"Why the difference? Is it just a personality weaknesss, lack of self-control, or a genetic disposition to addictive behaviours?"

And, I might add that the same question is asked/answered in ensuing posts, but incorrectly IMO.

I answered all in my last post... it is the lack of education OR the circumstance in life or both.

If a child is taught properly by it's parents it will understand the "scourge" and avoid it unless circumstances prevail. As far as a "gene" being involved, when one considers my hypothesis, the only gene that could be considered to apply to a default situation is the "stunned as me arse gene."

Don't stick your hand in the fire as it will burn you means just that. The stupid ones will try it... and get burned. It isn't an addiction gene... it's a SAMA gene. OR it's a result of circumstance from which the person is trying to flee mentally from stress for some time with the aid of a stimulant. Unfortunately, that temporary flight from reality may be repeated "as necessary" and often results in addiction which spirals out of control.

Am I makin any sense?