Motivation
There is a great difference between ability to do something, and the motivation to do it. For example, many people in Singapore have the ability to speak in Mandarin, but no motivation to do it. With motivation, however, someone without the ability to do something, might put in extra effort to do it. The end result might be better than using someone with the ability, but no motivation. Then again, that is speculation. What is for sure, is that if abilities are similar, the output of the motivated person is likely to be better.
Yet, in this day and age of computerisation, and data processing, a lot of this gets missed out. Statistics may show only people with A-grades for a certain subject in school, but leave genuine interest and motivation at the door. In truth, many people I know, who did Chinese as a First Language, have almost completely forgotten how to use the language, even if they scored As. However, there are people who did not even score As for their Chinese as a Second Language, and yet are pretty fluent to this day. Of course, this applies to any field of study, like how some students who read "pure science" in Secondary School, did worse than those who did "combined science", when they were doing their A-levels.
Yet, in this day and age of computerisation, and data processing, a lot of this gets missed out. Statistics may show only people with A-grades for a certain subject in school, but leave genuine interest and motivation at the door. In truth, many people I know, who did Chinese as a First Language, have almost completely forgotten how to use the language, even if they scored As. However, there are people who did not even score As for their Chinese as a Second Language, and yet are pretty fluent to this day. Of course, this applies to any field of study, like how some students who read "pure science" in Secondary School, did worse than those who did "combined science", when they were doing their A-levels.