Pervasive negative effects of rewards on intrinsic motivation: The myth continues.

Weiss et al. (2001) pooled every lab and classroom experiment they could find on rewards and motivation. They looked at whether stickers, money, praise, or toys made people less eager to do the task later on their own.

The team separated studies by how fun the task was and how the reward was given. They counted free rewards, pay-for-performance, and verbal praise as different animals.

The big fear—that rewards always kill inner drive—was mostly a myth. When the task was boring or the reward was tied to doing well, people stayed interested.

Free goodies given just for showing up sometimes lowered later interest, but even that effect was small and vanished quickly.

Jennett et al. (2003) seems to shout the opposite. They gave children free candy every few minutes and saw more errors and a slide to easier puzzles. The clash is solved by looking at the reward rule: K used non-contingent freebies, while J’s meta shows harm only when rewards are not tied to performance.

Ghosn et al. (2023) backs J up. Autistic youth got faster and made fewer mistakes when social or tangible rewards were delivered for correct responses. The two studies line up—contingent rewards help.

Friedling et al. (1979) adds historical color. Self-instruction alone flopped for hyperactive kids until tokens were added. The pattern is the same: external reinforcement is often necessary, not harmful.

Stop warning teachers and parents that ‘rewards kill motivation.’ Instead, check the task. If it is dull, or if the learner has autism or ADHD, deliver praise or tokens right after correct responses. Skip free goodie bags that do not require work. Use J’s rule: contingent rewards are safe and often boost both performance and later interest.