New study reveals that only wealthy Americans realize genetic potential

In other words, in the U.S., a smart person from a low income family has less chance of doing well than if they came from a rich family, and a not smart person from a rich family has a good chance of being well off than if they came from a poor family.

http://www.scientificamerican.com/article/genes-and-the-american-dream/?WT.mc_id=SA_SP_20160404

New study reveals that only wealthy Americans realize genetic potential

By David Z. Hambrick on March 29, 2016

Nearly a century after James Truslow Adams coined the phrase, the “American dream” has become a staple of presidential campaign speeches.

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But the American dream is not just a pie-in-the-sky notion—it’s a scientifically testable proposition. The American dream, Adams wrote, “is not a dream of motor cars and high wages merely, but a dream of social order in which each man and each woman shall be able to attain to the fullest stature of which they are innately capable…regardless of the fortuitous circumstances of birth or position.” In the parlance of behavioral genetics—the scientific study of genetic influences on individual differences in behavior—Adams’ idea was that all Americans should have an equal opportunity to realize their genetic potential.

A study just published in Psychological Science by psychologists Elliot Tucker-Drob and Timothy Bates reveals that this version of the American dream is in serious trouble. Tucker-Drob and Bates set out to evaluate evidence for the influence of genetic factors on IQ-type measures (aptitude and achievement) that predict success in school, work, and everyday life. Their specific question was how the contribution of genes to these measures would compare at low versus high levels of socioeconomic status (or SES), and whether the results would differ across countries. The results reveal, ironically, that the American dream is more of a reality for other countries than it is for America: genetic influences on IQ were uniform across levels of SES in Western Europe and Australia, but, in the United States, were much higher for the rich than for the poor.

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What might explain this finding? The new study doesn’t pinpoint the cause, but the leading hypothesis is that social policies in countries like Sweden, Australia, and Germany create living conditions that facilitate genetic influences on intellectual functioning. In these countries, people have relatively equal access to high-quality education and healthcare, and childhood poverty rates are low. Much like fertile soil allows plants to reach their maximum height, these conditions are hypothesized to promote the expression of any genetic differences in IQ that exist. By contrast, in the U.S., an estimated 33 million people still do not have health insurance, and there are dramatic differences across school districts in quality of education.

The results of Tucker-Drob and Bates’ analysis are as important as they are sobering. As economists have documented, the gap between the rich and poor in the United States is vast and widening. As a consequence, large numbers of Americans cannot afford even the basic necessities of life. Until they can, the American dream will likely remain a dream that these Americans have little hope of fulfilling.