A few hundred dollars (that they brought into the boat) in Vietnam in 1970s might be a lot of money (at least by the then Chinese standards), it was not much in US.
On top of being as poor if not poorer than their neighbors, they did not speak English, so they were at an even more disadvantageous position economically.
The only difference is their brains and how they influence their children. Here is how it goes (according to an article published in Scientific American which was based on publications in peer reviewed journals): after dinner, the small dining table was cleared and children would study on using table, and parents would supervise even though they do not understand what were going on.
