I think it's important to consider this factor when we try to gauge the likely efficacy of advice and strategies that have emanated from that vast collection of social milieux. I was delightfully surprised when I happened upon this graph this morning that neatly illustrates what I mean.
Although it might be a little difficult to see at this size, there's Canada above the line, in the upper, left corner. Our income inequality needs improvement but our social mobility is similar to that of the Scandinavian countries. Meanwhile, in the United States, on average, your status at birth is your status at death.