When we are rewarded for doing something, we are more likely to do it again. Children may learn from their parents that after they eat their vegetables they'll get dessert, and if they make their bed they can watch television. Contingency management — behavioral psychology supplies the language — is a systematic and consistent use of this principle, especially in the treatment of drug and alcohol abusers and children with behavior problems.
"Contingency" means that a reward is contingent on performing a desired act. "Management" is the art, science, or practice of arranging these rewards to shape behavior. In behavioral terms, use of a drug like alcohol, heroin, or cocaine is an unconditioned positive reinforcer, that is, a reward that users do not have to learn to enjoy. The action is reinforced: The results make them want to do it again.
Undesirable drug or alcohol use can be discouraged by creating unrewarding consequences (for example, prison for drug abusers); by limiting access to the reward (raising the price of alcohol, arresting drug dealers); or by blocking the rewarding effect with another drug, such as the opiate antagonist naltrexone.