Originally posted by: ChameliKaYaar
Genes inside human cells determine the entire structure of human body (shape, size, traits etc.). The 23 (or 22) pairs of chromosomes contain all the vital information about how human body (including brain) will mature. These chromosomes are passed from parents to children. Therefore the intelligence (brain power) is hereditary.. to some extent. However every part of Human Body is a fantastic machine which needs consistent exercise to flourish and function. That includes brain as well. Strong genes are of no use if the mind is not exercised to the fullest extent. So, in my opinion, the intelligence is a combination of your genetically inherited thinking power (through chromosomes) and constant workout.
I had friends in my university whose brain were like sponge who would just soak it all up and they required very little revision before examination and then there were others who required "hours of mugging" to soak up the same material.
Wellsaid Mr Chameli Ki Yaar ji.