I feel it to be a combination of both. If I am in a setting where smoking is not allowed and I wouldn't even want those with me knowing I was going to leave and have a smoke outside, I don't really feel as much of a craving to do so. Such was the case when my mother was in the hospital recently for surgery. We spent an entire day there in the hospital as it was a several hour surgery plus several more hours for recovery. Not once was I craving to go have a smoke. But if I am home alone on the computer and run out of smokes, I can barely make it an hour or two before running to the store to pick up another pack. When I am trying to get work done at my computer and don't have any cigarettes on hand, I cannot concentrate on what I am doing.