Relying on rewards to influence behavior changes the motivation in children. Teachers of upper elementary grades through high school know this truth by the most common questions students ask: “Will the material be on the test?” and “Will this count on the grade?” Rather than being motivated by curiosity, the challenge, or the enjoyment of learning, the students’ motivation turns toward the external reward—the grade.
The motivation is to do well for the teacher’s evaluation, rather than for the learning itself. In addition, and this is rather obvious, the more emphasis placed upon the external reward of the grade, the more students look for the easiest way to obtain it.
Here is a paradox. Many studies have shown that the more we reward people for doing something for which they are not internally motivated, the more likely they are to lose interest in whatever they had to do to get the reward. In other words, the more emphasis we place upon the external motivator, the more students lose interest in what they are doing. Rewarding students for reading is a typical example. When students read for pay or for some prize, their long-term interest in reading declines. They will be motivated to read in order to obtain the prize, but they read less after receiving the booty.
Additionally, creativity declines when more emphasis is placed upon grades. You can prove this to yourself with any group of students. Give them an assignment and let them know that you are very interested in seeing what they can do with it. Be clear that you will not assign a grade. Then give a similar assignment and inform the students that the activity will be graded. See for yourself the decline in creativity.