Tom's Young Cousin Is Intellectually Impaired

Essay

Tom's young cousin is intellectually impaired.Tom just read an article about a twin study that found that intelligence is 60 percent genetic,so he complains that his cousin was born unintelligent because her parents are not intelligent and there is nothing she can do about it.
A) Discuss whether you think Tom's conclusion is correct.
B) What other explanations can you think of that would explain Tom's cousin's learning problems? (Hint: What could have happened to her prenatally to influence her mental abilities?)