In my son's school, he is 7 1/2 and whole grade accelerated to 3rd grade. However, he is only the youngest by 4 months, based on our district's December cutoff. There is a very wide range of ages in his class from him to the oldest who will turn 10 in January (retained). I figure at best, we are encountering any social/ cultural issues 6 months ahead of his age-mates. I doubt by the time he's in middle or high school those 6 months will make much difference.
We will have to push for subject acceleration by middle school and I do worry about it then. He will likely be in a math class with kids 4-5 years older. That's a dramatic jump.
