Check out this video for the results of a study about what motivates people:
Mechanical tasks result in better results proportionate to the reward, usually monetary.
Cognitive tasks result in poorer results if the monetary reward is substantial.
Another result is the notion that people will do things of value in any situation if they're allowed to, or as the moderator says, " we just get out of their way".
Malcom Gladwell also talks about this in his book The Outliers.
Velly velly interesting.