Do rewards motivate people? Absolutely. They motivate people to get rewards.
Grades dilute the pleasure that a student experiences on successfully completing a task.
When was the last time you spent the entire day with only 42 year olds?
Children learn how to make good decisions by making decisions, not by following directions.
Unconditional parenting: Moving from Rewards and Punishments to Love and Reason.
The Legacy of Behaviorism: Do this and you'll get that.