How rewards can back fire!

Reading this article it really intrigued me. It was to determine if people perform better or worse based on an award recieved or not. The article took three different groups and promised one group an expected award, one a surprise award, and one group none at all. Based on the awards they would receive they were told to draw. The study proved that those who were expecting an award drew far less spontaniously and the ones who didn't still just drew simply for fun. This article i thought related to the real world of adults who go to work everyday or so on. Some work harder because they want a bonus. Some already enjoy their jobs and seek no further award. To me that is how it should be becuase clearly according to the results of this article those that werent expecting award continued to put more effort into their projects anyway. I mean i don't swim for the first place medals (even if they are nice!) I swim for the love of the competition. So maybe this article was true, rewards can backfire!