A willingness to accept risk is a healthy expression of our need to grow, change, solve problems, help ourselves and others. Even people who bet regularly, but not excessively - so-called social gamblers - are as well adjusted as nongamblers, studies show. Social gamblers are people who can "take it or leave it."
Getting high on risk, much like getting high on drugs or alcohol, is at the heart of compulsive gambling. Win or lose, the compulsive gambler craves the action. As one put it, "I don't feel alive unless I am gambling."
In the 1950's, behaviorist B. F. Skinner's experiments with pigeons showed that persistence (addiction) develops when reinforcement (winning) is so variable as to be unpredictable. Almost all compulsive gamblers have had at least one big win and believe they're bound to have another - soon.