My sister and I have had this discussion. My oldest daughter and I have had this discussion.
My sister chose, due to what she saw with my mom and her own dad's history of addiction, to not even tempt fate. She and her husband decided early on to not have alcohol in the house. She's had other struggles though with E.D.'s that can be classified along the addiction spectrum.
My oldest has asked me if it's genetic. I tell her I don't know. I really don't. She has also chosen to not have alcohol a part of her life (she also has the disease where drinking would be very very bad, so that's always a safety measure in place for her).
I do believe in the environment link strongly. While my mom quit drinking when I was 5, I still have very clear memories of going to the bar with her during the day and playing video games and having Shirley Temples. I remember the parties where I was the little waitress and would get quarters for bringing drinks. I remember her hangovers, the people coming over, the chaos. But I never had a fear of alcohol. Ever. To me, it was just something you did. Even though, now as an adult, I connect those bad times with her drinking, most of my memories going into my teens were people laughing, playing music, having drinks, and so associated it with a good time. Drinking = fun for me. However, I can look back now and realize I never drank like other people I was a binger from the get-go. That may be the hereditary link. I don't know. I don't fret it much because the end result is the same: I don't drink anymore. It's bad for me.
Something my sister said has always stuck with me "I don't drink because I don't want to trip a trigger and find out if I have it in me to be alcoholic. So I just avoid it" Smart thinking and does come down to no matter our genetics or how we grew up, we have the choice in the end whether we drink or not.