While intelligence resides everywhere in our brains, researchers have also discovered that the most efficiently wired brains also tend to belong to really intelligent people.
After analysing the brain as an incredibly dense network of interconnected points, a team of Dutch scientists came to their conclusions.
According to Martijn van den Heuvel, a neuroscientist at Utrecht University Medical Center who led the new study, the "networked brain" concept isn't so different from the transportation grids used by cars and planes, reports New Scientist.
"If you're flying from New York to Amsterdam, you can do it in a direct flight. It's much more effective than going from New York, then to Washington, and then to Amsterdam. It's exactly the same idea in the brain," he says.
To reach to their answers, van den Heuvel's team mapped the communications between tiny slivers of brain measured by a functional magnetic resonance imaging (fMRI) machine. Rather than scan the brains of subjects performing mental tasks, as most fMRI studies do, researchers took 8-minute-long snapshots of the brains of 19 volunteers, as they did nothing in particular.
The subjects' brains and the researchers reasoned that any brain activity they measured represented underlying connectivity between brain regions, near and far. And thus, allowed van den Heuvel's team to build connectivity networks for each volunteer, and to measure the efficiency of each network.
"It more or less reflects how many steps a [brain] region has to take to send information from one region to another," he says.
This measure proved a decent predictor of each person's IQ, explaining about 30 per cent of the differences between subjects, van den Heuvel says.
The researchers found no link between the total number of connections in a subject's brain network and their IQ.
"We show that more intelligent people don't have more connections, but they have more efficiently placed connections," he says.