This is a classic argument in biology. Is DNA (nature) more important to the final product or is nurture (environment)? The answer is easy at the extremes. For example, someone who is 3'6" will never make it in the NBA, no matter how many basketball camps they attend. And the same may be true of a mentally retarded person, that they will never attain higher levels of education no matter how many tutors they have.
But the middle segments of the human population are where the arguments are most hotly debated. Given human beings of average ability and genetics it is clear that the differences between nature and nurture are much less sensitive. Even a child from a less than perfect family will achieve substantially if they are treated with love and interest.
However this question is phrased far too broadly and needs to be much more specific.