Let me just use an illustration to give my input on this topic. Looking at Ronaldo and Messi, it's clear that Ronaldo built himself due to constant practice (which is like him picking up the habit) while Messi is naturally gifted (which is like footballing is in his DNA). Without much debate we know Messi is mile ahead of Ronaldo although some will disagree and that's solely due to Ronaldo's personality and respect for hard work. Now when you're born with something, you're naturally gifted in the area and it would be evident when you work on that gift.

The gambler would inherited the act is likely to be more addictive then the users that just got addicted due to some circumstances. He would picked up the habit would probably let it go if he gets an alternative to gambling but he would has a family history would die a gamble.