[angry young man]

What do you think about the idea that study habits and discussions away from school have much to do with a child's success?

This point is interesting. I agree with you that the values of the household (which stem from cultural values) have a huge effect on scholastic (and other kinds) of success. I would expect that this has a larger effect on these trends than any genetic differences. There are issues that are ignored by these articles (perceived abilities effecting actual performance, for example) but I've always felt that it was clear some cultures placed much more value on education and this was reflected in their children's academic performance. You can divide it up racially to some degree [Asian and Jewish cultures, and even, to a degree, religious beliefs, certainly place a lot of value on knowledge and education; surprise their kids score well], but you can also see geographic and economic diferences in values. Essentially, if your family doesn't think school is important it's less likely that you'll do well, regardless of your ability.