past fall. he is right handed but has his hand/arm in a lefty position. i couldn't believe i hadn't noticed it before! i found out the kid next to him in class was a lefty!!! i think DS was modeling! the teacher never noticed either. then again, she really didn't care.
Interestingly arm/body position in writing tends to be representative of actual hemispheric dominance in language use. In that a "normal position" represents language in the opposite hemisphere from the writing hand; whereas the hooked arm position tends to represent language in the same hemisphere as the writing hand. Mis-modeling could be a factor too.
As to "too late to learn correct grip," I learned the correct writing grip at 35. I saw an illustration in a book and realized I'd had my thumb over my index finger my whole life rather than on the pencil. Some minor cursing on my part at teachers who had issues with my writing but never taught me a correct grip. It took me a few years to absorb the new grip, and when tired I still slip back.
