Addiction of something solely depends on your temperament and your self control. Addiction is not something which immediately starts.
Attraction is the one which instigates addiction. If you can control the attraction at the earliest, you can stop it from transforming into addiction. If you think smoking is stylish and if you want to try cigarettes, it is an initial attraction that is evoking you to do that. If you control it in initial state and don't smoke the matter ends there. But if you think that you could try once and leave it later and if you smoke once, there are chances that you may not leave smoking again. The pleasure you may get at first try may evoke you to try it again and soon you become a regular user of cigarettes. Then it becomes an addiction.
So the main root for this is the second when you think of trying it once. It depends on your mind and your self control which is solely in your hands. You can make or break the habit at the very first instance and it doesn't have to do anything with the genes or anything about whether your father or grand father smoke. This is a good example to say that addiction is not genetic.
As far as the genes are concerned, genes transfer only the physical characters to the next generation and they don't have to do anything with psychological feelings or characters. There is no way that the mental characters transfer through genes.
But we might have seen some people who are drug addicts and whose parents are also drug addicts. Such people makes our doubts about whether drug addiction is genetic stronger. Butr there is a reason for this abnormality. In normal cases, parents tell children that drugs are bad and one should not use them. But in the case of drug addicts, they don't say that drugs are bad and besides this they can not control themselves from taking drugs. This makes these people be unconscious and take pleasure in drugs infront of their children. This makes the children doesn't develop a conscience that the drugs are bad and in fact they may develop some curiosity about drugs.
This evokes the children in the drug addict's house to try drugs and it slowly becomes an addiction to them. Thus it makes some people think that drug addiction is genetic.
So, drug addiction is in no way genetic and it depends solely on your capacity to control the curiosity inside you.
