Of course intelligence is genetic.  We are evolved.  Literally every single trait of human bodies is genetic.  Now, are the differences between people largely genetic?  Obviously.  You're born with it and you can't change it.  Are there cases of brain damage like lead poisoning that can affect the end product?  Obviously.  Can abuse and environment do brain damage or psychological damage, lowering the scores?  Damn right.<br><br>Can a good environment help you maximize your potential?  Duhhh.  Can a bad environment cause a lack of neural connections you had potential for? DUHHHHH