Extrinsic rewards can be abused to bribe or coerce someone into doing something that they would not do on their own.
Extrinsic rewards reduce intrinsic interest.
The use of extrinsic rewards by parents is related to less generous and less intrinsically motivated behaviors by their children. Extrinsic rewards can be controlling. That Encourage Intrinsic Motivation Specific Classroom Management Methods Resources Extrinsic rewards do not produce permanent changes First and foremost, studies have shown that extrinsic rewards do not produce changes that are permanent. Thus, changes in behavior, as a result of extrinsic rewards, are due to an external motivator, not to an innate desire. Token economies, a system of providing money-like tokens for correct behaviors, have been proven to be ineffective.