It is often said that people should be rewarded for doing a given job in proportion to the effort it costs them to do...

Okay, so I got the answer right. But I am SO lost about how it would effect positively only those with the least skill or natural aptitude. Those seem like opposites to me. If someone has natural aptitude for a certain task it is easy for them, thus they would be negatively effected because it would cause them less effort to do a task, so they would be paid less. Someone please clear this up for me!