No it isn't,in fact studies have shown identical twins raised in totally different environments will grow up to have not only almost exactly the same IQ but also similar personalities.
The same is true of children whose biological parents have high IQ's,even when they are adopted out to parents with low IQ's they still grow up to be like their biological parents,the reverse is true also and the same goes for personality.
What you think seems perfectly reasonable,but the actual evidence shows it's not.
I've already put evidence up that proves this.
I'm well aware of r and K type br