In general Americans have problems with moderation. If you say you went out to drink, then you will drink until you're drunk. While in many other countries a drink is just a drink, not even enough to get legally buzzed. If the person smoke then they smoke at least a pack a day. While in other countries it may be 1 or 2 cigarette a day.
Anecdotes are anecdotes, but as an American with a bit a world travel under my belt, this contrasts with my observations. Europeans tend to be better at the "just one drink" (and when they do over-do it, there is much better public transit, or their homes are nearby). East Asians seem to enjoy having a few drinks at a time, and Mexicans as well. There was no legal alcohol in Kuwait, and my visit to Afghanistan was before the wine "industry" started up again (so no observations there). However, the pub culture and local breweries have been taking off here in the western U.S., and we frequently go and have just one beer around here.
As to smokers: in every other country I visit, the local nationals are always surprised at how few Americans smoke. In many states in the U.S., public indoors smoking is illegal, which really cuts down on the number of chain smokers, and forces them to limit their smoking to about one cigarette per hour. I'm always surprised when I go elsewhere, as to how many people will finish a cigarette, then immediately light up another.