The Idiocracy May Be Here, But It Isn't Hereditary
The more education people obtain, the fewer children they have. Scientists can now use big data to explore the implications of this well-documented sociological trend, which has spawned much fretful speculation on the future of the gene pool.
Academics talk about a sort of genetic degradation known as “dysgenics,” while films such as “Idiocracy” project that in 500 years, people will live in plastic huts and watch even dumber television than they do today.
The movie was an innocuous spoof on pop culture of the early 2000s, but dysgenics casts darker shadows. It’s a close cousin to the 20th-century eugenics movement, which advocated selective breeding of human beings, encouraging people with certain traits to reproduce while preventing others from propagating what were considered undesirable genes. While eugenics is associated with Nazi atrocities, the ideology flourished for awhile in the United States, where it led to the forced sterilization of tens of thousands of people.
There’s been much discussion of eugenics among medical ethicists, but the New York University sociologist Dalton Conley realized that there is enough genetic data available to test the scientific validity of eugenic or dysgenic claims. And so he and colleagues set out to see if the inverse relationship between education and fecundity had changed the distribution of genes.
Conley and colleagues used a database of 8,000 people spanning multiple generations – all in Michigan and all of European ancestry. They published the results of their analysis last week in the Proceedings of the National Academy of Sciences.
He said there were several sociological patterns associated with this group. First was the fact that more educated people had fewer kids, and this trend accelerated over the course of the century. There was also an increasing tendency for people to marry others of the same educational level. That, too, can influence the future of the gene pool by concentrating genes among certain groups.
The first question they set out to answer was whether they could find genes that had any connection to educational attainment. A study using this and other databases turned up 74 genetic markers with a weak education correlation -- a finding that was published last month in the journal Nature. Critics jumped on it, questioning whether the findings could or should be used to make any predictions about a person’s future based on a genetic test.
To Conley, that wasn’t the point. Many of the genes are probably not even connected to intelligence. He pointed out that sociologists have found that short men and overweight women are subject to prejudice at school and work, and both these factors are tied to genes.
Whatever the 74 genes did or did not do to further the academic careers of their carriers, the second part of the research showed that their distribution has remained unchanged over the course of the 20th century.
The database only covered a few generations and less than a century, but that’s plenty of time to see changes in the distribution of genes, said Stephen Stearns, a biologist at Yale University. No longer do scientists assume that evolution can only take place over thousands or millions of years, he said. “Evolution is simply about the increased representation of some genes in future populations and decreased representations of others,” he said. “So it will happen when anything changes the number of children or grandchildren people have.”
While some scientists, including David Attenborough, have speculated that humans have stopped evolving, others, such as Stearns, say we’ve simply altered the factors driving evolution. For us, evolution is now influenced by how many kids people decide to have, and less by who survives long enough to have kids, or who attracts the most potential mates.
He’s looked at ongoing evolutionary trends using another large set of health and genetic data on thousands of people in Framingham, Massachusetts. His conclusion, published in 2009, was that recent evolution has made women slightly shorter and a bit heavier.
Stearns said Conley’s results looked consistent with what they found in the Framingham data. But the new work was aimed at questions of interest to sociology, especially the issue of eugenics. “The bottom line is, we don’t have to worry about some sort of bad eugenic change,” he said. People are doing fine making their own reproductive choices, and there’s no reason to make educated people feel guilty if having kids isn’t in the cards for them.
And while some events of the last year may suggest that the 2006 predictions of “Idiocracy” are coming true early, it has little to do with our genes.
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