Premack's Principle

Premack's principle, also called the relativity theory of reinforcement, is the finding in operant conditioning that a more probable behavior, one an organism performs readily and often, will reinforce a less probable behavior, one it performs less readily, when access to the more probable behavior is made contingent on first performing the less probable one. The principle is named for the psychologist David Premack, and it reframes reinforcement itself: rather than treating a reward as a fixed stimulus that either does or does not strengthen behavior, it treats the OPPORTUNITY to engage in a preferred activity as the reinforcer for a less preferred one, so which behavior counts as a reward for which other behavior depends on each individual's own relative preferences rather than being fixed in advance.