According to some research, 75 percent of our intelligence comes from our parents so it is genetical. But on the other hand, the place that we live in affects 25 percent of our intelligence as well. But in other researches, they say that it depends on the age.
In some researches, they say that the intelligence comes from the mother genetically. They say that intelligence genetics reside on the x chromosome. In boys (xy) the intelligence only comes from the mother while in girls (xx) the intelligence comes from both mother and father. And the 75 percent of the intelligence is genetical.
The environmental factors are less than the genetical factors but they are also factors which affects the intelligence as well. Some diseases, mental illness, physical and mental abbuse are one of the environmental factors.
In summary, there are more genetical factors which affects the intelligence. But there are some environmental factors as well, even if it is less than the genetical factors. So we can say that the intelligence is mostly genetical. But these are just researches. There isn’t a certain idea.