However, the bottom line is that the immigrants that we get from Mexico are generally from the lower end of their bell curve and the dregs of their society. So we get their indigent, their illiterate, and their criminal. Their educated upper classes are happy where they are and aren't the ones who come over here. So it's not surprising that the average Mexican immigrant has an IQ in the 80's, and that their children are at the bottom rung of educational and economic achievement.
In contrast, immigrants from India or northeast Asia tend to be from the cream of their society, people with skills and education. That rather than intrinsic differences between Asians and Hispanics probably accounts for the pattern we're seeing.
Good points.