Charles Murray, author of the controversial book The Bell Curve, tackles the question of whether all children are capable of academic success.
Murray argues that IQ is the strongest influence on academic success and that some children simply aren’t equipped to excel at the highest levels, no matter how excellent the schooling they receive. The children of parents from the professional classes tend to do better academically, he proposes, because they inherit higher IQ from their parents, and because the households of professional couples are more conducive to learning.
As the author clarifies in the comments:
Central to [Murray’s] claims is the idea that academic achievement is largely influenced by IQ, which is largely inherited. Yet from my little knowledge in this area I find these claims appear to conflict with new psychology research, showing, for example, that self-discipline is actually more important than IQ when it comes to academic success. Other research has shown that working memory training can boost intelligence scores.
The heritability of IQ is an interesting, if heated, topic of discussion. The Wikipedia entry is a great resource.