yeap, I'm pretty interested into this subject also. I don't have any grounds in this field, it's just about personal experience in dealing with smart/dumb people. and it's not related only to being smart or not, it's related to everything, even sports. I've met people who've set their mind to be great at something and they succeeded.

I'm not talking about those exceptions who read or write when others can barely speak, I'm referring to the majority here. I don't agree with one of your points: intelligence is not changeable by effort, it's actually changeable by mindset and self confidence.

For example the number one guy in my university was also the guy working the most. but he was not brilliant, he was only really determined to be the best. thanks for your comments ;)