Genetic heritability, which is a subset of heritability, does not generally mean what people think it means, though. To the extent IQ can be attributed genetically to parents, it does not imply a "compounding" effect where smart people continuously have smarter kids and dumb people have dumber kids. This can understood by analogy to other personal traits like eyesight, height, weight, hair color, etc. which vary within a range across generations with occasional unpredictable outliers. This is why folks who do test for intelligence, have to test each person individually and not just rely on bloodline tracking.