Not saying you're wrong, but I don't believe their is any genetic tie to nicotine addiction. Not saying it's not addictive, it clearly is, but it is more of a self-induced addiction. Same for caffeine, which is something I deal with. When I worked nights, I would drink a pot of coffee, literally, at work. Then come home and sleep for 3 or 4 hours, get up and watch my son all day, drinking coffee because I needed to stay awake. I probably drank 18-20 cups in an average 24 hour period. Tried to stop, felt like I was stuck in quicksand all day, groggy, headaches, crabby. Caffeine is nasty stuff. Now I'm down to 2(big) cups in the morning, and sometimes 1 more after work.
The thing about smoking is that it's kind of a learned behavior. If everyone in your family smokes, you see it every day growing up, it's the example that's been set for you, and in turn you pick it up just because. From that point on it becomes addictive, but there is no pre-disposition to it. In my wife's family, everyone smoked or smokes, except her, thank god. Dad, Mom, stepfather, brothers. She of course was the one to get breast cancer at 33, and they've all been healthy, so go figure.
