Can 4 beers get a boy who is 15 drunk?

Depends on the alcohol content, how quickly it was consumed and the physical size of the drinker. Interestingly, research has indicated that the amount of alcohol required to have physical manifestations of drunkeness in teens is much higher than that of adults...so just because your kid is not acting "drunk" he could still be well lit. This explains why the parents of teen alcoholics nearly never know about it until it is too late.