Where I grew up the drinking age was 21. We drove across the state line into Kansas where the drinking age was 18 for 3.2 beer. I would have to say that this slowed down my progress in life. I would have to say that stronger alcohol might have done more damage than was done.
My father once told me that (with my children) I should establish perimeters that are smaller than what in reality I would be satisfied if they stayed in.
So in this regard, I would have to say no hard liquor until age of 21.