Intelligence is genetically linked. Albert Einstein was not an intellectual product of his environment. There are no environments capable of producing genius.
If genius cannot be environmentally produced, and it can’t, then the only logical explanation would be heredity.
On the other hand, the movie, Good Will Hunting, portrays what a bad environment can do for a genius. In other words, being abused, outnumbered and ignored pushes genius in the back ground. Geniuses can and do become the janitors, mechanics and waitresses. And it is not unusual that they drink excessively or use drugs, because of the mind screw.
To be born intellectually superior and it not be recognized is something of a mind blow. As though a part of you is invisible. It does foster a certain disdain for those less endowed. Michaelangelo said, “Genius is eternal patience”. The young genius is patient to start her life as she watches her schizophrenic mother hop around on the floor with a knife, replaying some demon movie she saw. The young genius is patient to start her life as some big boobed carney social worker laughs in her face after she’s been driven to her knees in front of her three children.
Oh, yes, intelligence is inherited.
To the other extreme, mental retardation caused by the extra chromosome, known as Down Syndrome has shown that environment can make a difference in the behavior of the one afflicted. There are lots of people with Down Syndrome who can learn and are trained for jobs. They also learn a certain independence. There are others who do not do very well because of their environment. They end up institutionalized.
Back in 1921, a man named Terman began a study of the gifted. At that time, the common and popular belief was that gifted people “were sickly, socially inept, and not well-rounded”. He proved this belief to be wrong. He also proved that environment makes a huge impact on intelligence. Many of the female children he followed in his study grew up to be housewives. Instead of pioneering researchers or artists or mathematicians.
My conclusion is that intelligence is inherited and it’s level is not set by the parents intelligence. Intelligence is not easily assessed by behavior or individual production due to a shifty environment.