 An individual will be more motivated to perform a particular activity if he knows that he will partake in a more desirable activity as a consequence.Stated objectively, if high-probability behaviors (more desirable behaviors) are made contingent upon lower-probability behaviors (less desirable behaviors), then the lower-probability behaviors are more likely to occur.More desirable behaviors are those that individuals spend more time doing if permitted; less desirable behaviors are those that individuals spend less time doing when free to act.