I have read through all of the posting here and just have a couple of observations and/or comments. Personally, I am ambivalent on the subject of lowering the gambling age to 18. But the comparison of military service to gambling is exceptional poor if not completely non-comparable. The military is a high structured environment with many layers of supervision and rigid procedures. Gambling has none of these attributes. To the best of my knowledge you are not required to go through gambling "boot camp" before being allowed to gamble. Additionally, there is no direct and constant supervision while gambling unlike in the military. Gambling is a recreational pursuit and military service is a vocation requiring a good deal of training.

I think the real question here is does a person 18 years of age have a high likelihood of possessing a maturity level that will allow that person to recognize when the recreational pursuit of gambling has become an addiction. Generally speaking, probably not, and when you are talking about changing laws you must think in generalities and what will benefit the masses. And yes, there will always be exceptions. This is why hospitals restrict small children from going into the area of a hospital where people are recovering. This is an area where there is a high likelihood that you will be exposed to a contagion. Most small children, in general, would not have time in their lives to have built up the immunities to ward off potential exposures. So to "play it safe" hospitals restrict entry.

I am sure the tobacco industry could supply copious amounts of data indication the best ages to apply a vice and achieve an addiction. I am also sure that the data would indicate that the younger the person the better the chance of achieving an addiction. Why tempt it, 21 for gambling and drinking is probably best left as is.