An anonymous reader writes: New research published in the journal Psychological Science (abstract) found that children who grow up in poverty within the United States tend to have lower IQs than peers from other socioeconomic brackets. Previous studies have shown a complex relationship between a child's genetics, his environment, and his IQ. Your genes can't pinpoint your IQ, but they can indicate a rough range of values within which your IQ is quite likely to fall. For kids in poverty, they seem to consistently end up on the low end of that window. Interestingly, this effect was not seen for any of the other countries hosting kids within the study, which included Australia, Germany, England, Sweden, and the Netherlands. The study authors speculate that "inequalities in educational and medical access in the U.S." may be the root of the differences, though another researcher is planning to study the effect of school environments as well.