At what age will the government give you a gun and order you to kill someone? If the government feels you're responsible enough to handle a gun and to fire said gun at people with the intents of killing them (while under orders of course) why shouldn't you have the right to buy alcohol? You can get married, have children, enter contracts, buy a home, a gun, join the military, but yet you can't purchase alcohol?
The problem really isn't a set age limit, the problem is any culture that encourages and glorifies binge drinking and also because you need to hide drinking under a certain age because it's illegal. Yet you do need to set a standard for a society to agree upon.
That being said, the other ages of consent are nominally around 18 for voting, marrying, service in the military, etc. So it should be a standard that applies for all of the abilities to act in a responsible manor without "parental" supervision.
Yet we're beginning to understand that human brain development isn't really completed until around age 25. Really grasping accountability for your actions and reigning in childlike impulse behavior. But I've met 14 year old's with more understanding of adult concepts and who act and behave that way, than some 45 year old people who still act childishly.
Not keeping a childlike sense of wonder into adult life (which is great); but greedy, selfish, rude and uncivil behavior, no comprehension of responsibility or understanding of the repercussions for your actions. This is the drag and hindrance to human societies, and necessitates the need for the setting of these 'arbitrary' age limits in the first place; but because each individual is different, actually individually determining what a persons current level of responsibility - is currently out of our societal abilities.
I think you should be able to drink at 18 if you are willing to give up guns, driving, and sex. Drinking and guns lead to shooting accidents which lead to costly emergency room visits and sometimes funerals. Drinking and driving leads to death or serious injury, most often for the pedestrian in the street or the people in the other car rather than the driver him/herself. Drunken sex leads to bad choices of sex partners, including choosing someone who is too drunk to consent to sex, and unwanted pregnancies. If you're willing to sacrifice those three things, drink all you want. If you violate those prohibitions, you get to have IDIOT tattooed on your forehead as a warning to others, in addition to any criminal consequences of your actions.
I feel that it is irresponsible for anyone under the age of 21 to be able to purchase alcohol. If the legal age was set to 18, it would encourage more underage drinking. Most seniors in high school are 18, and if they could purchase alcohol they would have more parties, and more young people would drink.
Just remember the prohibition. If we regulate anybody then it just makes the people more wanting to do it. Plus the United States is based on freedom isn't it? then why are we trying to decide people's lives for them? Drunk driving is a issue that goes beyond younger generations, all age groups do it, the real issue goes in education.
There should be no legal age limit to buying anything, but that would mean that children's parents take an active role in their upbringing and make sure their kids understand the perils and good points of what everything does.
Will it happen that parents take an active role in raising their kids?