Well, my point with bringing up personal is that it seems like we would have a different standard for decisions which effect primarily the person who makes them and decisions which effect society as a whole. It's like we say "well, your 18, if you want to smoke they are your lungs". But I would think we would automatically have higher expectations for someone who would be making that decision for everyone.

I guess a good example is the age limit for president (35). Interestingly, the minimum age for House of Reps is 25. Do you think those should be set at the age of majority?