My two lunch buddies fall into two categories of "Asian-American":
One is the more typical example. He's a child of voluntary immigrants, self-selected people from their nation of origin.
The other is a child of refugees who fled their homeland.
The refugee descendant has a much more typical level of financial dysfunction in his family, but still far better than the "underclass" elements in the US native-born population.
As someone who grew up in an Appalachian family that has been in the US for over 300 years, cultural dysfunction plays a HUGE role in academic failure.
Let's be honest here:
The advent of birth control has now created a situation where people who don't have their shit together are going to reproduce at a higher rate than those that do. My metric for cultural dysfunction is whether a family raising kids "has their shit together" and teaches productive habits to their kids. Foods, music, language are just the visible cultural traits. Much less obvious are the habits of timeliness, respect for authority, willingness to examine one's OWN role in failure before jumping to blame others, etc.
The key issue in the US is we don't have a conversation about cultural differences, and instead have a conversation about racial differences, which completely obscures the real issue.
60%+ of black American children are born out of wedlock. This isn't caused by some magic gene. This is a sub-culture within the black American population that has cultural dysfunction that matches that of some of the bad elements at play within my Appalachian relatives.
We know that poverty isn't the root cause. Equally poor Latino and white communities have much higher percentages of fathers present in the household. Incarceration rates don't explain the gap either. Culture is almost certainly the answer.
I say this as a person who spends a lot of time helping the neighborhood kids who are playing with my son every afternoon. Almost all of them have parents who, contrary to the narrative pushed out, are not working 60 hours a week at 2 jobs. No, they are working 40 hours or less at a crappy job, and then invest their time/resources into blowing off steam at the end of the day. Car hobbies, drinking, NFL games, but helping their kids do their homework? No way. A lot of them don't even bother TELLING their kids to do their homework.