I can only write this based on my own personal experiences as a victim of an alcoholic. I have given it a lot of thought but before writing on this subject I have not researched the matter as I want this to be solely based on experience.
Jane (not her real name), my partner, is an alcoholic. She is a binge alcoholic. This means every 3 weeks, more or less, she takes to the bed and drinks neat Vodka out of the bottle at the rate of one large bottle (70 cl or 1 liter) per day (plus a bit more sometimes) for a period of about 4-10 days. She remains in bed when doing this. She sleeps or dozes throughout the experience.
In between binges she drinks in the evening sometimes but this is not done in front of me. She nearly always drinks neat Vodka and always secretly even though I can tell when she is drinking and she knows that I know.
I can say with some certainty that alcoholism is to an extent genetic based, meaning the propensity to it is inherited.
This is because an observation of her family (the female side in this case) indicates this. Her mother is bordeline (in my view) anorexic and her sister is the same (as is Jane). This may of course be trained in from childhood and I think in part it is but the more obvious connection would be genetic.
Anorexia is a condition about which little is still known. But in my experience it is associated with low self esteem, lack of confidence, anxiety and depression. This bundle of elements also accompany alcoholism and drug addiction (i.e. mental health issues).
We have then a personality that has a predisposition to alcoholism. If a mother has a character that is predisposed to alcoholism she may also have a character that is not ideally suited to parenthood. This may (and I would say has in Jane's case) lead to an early childhood for the offspring that is not ideal.
In Jane's case I think her childhood experiences (arguing parents and a cold mother) increased her chances of developing alcoholism in later life, when the pressures of life pushed her towards it.
There is a natural intertwining of genetic make up and behavior (Parent to child - originating in the genetic mak up) that results in acoholism.
Photograph reproduced under creative commons copyright Greg Maslowski