Scientists are discovering the source of human genius and getting close to the point that brain scans will be capable of evaluating intelligence. Mere appearance of the organ isn't enough:
"If I showed you two brains side by side, one with an IQ of 150, one with an IQ of 75, I can't tell the difference," says Jay Giedd of the National Institute of Mental Health, one of the most experienced researchers in the field.
But brain scans can do better.
But Jung and his colleague Dr. Richard Haier of the University of California, Irvine, claim they are on the verge of refining imaging techniques to a point that would make traditional intelligence tests obsolete.
"We can make quantitative assessments of how much gray matter they have in every single area, and we can use that to predict what their IQ might be," Haier says. "This is in the very early stage, and I think this is going to be very interesting."
Brain imaging remains in some ways as crude a tool as simply cutting open the brain and looking inside. Haier and Jung use magnetic resonance imaging (MRI) to measure various parts of the brain. Then they compare the pictures to intelligence scores on a verbal or pen and paper test.
So far, says Haier, he has found a strong correlation between intelligence and the size and shape of certain brain structures -- including parts of the superior parietal lobe (involved in sensory perception) and parts of the prefrontal cortex (associated with complex thinking, personality, planning, coordination).
Intelligence research is full of surprises. For example, the brains of smarter people, as measured by IQ, tend to be less active but more efficient, Haier says.
The final paragraph quoted above dovetails nicely with a Scientific American article from July about "The Expert Mind" which argued that Chess Grandmasters don't simply think more moves ahead than lesser players, they "chunk" more efficiently and thereby create more useful heuristics that let them solve more difficult chess problems with the same amoung ot brainpower.
In the context of chess, the same differences can be seen between novices and grandmasters. To a beginner, a position with 20 chessmen on the board may contain far more than 20 chunks of information, because the pieces can be placed in so many configurations. A grandmaster, however, may see one part of the position as "fianchettoed bishop in the castled kingside," together with a "blockaded king's-Indian-style pawn chain," and thereby cram the entire position into perhaps five or six chunks. By measuring the time it takes to commit a new chunk to memory and the number of hours a player must study chess before reaching grandmaster strength, Simon estimated that a typical grandmaster has access to roughly 50,000 to 100,000 chunks of chess information. A grandmaster can retrieve any of these chunks from memory simply by looking at a chess position, in the same way that most native English speakers can recite the poem "Mary had a little lamb" after hearing just the first few words.
So here are some questions: if the results were to be published, would you submit yourself to a brain-scan intelligence test? If there were a private organization that performed the tests and everyone believed they were reasonably accurate, would they become as standard as the SAT? Would they have more affect on society than SAT scores?