A meta-analytic review of experiments examining the effects of extrinsic rewards on intrinsic motivation.

Abstract

A meta-analysis of 128 studies examined the effects of extrinsic rewards on intrinsic motivation. As predicted, engagement-contingent, completion-contingent, and performance-contingent rewards significantly undermined free-choice intrinsic motivation (d = -0.40, -0.36, and -0.28, respectively), as did all rewards, all tangible rewards, and all expected rewards. Engagement-contingent and completioncontingent rewards also significantly undermined self-reported interest (d = -0.15, and -0.17), as did all tangible rewards and all expected rewards. Positive feedback enhanced both free-choice behavior (d = 0.33) and self-reported interest (d = 0.31). Tangible rewards tended to be more detrimental for children than college students, and verbal rewards tended to be less enhancing for children than college students. The authors review 4 previous meta-analyses of this literature and detail how this study's methods, analyses, and results differed from the previous ones.By 1971, hundreds of studies within the operant tradition (Skinner, 1953) had established that extrinsic rewards can control behavior. When administered closely subsequent to a behavior, rewards were reliably found to increase the likelihood that the behavior would be emitted again, an effect that persisted as long as the reward contingency was operative. When rewards were terminated, the likelihood that the behavior would be emitted eventually returned to the prereward baseline. This general finding led to the widespread advocacy of rewards as a motivational strategy, and behavior-change programs based heavily on the use of rewards were introduced into a variety of applied settings.In 1971, Deci (1971 argued that some activities provide their own inherent reward, so motivation for these activities is not dependent on external rewards. In line with White (1959), Deci referred to such activities as intrinsically motivated and raised the question of how extrinsic rewards would affect people's intrinsic motivation for these activities. Research reported in that and subsequent papers (Deci, 1971(Deci, , 1972a(Deci, , 1972b revealed that tangible rewards (viz., money) could undermine college students' intrinsic

Mentoring, educational services, and incentives to learn: What do we know about them?

“…Other experiments finding that people who were not paid at all exerted greater effort than those who were paid a small amount include Wilson, Hull and Johnson, 1981;Kohn, 1993;Frey and Jegen, 2000;and Heyman and Ariely, 2004, among others. More recently, laboratory research attempting to quantify the effect of external factors on intrinsic motivation has yielded mixed conclusions: Cameron et al, 2001, conducted meta-studies of over 100 experiments and found that the negative effects of external rewards were limited and could be overcome in certain settings -such as for high-interest tasks -but in a similar meta-study Deci et al, 1999, concluded that there are often negative effects of rewards on task interest and satisfaction. 6…”

Extrinsic and intrinsic motivation at 30: Unresolved scientific issues

“…This has not been done for undermining theory. Both free-choice and selfreport measures have been used, but these measures often produce different results when used in the same experiment (Deci, Koestner, & Ryan, 1999;Eisenberger, Pierce, & Cameron, 1999).…”

“…To overcome the measurement problems summarized in Table 2, Deci et al (1999) advised that we limit our interest to those studies in which the results of both free-choice and self-report measures are in agreement. The suggested remedy, however, is invalid.…”

“…They sought higher methodological standards for studies that did not show undermining effects than for those that did not. As an example, Deci et al (1999) asserted that metareviews should include only studies with initially high-interest activities, because of the possibility of floor effects with activities of initially low interest. Deci et al did not realize that potential ceiling effects could be misinterpreted as undermining effects when half the participants in an experiment randomly experienced increased interest and the other half randomly experienced decreased interest.…”

“…The theory makes the same prediction, for the same reasons, whether the initial level of interest is low, medium, or high, even though the term overjustification applies only to situations in which the initial level of interest is high. If self-perception theory is taken as a guide, Deci et al (1999) erred in arguing that metareviews should be focused only on studies with initially high interest.…”