I have obviously simplified the role of dopamine in the brain to make it more digestible, but you are dead wrong about dopamine’s role in intermittent reward and the link to gambling addiction. It has a very strong influence on behavior. Like many aspects of human behavior, the effect is not an on-off switch to enable gambling addiction. We have lots of things going on in our head that are, at times, working against each other as far as behavior is concerned. It is more like an analog adjustment that “pushes” toward a specific behavior much harder than it otherwise would. And this effect is just as powerful as addictive chemicals in potency.