How can I know that my perception of the color red is the same as yours, when my experience of the color occupies a private mental world to which nobody else has access?
Research from Washington University in St. Louis has identified variations in brain scans that they believe identify portions of the brain that are responsible for intelligence.
As suspected brain size does play a small role; they said that brain size accounts for 6.7 percent of variance in intelligence. Recent research has placed the brain’s prefrontal cortex, a region just behind the forehead, as providing for 5 percent of the variation in intelligence between people.
The research from Washington University targets the left prefrontal cortex, and the strength of neural connections that it has to the rest of the brain. They think that these differences account for 10 percent of differences in intelligence among people. The study is the first to connect those differences to intelligence in people.
“Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is,” suggests lead author Michael W. Cole. […]
One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a “flexible hub” that uses its extensive brain-wide connectivity to monitor and influence other brain regions in a goal-directed manner.
“There is evidence that the lateral prefrontal cortex is the brain region that ‘remembers’ (maintains) the goals and instructions that help you keep doing what is needed when you’re working on a task,” Cole says. “So it makes sense that having this region communicating effectively with other regions (the ‘perceivers’ and ‘doers’ of the brain) would help you to accomplish tasks intelligently.”