Why are certain people smarter than others?

I think passion has something to do with it.
I love maths but wouldnt say I was natural at it.
some things just come to me, some things I have to work at.
I'm gonna have to check out that movie though.

I've always believed intelligence is a combination of nature and nurture.

It's a combination of genetiics and environment. Nothing more to say to it than that really. Of course certain downsides can be overcome with a good work ethic, but talent that works hard beats plain old hard work.

Would you say how you are raised contributes in some way? For example, if you were raised by parents who are highly intelligent and educated themselves, are you more likely to be as well as opposed to parents who aren't? I'm very curious to find out opinions on this subject matter!

Well that's what I mean by environment. I think good genetics perhaps trumps environment, but who knows, both are certainly important. I wasn't raised in an intellectual household, but genetically the bloodeline I take after (my fathers) is incredibly intellectual (grandfather was a head of Astrophysics at Harvard, etc.) and, not to sound conceited, I do believe it passed down to my father and then to me, though maybe not quite to the level I'd have liked!

Influence, passion and natural intelligence.
Scientists aren’t sure but they think its to do with how the brain communicates between the left and right hemisphere. Also looking at the brains of classed geniuses, they seemed to have a cerebrum that was considerably large (i think it was 15% larger). The part of the brain responsible for logical thought and memory.

It's grinding, mostly grinding.

It's no surprise how good the Chinese and Singaporeans are at Math with attitude society has of always working hard.

Assuming you're of normal intellect, don't bother using excuses like "I'm not wired for maths or sciences". ******** excuses like these are what separates successful people in academics and failures.*

*there will always be anomalies in the form of prodigies and the disabled, however the vast majority of people will not fall in to these categories.

it is like "why are certain computers more powerful than others ?"

the answer will be a blend of

i) better hardware/ faster chips

ii) better software

however even the best computer must be operated correctly; if you are a genius you need discipline and application to produce world changing results.