This is an interesting question that I've pondered, as well. I was on the phone recently with a drug and alcohol resource line, and the woman I talked to said that there was a study with mice that possessed certain genes and that they were attracted to some while the other mice were not. However, she said that when the other mice were injected with alcohol on a regular basis, they developed the same attraction to alcohol. So, this seems to suggest that one can become alcohol addicted no matter what their genetic makeup. I think it makes sense that there are a variety of triggers, but that anyone could potentially become "alcoholic" if exposed to the substance long enough.