Reminds me of this -- http://www.xtranormal.com/watch/7873033/ (cartoon version of the theory of rational addiction) -- which you'll find especially funny if you hang out with economists much.

I haven't tried crack or heroin either but I wonder if they're more addictive than alcohol or tobacco or anything else that gives instant gratification. I tend to lean toward the addictive personality viewpoint. For instance I know people who can open a bar of chocolate and eat just a square or two. If I open a bar it's all gone

The issue with crack & heroin as I understand it is the magnitude/intensity of the instant gratification. Tobacco and alcohol are definitely addictive, but the gratification is weaker.

Yes, but do you know people who can smoke crack a few times, and then forget it? Or take heroin a few times?

Yes, some personalities are more prone to addiction than others. But it's also true that some substances that give instant gratification are more addictive than others.

Yes, there are people who can smoke crack or take heroin a few times and forget it. Or play WoW for that matter. It depends on your personality.

What you say sounds right.

I wonder what, if Heroin was as freely available as alcohol or tobacco, its addiction rate would be like. It's my suspicion that drug addicts tend to come from the addictive personality subsection of the population