A team of neurologists at the University of California have reportedly identified genetic variants which might indicate how intelligence works in the brain and how it might be improved. The team did this by analyzing brain images and whole-genome data from 472 subjects, including 85 pairs of identical twins, 100 pairs of non-identical twins, and their non-twin siblings.
This led to the discovery of 24 different genetic variations within six different genes linked to differences in the structural integrity of major brain pathways, which included the insulation of neural pathways that is responsible for how fast nervous impulses are routed in the brain.
While many of the genes were already known, they hadn't previously been linked to brain integrity. Some of the variants were associated with intelligence; those carrying these variations were actually scoring extra points on IQ tests. Even more impressive is that these variants appear to amplify each other's effects, which meant that possessing more than one provides a boost in intelligence.
But not everyone is buying into the study. Critics point out that researchers were looking at oversimplified statistics, and that their sample size was too small. There was also no replication done in the study, and that other appropriate data sets should have been used. Plus, s rare to see both IQ scores and brain imaging data used for such a study, and that the data is probably not comparable.