I think that the dopamine deficient,( ADD, ADHD ), are more likely to enjoy gambling. As others have said there are different types of gamblers : I consider poker to primarily be a game of skill with a gambling element. Just as about 10ish% percent of people who drink alcohol will develop a problem, I would say the percentage is about the same for problem gamblers. One of the main reasons I quit playing poker for a living in 2009 was the realization that I was making my living off gambling addicts....