Source: Science Daily
Childhood environment and socioeconomic status affect cognitive ability and brain development during adolescence independently of genetic factors, researchers at Karolinska Institutet report in a new study published in the journal PNAS. The study demonstrates how important the family environment is, not just during early infancy but also throughout adolescence.
At the age of 14, genes and the environment were independently associated with cognitive ability (measured using working memory tests) and brain structure. The environmental effects were, however, 50 to 100 percent stronger than the genetic. Differences in socioeconomic status were related to differences in the total surface area of the neocortex.
Genetic differences were also linked to the brain structure, affecting not only the brain's total area but also specify an area of the right parietal lobe known to be important for mathematical skills, reasoning and working memory. This is the first time a brain area has been identified that is linked to this genetic index.
When the researchers followed up on the teenagers five years later, they were able to examine how genes and environment had affected the brain's development during adolescence. What they discovered was that while the genes did not explain any of the cerebral changes, the environment did.