The argument for lowering the drinking age to 18 goes like this: They're old enough to fight and die for our country, to vote, buy cigarettes and serve on a jury. Under the law, they're adults. So why can't they drink?

If only it were that simple. Ever wonder why Texas law doesn't allow anyone under 21 to obtain a concealed-weapon permit or why car rental companies reject renters under 21?

It's not just age but maturity that defines adulthood. And there's a far greater assurance that 21-year-olds are closer to the level of mature responsibility – including the ability to restrain impulsive behavior – that must be required of people who drink.

More than 100 college and university presidents last month called for a national discussion about lowering the legal drinking age. They argued that depriving 18- to 21-year-olds legal access to booze contributes heavily to binge drinking. Legalizing access, they say, would encourage drinking in moderation.

The fact that university presidents are making this argument should not be confused with scholarly research. University administrators face enormous legal liabilities when underage drinking occurs on their watch. A lower drinking age would certainly ease universities' legal burden, but evidence is scant that it would reduce binge drinking.

British lawmakers used the same rationale in 2005 to relax laws requiring pubs to close at 11 each night. Proponents argued that with later closing times, patrons would be less likely to binge-drink to beat the clock. But British officials concede the experiment has failed. If anything, officials say, the problem has gotten worse.

Scholarly studies abound about why lowering the drinking age is a bad idea, including several showing a direct correlation between alcohol-related traffic fatalities and lower drinking ages.

The real solution is a cultural one – valuing moderation and stigmatizing excess. But until that happens – and as long as all-night keggers and Jell-O shot competitions are the rage – the current law is exactly where it needs to be.