Carl Zimmer in The New York Times:
In the largest genetics study ever published in a scientific journal, an international team of scientists on Monday identified more than a thousand variations in human genes that influence how long people stay in school. Educational attainment has attracted great interest from researchers in recent years, because it is linked to many other aspects of people’s lives, including their income as adults, overall health and even life span. The newly discovered gene variants account for just a fraction of the differences in education observed between groups of people. Environmental influences, which may include family wealth or parental education, together play a bigger role. Still, scientists have long known that genetic makeup explains some of the differences in time spent in school. Their hope is that the data can be used to gain a better understanding of what educators must do to keep children in school longer. With a fuller understanding of the influences exerted by genes, scientists think they will be able to better measure what happens when they try to improve a child’s learning environment. The new study, published in the journal Nature Genetics, finds that many of the genetic variations implicated in educational attainment are involved in how neurons communicate in the brain. A striking number are involved in relaying signals out of neurons and into neighboring ones through connections called synapses. The findings are based on genetic sequencing of more than 1.1 million people. But the subjects were all white people of European descent. In order to maximize the odds of discovering genetic links, the scientists say they needed a very large, homogeneous sample.
When the team tried to use these genetic variants to explain differences in schooling time among African-Americans, the predictions failed. The researchers also found that genes don’t have a uniform effect: The influences of the genes varied from country to country. The researchers could not pinpoint the cause of these differences. But if educators in one country emphasize memory over problem-solving in math classes, for example, then some gene variants may provide a bigger benefit to some students than others, the scientists speculated. A truly global understanding of these genetic influences will require similarly huge studies of people of other ancestries, the researchers said.