There's an entire system organized around the idea that we're too weak to deliver effort without external rewards and punishment.

An overemphasis on external rewards, standards, and tests can deaden even a good student's desire to learn.

Adjustment function: A main motivation for individuals is to increase positive external rewards and minimize the costs.

Despite its external rewards, stage two is associated with the birth of guilt.

Earlier studies showed contradictory or inconclusive findings regarding decrease in performance on a task following an external reward.

This provides evidence that verbal praise as external reward increases intrinsic motivation.

The author explained differences between the two types of external rewards as having different effects on intrinsic motivation.

Why the effort for so long for so little external reward?

When intrinsically motivated a person is moved to act for the fun or challenge entailed rather than because of external rewards.

Extrinsic: reflects the desire to do something because of external rewards such as awards, money and praise.