I have been licensed for about 19 years now, and have had a few hand positions on the steering wheel I liked. 12 and 9, or just 11 and 1, or just 12. I also learned the 9 and 3, but now those who are in the know, are teaching 5 and 7. Why??? Airbags. Having your arms to the side, or above allows them to be thrown around by the airbag, down, they are simply placed into your lap.
Supposedly in Virginia... third hand info here... if your hands are not down at 5-7, you will receive at least a stern warning, or a failure depending on your attitude and or the testers day.