Sure, smoking can be considered as a social habit. But you can say the same of any drug. If it was only the social part which was important, you shouldn't have

Sure, smoking can be considered as a social habit. But you can say the same of any drug. If it was only the social part which was important, you shouldn't have any problem starting a new habit of taking a break for another arbitrary reason (go for some fresh air, glass of water, just want to take a break, etc.). This type of break can work, but it's definitely not going to have as much success as would a smoke break. Hence I say that the mean reason for those breaks was not social interaction, the social was just a side effect (albeit a pleasant one).