Texan and Scottish researchers have found people born in the US suffer the effects of poverty more than in other western countries while studying the relationship between poverty and IQ.
Lack of access to healthcare and education contributed.
The new research, aimed at studying intelligence genes and childhood social factors, combined the results of 14 separate studies of 25,000 sets of twins and siblings from the US, Australia, Sweden, Germany and the Netherlands. Using meta-analysis, researchers concluded that a person’s social environment can override their genetic potential for intelligence, at least in the US.
“The authors determined that childhood poverty appears to reduce the potential contained with a person’s genes, and that the situation varies from country to country. Poverty seems to have the biggest impact in US,” according to a statement from the University of Texas, Austin.
The researchers concluded that the differences between the US and European countries may be due in part to the latter’s better access to healthcare, which has helped to close some socioeconomic gaps. The link between poverty and a lower IQ was less noticeable in western Europe and Australia, but not in the Netherlands. They also found differences between educational systems could have an impact.
“The hypothesis that the genetic influence on intelligence depends on socioeconomic status was not supported in studies outside of the US,” said Tucker-Drob, associate professor at the University of Texas, Austin and co-author of the study.
Professor Timothy Bates from the University of Edinburgh’s Department of Psychology said that studies from Australia and Britain showed that IQ had high levels of heritability, something that was equal across all social classes.
“We showed that Britain and Australia have created a level playing field where class is no longer a limiting factor for the expression of genetic potential,” Professor Bates told the Daily Mail Online.
The researchers argued that offering better access to education and healthcare could counter and possibly reverse the negative effect poverty has on IQ-related genes.
“Once such characteristics are identified, they could inform policies directed at narrowing test score gaps and promoting all of the positive consequences of higher IQ, such as heath, wealth, and progress in science, art and technology,” Bates added.
The study was published in the journal Psychological Science.