There are two factors that determine an individual's intelligence. First,is the sort of brain the human brain is very different, some people are more capable than others. The second factor, what happens to the environment, it is likely that his brain fails to develop.
So, the environment, thus affecting the wisdom of the people, such as twins Peter and Mark. Peter was raised poor. Poor educational opportunities. Mark was raised in a good home. He was a great educational opportunity. Upon entering the teenage years They have been tested to measure intelligence with Peter IQ was 85, which is low and Mark IQ was 125 is high.
Concluded that the intelligence of each person is different. There are two factors: the sort of brain and environmental.