You may think that the great genius Albert Einstein had a remarkable brain which is different from the “normal” humans.
But , no. He had the same brain structure as us (Ofcourse it is not identical since no human brain is identical in structure to any other ).He didn't possess any different brain part that we don't have.
Why?
The simplified version of how some people think better than others ( or perform intelligent acts):
We have different regions for performing different actions . This is the basic structure in our brain. For example, hippocampus is used in dealing with converting short to long term memories.
So , when we try to perform some action, we try to involve more than one part of the brain ( Like visually recognising a picture , understanding the abstract nature of something and give an analytical response)
What makes someone better than others is that the strength of the neural connections between the parts.
So , if you need to be good at something (IQ) , you need practice , which strengthens your neural connections and which helps you to perform each model of the IQ questions better.
Ofcourse , Einstein's analytical and abstract part of brain is more thickened/connected because of thought experiments where he visualizes stuff and analyses it and performs math regarding it.
TL;DR: practice makes a man perfect. Practice in a field makes you more skilled . In your case , you'll become more intelligent ;)