I agree with you people can achieve their potential in the USA better then other countries. I think that is the difference.
There is a corlation between people being able to achieve their potential and wealth or between IQ and wealth.
A Few Thoughts on IQ and the Wealth of Nations | VDARE.com
The IQ structures of the two giga-countries, China and India, demand more intense study, in part because the future history of the world will hinge in no small part on their endowments of human capital. The demography of India is especially complex due to its caste system, which resembles Jim Crow on steroids and acid. By discouraging intermarriage, caste has subdivided the Indian people into an incredible number of micro-races. In India, according to the dean of population genetics, L.L. Cavalli-Sforza, "The total number of endogamous communities today is around 43,000"¦" We know that some of those communities - such as the Zoroastrian Parsees of Bombay - are exceptionally intelligent.
But we can't say with any confidence what is the long run IQ potential of Indians overall. Their current IQ score (81) is low, especially compared to China (100), the other country with hundreds of millions of poor peasants. Yet, keep in mind just how narrow life in rural India was for so long. In 1952, on the fifth anniversary of independence, the Indian government commissioned a survey to find out if the average Indian villager had heard yet that the British had gone. The study was quietly cancelled when early results showed that the average villager had never heard that the British had ever arrived!
It appears likely that some combination of malnutrition, disease, inbreeding, lack of education, lack of mental stimulation, lack of familiarity with abstract reasoning and so forth can keep people from reaching their genetic potential for IQ. Lynn himself did early studies demonstrating that malnutrition drives down IQ.