Why do some students learn faster?

I believe that some students learn faster because their brain naturally processes information at a faster pace. This is not necessarily their fault for some may have ADD or ADHD.
Also, the studies in the article showed that when when students were praised for their intelligence,they often wanted to take an easy test rather then a hard one. This shows that students must be encouraged to work hard without praise. Although the praise will come when they do well after working hard.
So in all, being a slow learner is not only the way the student’s brain works, but also how the student is raised.